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Sample records for l-1-13cphenylalanine breath tests

  1. Breath alcohol test

    MedlinePlus

    Alcohol test - breath ... There are various brands of breath alcohol tests. Each one uses a different method to test the level of alcohol in the breath. The machine may be electronic or manual. One ...

  2. 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

  3. How to interpret hydrogen breath tests.

    PubMed

    Ghoshal, Uday C

    2011-07-01

    Hydrogen breath tests using various substrates like glucose, lactulose, lactose and fructose are being used more and more to diagnose small intestinal bacterial overgrowth (SIBO) and lactose or fructose malabsorption. Though quantitative culture of jejunal aspirate is considered as gold standard for the diagnosis of SIBO, hydrogen breath tests, in spite of their low sensitivity, are popular for their non-invasiveness. Glucose hydrogen breath test is more acceptable for the diagnosis of SIBO as conventionally accepted double-peak criterion on lactulose hydrogen breath test is very insensitive and recently described early-peak criterion is often false positive. Hydrogen breath test is useful to diagnose various types of sugar malabsorption. Technique and interpretation of different hydrogen breath tests are outlined in this review. PMID:21860825

  4. Hydrogen breath tests in gastrointestinal diseases.

    PubMed

    Rana, Satya Vati; Malik, Aastha

    2014-10-01

    Hydrogen breath tests are widely used to explore pathophysiology of functional gastrointestinal (GI) disorders. Small intestinal bacterial overgrowth (SIBO) and carbohydrate malabsorption are disorders detected by these tests that have been proposed to be of great importance for symptoms of GI diseases. Glucose hydrogen breath test is more acceptable for diagnosis of SIBO whereas lactose and fructose hydrogen breath tests are used for detection of lactose and fructose maldigestion respectively. Lactulose hydrogen breath test is also used widely to measure the orocecal transit time for GI motility. These methods are noninvasive and inexpensive. Many patients with functional gut disorders are unaware of the relationship between diet and GI symptoms they present. In particular, patients with chronic symptoms may regard their condition as normal and may not be aware that their symptoms can be effectively managed following a proper diagnosis. Patients with symptoms of abdominal pain, bloating, flatulence and altered bowel movements (diarrhea and constipation), or with a medical diagnosis of irritable bowel syndrome or celiac disease, may have undiagnosed carbohydrate malabsorption or SIBO. Hydrogen breath tests are specific and sensitive diagnostic tests that can be used to either confirm or eliminate the possibility of carbohydrate malabsorption or SIBO in such patients. Breath tests, though valuable tools, are underutilized in evaluating dyspepsia and functional bloating and diarrhea as well as suspected malabsorption. However, because of their simplicity, reproducibility and safety of procedure they are now being substituted to more uncomfortable and expensive techniques that were traditionally used in gastroenterology. PMID:25298621

  5. Breath Testing for Small Intestinal Bacterial Overgrowth: Should We Bother?

    PubMed

    Pimentel, Mark

    2016-03-01

    The hydrogen breath test is based on following breath hydrogen levels after the administration of a carbohydrate (most commonly lactulose) to a patient with suspected small intestinal bacterial overgrowth. The test is based on the interaction between the administered carbohydrate and the intestinal bacteria. The resulting fermentation produces hydrogen. A positive breath test is based on a breath hydrogen rise prior to the expected arrival time in the highly microbial cecum. Despite renewed enthusiasm for breath testing in recent years due to associations with conditions such as irritable bowel syndrome, breath testing poses many challenges. In this argument against breath testing, several pitfalls that complicate breath testing will be described. PMID:26902227

  6. Breathing air trailer acceptance test procedure

    SciTech Connect

    Kostelnik, A.J.

    1994-09-14

    This Acceptance Test Procedure (ATP) will document compliance with the requirements of WHC-S-0251 Rev. 0 and ECNs 613530 and 606113. The equipment being tested is a Breathing Air Supply Trailer purchased as a Design and Fabrication procurement activity for use in the core sampling program. The ATP was written by the Seller and will be performed by the Seller with representatives of the Westinghouse Hanford Company witnessing the test at the Seller`s location. This test procedure is to verify that the American Bristol Industries, Inc., Model 5014-0001 low pressure Mobile Breathing Air Trailer, meets or exceeds the requirements of the Westinghouse Hanford specification.

  7. Breath tests and airway gas exchange.

    PubMed

    Anderson, Joseph C; Hlastala, Michael P

    2007-01-01

    Measuring soluble gas in the exhaled breath is a non-invasive technique used to estimate levels of respiratory, solvent, and metabolic gases. The interpretation of these measurements is based on the assumption that the measured gases exchange in the alveoli. While the respiratory gases have a low blood-solubility and exchange in the alveoli, high blood-soluble gases exchange in the airways. The effect of airway gas exchange on the interpretation of these exhaled breath measurements can be significant. We describe airway gas exchange in relation to exhaled measurements of soluble gases that exchange in the alveoli. The mechanisms of airway gas exchange are reviewed and criteria for determining if a gas exchanges in the airways are provided. The effects of diffusion, perfusion, temperature and breathing maneuver on airway gas exchange and on measurement of exhaled soluble gas are discussed. A method for estimating the impact of airway gas exchange on exhaled breath measurements is presented. We recommend that investigators should carefully control the inspired air conditions and type of exhalation maneuver used in a breath test. Additionally, care should be taken when interpreting breath tests from subjects with pulmonary disease. PMID:16413216

  8. 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.

  9. 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...

  10. 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...

  11. 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...

  12. 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....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...

  13. 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....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...

  14. 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.

  15. 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... employed in lieu of the breathing tubes required. (c)(1) A flexible, nonkinking type breathing tube...

  16. 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... employed in lieu of the breathing tubes required. (c)(1) A flexible, nonkinking type breathing tube...

  17. 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... employed in lieu of the breathing tubes required. (c)(1) A flexible, nonkinking type breathing tube...

  18. 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... employed in lieu of the breathing tubes required. (c)(1) A flexible, nonkinking type breathing tube...

  19. Breathing air trailer acceptance test report

    SciTech Connect

    Kostelnik, A.J.

    1996-02-12

    This Acceptance Test Report documents compliance with the requirements of specification WHC-S-0251, Rev.0 and ECNs 613530 and 606113. The equipment was tested according to WHC-SD-WM-ATP-104. The equipment tested is a Breathing Air Supply Trailer purchased as a design and fabrication procurement activity. The ATP was written by the Seller and was performed by the Seller with representatives of the Westinghouse Hanford Company witnessing portions of the test at the Seller`s location.

  20. 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. PMID:24976698

  1. 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

  2. 42 CFR 84.88 - Breathing bag test.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing bag test. 84.88 Section 84.88 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Self-Contained Breathing Apparatus § 84.88 Breathing bag test. (a)...

  3. 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.

  4. Breath testing for small intestinal bacterial overgrowth: maximizing test accuracy.

    PubMed

    Saad, Richard J; Chey, William D

    2014-12-01

    The diagnosis of small intestinal bacterial overgrowth (SIBO) has increased considerably owing to a growing recognition of its association with common bowel symptoms including chronic diarrhea, bloating, abdominal distention, and the irritable bowel syndrome. Ideally, an accurate and objective diagnosis of SIBO should be established before initiating antibiotic treatment. Unfortunately, no perfect test exists for the diagnosis of SIBO. The current gold standard, small-bowel aspiration and quantitative culture, is limited by its high cost, invasive nature, lack of standardization, sampling error, and need for dedicated infrastructure. Although not without shortcomings, hydrogen breath testing provides the simplest noninvasive and widely available diagnostic modality for suspected SIBO. Carbohydrates such as lactulose and glucose are the most widely used substrates in hydrogen breath testing, with glucose arguably providing greater testing accuracy. Lactose, fructose, and sorbitol should not be used as substrates in the assessment of suspected SIBO. The measurement of methane in addition to hydrogen can increase the sensitivity of breath testing for SIBO. Diagnostic accuracy of hydrogen breath testing in SIBO can be maximized by careful patient selection for testing, proper test preparation, and standardization of test performance as well as test interpretation. PMID:24095975

  5. 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.

  6. 46 CFR 197.450 - Breathing gas tests.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... GENERAL PROVISIONS Commercial Diving Operations Periodic Tests and Inspections of Diving Equipment § 197.450 Breathing gas tests. The diving supervisor shall insure that— (a) The output of each air... commencement of diving operations, at the umbilical or underwater breathing apparatus connection point for...

  7. 46 CFR 197.450 - Breathing gas tests.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... GENERAL PROVISIONS Commercial Diving Operations Periodic Tests and Inspections of Diving Equipment § 197.450 Breathing gas tests. The diving supervisor shall insure that— (a) The output of each air... commencement of diving operations, at the umbilical or underwater breathing apparatus connection point for...

  8. 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... employed on Type C supplied-air respirators of the continuous flow class shall meet the...

  9. 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 Section 84.91 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Self-Contained Breathing Apparatus § 84.91...

  10. 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 Section 84.90 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Self-Contained Breathing Apparatus § 84.90...

  11. A Systematic Approach to Multiple Breath Nitrogen Washout Test Quality

    PubMed Central

    Klingel, Michelle; Pizarro, Maria Ester; Hall, Graham L.; Ramsey, Kathryn; Foong, Rachel; Saunders, Clare; Robinson, Paul D.; Webster, Hailey; Hardaker, Kate; Kane, Mica; Ratjen, Felix

    2016-01-01

    Background Accurate estimates of multiple breath washout (MBW) outcomes require correct operation of the device, appropriate distraction of the subject to ensure they breathe in a manner representative of their relaxed tidal breathing pattern, and appropriate interpretation of the acquired data. Based on available recommendations for an acceptable MBW test, we aimed to develop a protocol to systematically evaluate MBW measurements based on these criteria. Methods 50 MBW test occasions were systematically reviewed for technical elements and whether the breathing pattern was representative of relaxed tidal breathing by an experienced MBW operator. The impact of qualitative and quantitative criteria on inter-observer agreement was assessed across eight MBW operators (n = 20 test occasions, compared using a Kappa statistic). Results Using qualitative criteria, 46/168 trials were rejected: 16.6% were technically unacceptable and 10.7% were excluded due to inappropriate breathing pattern. Reviewer agreement was good using qualitative criteria and further improved with quantitative criteria from (κ = 0.53–0.83%) to (κ 0.73–0.97%), but at the cost of exclusion of further test occasions in this retrospective data analysis. Conclusions The application of the systematic review improved inter-observer agreement but did not affect reported MBW outcomes. PMID:27304432

  12. 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.

  13. 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 the apparatus). (b) The bag will be operated during this test by a breathing machine with...

  14. 14C-urea breath test in C pylori gastritis.

    PubMed Central

    Rauws, E A; Royen, E A; Langenberg, W; Woensel, J V; Vrij, A A; Tytgat, G N

    1989-01-01

    14C-urea breath test was used to detect Campylobacter pylori colonisation in 129 consecutive non-ulcer dyspepsia patients. Fasting patients were given 3 microCi (110 kBq) of 14C-labelled urea after a test meal. Breath samples were collected at 10 minute intervals for 90 minutes and the C-14 activity was counted on a liquid scintillation analyser. Urea derived 14CO2 appears in the exhaled breath of Campylobacter pylori culture positive individuals within 20-30 minutes. Likelihood analysis revealed a most favourable cut off level of [0.07% dose 14C-urea/mmol CO2] multiplied by body weight at t = 40 minutes, to separate culture positive from culture negative subjects. Using this upper limit of normal, a positive likelihood ratio of 50 and a negative likelihood ratio of 0.05 was calculated. Sensitivity of the test was 95% and specificity 98%. The 14C-urea breath test is a simple, sensitive and non-invasive test, that detects viable C pylori microorganism and semiquantitatively assesses the bacterial load of C pylori colonisation. Administration of a single dose of colloidal bismuth subcitrate resulted in a rapid decrease in 14CO2 excretion, so this test can be used to confirm eradication of the bacterium in therapeutic trials without endoscopy, or need for culture. PMID:2753404

  15. 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. 84.203 Section 84.203 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Chemical Cartridge Respirators §...

  16. The measurand problem in infrared breath alcohol testing

    NASA Astrophysics Data System (ADS)

    Vosk, Ted

    2012-02-01

    Measurements are made to determine the value of a quantity known as a measurand. The measurand is not always the quantity subject to measurement, however. Often, a distinct quantity will be measured and related to the measurand through a measurement function. When the identities of the measurand and the quantity actually measured are not well defined or distinguished, it can lead to the misinterpretation of results. This is referred to as the measurand problem. The measurand problem can present significant difficulties when the law and not science determines the measurand. This arises when the law requires that a particular quantity be measured. Legal definitions are seldom as rigorous or complete as those utilized in science. Thus, legally defined measurands often fall prey to the measurand problem. An example is the measurement of breath alcohol concentration by infrared spectroscopy. All 50 states authorize such tests but the measurand differs by jurisdiction. This leads to misinterpretation of results in both the forensic and legal communities due to the measurand problem with the consequence that the innocent are convicted and guilty set free. Correct interpretation of breath test results requires that the measurand be properly understood and accounted for. I set forth the varying measurands defined by law, the impact these differing measurands have on the interpretation of breath test results and how the measurand problem can be avoided in the measurement of breath alcohol concentration.

  17. 13C urea breath test for Helicobacter pylori: Evaluation of 10-minute breath collection

    PubMed Central

    Mauro, Marina; Radovic, Vladimir; Wolfe, Melanie; Kamath, Markad; Bercik, Premsyl; Armstrong, David

    2006-01-01

    AIM: To determine whether a shortened 13C urea breath test (13C UBT) (breath collection time of 10 min) is as reliable as the standard assay (30 min). METHODS: Two hundred ninety-seven patients (mean ± SD: 53±16 years, 57% female) completed a 13C UBT. Breath samples were obtained at baseline and at 5 min intervals up to 30 min. Sixty-seven patients also underwent endoscopic biopsy. Cluster analysis was performed on the 13C UBT data to determine the optimal cut-off point at each time interval. Sensitivity and specificity of the 13C UBT at all intervals compared with histology and culture and against the standard 30 min interval were determined. RESULTS: The calculated optimal cut-off points for each time interval (T), expressed as delta over baseline (δ‰), were 3.29 δ‰ at T5, 3.15 δ‰ at T10, 3.42 δ‰ at T15, 3.17 δ‰ at T20, 2.99 δ‰ at T25 and 2.82 δ ‰ at T30. Except at T5, the risk of false-positive and false-negative test results at each time interval was lower than 2.3% using these cut-off points. When replacing the cut-off points with 3.0 δ‰, the risk of error was still lower than 2.3%. The test at T10 showed 98.6% sensitivity and 98.6% specificity compared with T30. T10 and T30 showed 100% sensitivity and 96% specificity compared with histology and culture. CONCLUSIONS: The 13C UBT is an accurate, noninvasive test, even when the breath sample interval is reduced to 10 min. The present study confirms the validity of a cut-off point of 3.0 δ‰ for the 10 min and 30 min 13C UBT. PMID:17171196

  18. 49 CFR 219.206 - FRA access to breath test results.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 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...

  19. 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...

  20. 49 CFR 219.206 - FRA access to breath test results.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 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...

  1. 49 CFR 219.206 - FRA access to breath test results.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 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...

  2. 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...

  3. 49 CFR 40.277 - Are alcohol tests other than saliva or breath permitted under these regulations?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 1 2013-10-01 2013-10-01 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...

  4. 49 CFR 40.277 - Are alcohol tests other than saliva or breath permitted under these regulations?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 1 2012-10-01 2012-10-01 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...

  5. 49 CFR 40.277 - Are alcohol tests other than saliva or breath permitted under these regulations?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 1 2014-10-01 2014-10-01 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...

  6. Test-retest reproducibility of hydrogen breath test for lactose maldigestion in preschool children.

    PubMed

    Barillas-Mury, C; Solomons, N W

    1987-01-01

    The test-retest reproducibility of the H2 breath test within the same individual has not been rigorously evaluated in preschool children. In the present study, 10 children--5 of whom were diagnosed as lactose-digesters on their first testing, and 5 of whom were diagnosed as lactose-maldigesters at first screening--were retested under identical conditions of a second opportunity. In each case, the same diagnostic classification was provided, for a reproducibility of 100%. Regression of the area under the curve of the change in breath H2 concentration during the 3 h of the test had a Pearson's correlation coefficient of 0.59 (p = 0.05). The time-course of 3-h H2 breath tests in 43 children with lactose maldigestion revealed a peaking of the concentration of H2 most commonly 120 min following the oral dose of 240 ml whole milk. Seventy-seven percent of the children who eventually proved to be lactose maldigesters were so diagnosed by the end of the second hour of the breath test. Thus, even the abbreviated breath sampling schedule used in children is sensitive, and few maldigesters would go undetected because of a late rise in breath H2 concentration. PMID:3694351

  7. Assessment of the 14C-Glycocholic Acid Breath Test

    PubMed Central

    James, O. F. W.; Agnew, J. E.; Bouchier, I. A. D.

    1973-01-01

    The 1-(14C)-glycine-glycocholic-acid breath test has been performed on 104 subjects and a normal range established. Abnormal results due to bacterial deconjugation of bile salts were found not only in patients with the “contaminated bowel” syndrome and in those with ileal resection but also in a third group, patients with cholangitis. Abnormal results were also found in patients with gastrocolic fistula and staphylococcal enterocolitis, while mildly abnormal results were also found in some patients with liver disease. PMID:4718834

  8. 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.

  9. Breath tests to phenotype drug disposition in oncology.

    PubMed

    Opdam, Frans L; Modak, Anil S; Gelderblom, Hans; Guchelaar, Henk-Jan

    2013-11-01

    Breath tests (BTs) have been investigated as diagnostic tools to phenotype drug disposition in cancer patients in the pursuit to individualize drug treatment. The choice of the right phenotype probe is crucial and depends on the metabolic pathway of the anticancer agent of interest. BTs using orally or intravenously administered selective non-radioactive (13)C-labeled probes to non-invasively evaluate dihydropyrimidine dehydrogenase, cytochrome P450 (CYP) 3A4, and CYP2D6 enzyme activity have been published. Clinically, a (13)C-dextromethorphan BT to predict endoxifen levels in breast cancer patients and a (13)C-uracil BT to predict fluoropyrimidine toxicity in colorectal cancer patients are most promising. However, the clinical benefit and cost effectiveness of these phenotype BTs need to be determined in order to make the transition from an experimental setting to clinical practice as companion diagnostic tests. PMID:23868281

  10. 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. PMID:24438778

  11. 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)...

  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)...

  13. 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)...

  14. 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 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)...

  15. 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 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)...

  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. 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.

  18. (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. PMID:26527580

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. 46 CFR 197.450 - Breathing gas tests.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... commencement of diving operations, at the umbilical or underwater breathing apparatus connection point for the..., supplying mixed-gas to a diver, is checked, prior to commencement of diving operations, at the umbilical...

  5. 46 CFR 197.450 - Breathing gas tests.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... commencement of diving operations, at the umbilical or underwater breathing apparatus connection point for the..., supplying mixed-gas to a diver, is checked, prior to commencement of diving operations, at the umbilical...

  6. 46 CFR 197.450 - Breathing gas tests.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... commencement of diving operations, at the umbilical or underwater breathing apparatus connection point for the..., supplying mixed-gas to a diver, is checked, prior to commencement of diving operations, at the umbilical...

  7. Phase V of the single-breath washout test

    NASA Technical Reports Server (NTRS)

    Nichol, G. M.; Michels, D. B.; Guy, H. J. B.

    1982-01-01

    A downward-deflecting phase V is often seen following the terminal rise (phase IV) in single-breath washout tests. To investigate the nature of phase V, experiments using simultaneous washouts of N2 and tracer boluses of Ar were performed on eight normal nonsmoking subjects aged 27-41 who exhibited a phase V. Phase V is found to occur in all subjects at expiratory flow rates between 0.1 and 2.0 l/sec shortly after expiration became flow limited. Volumes of both phases IV and V increase with increasing flow rate. The difference between the exhaled volumes at which flow became limited and phase V appeared is shown to be approximately equal to the anatomic dead space. Results support a model of lung emptying in a gravitational field in which flow limitation occurs first in the lower lung regions and then progresses toward the upper regions, causing phase IV. A decrease in the amount of flow from the upper relative to the lower regions after all regions have become flow limited then causes phase V.

  8. [*C]octanoic acid breath test to measure gastric emptying rate of solids.

    PubMed

    Maes, B D; Ghoos, Y F; Rutgeerts, P J; Hiele, M I; Geypens, B; Vantrappen, G

    1994-12-01

    We have developed a breath test to measure solid gastric emptying using a standardized scrambled egg test meal (250 kcal) labeled with [14C]octanoic acid or [13C]octanoic acid. In vitro incubation studies showed that octanoic acid is a reliable marker of the solid phase. The breath test was validated in 36 subjects by simultaneous radioscintigraphic and breath test measurements. Nine healthy volunteers were studied after intravenous administration of 200 mg erythromycin and peroral administration of 30 mg propantheline, respectively. Erythromycin significantly enhanced gastric emptying, while propantheline significantly reduced gastric emptying rates. We conclude that the [*C]octanoic breath test is a promising and reliable test for measuring the gastric emptying rate of solids. PMID:7995200

  9. 13C breath tests in infections and beyond.

    PubMed

    Kurpad, Anura V; Ajami, Alfred; Young, Vernon R

    2002-09-01

    Stable isotope labeled compounds are widely used as diagnostic probes in medicine. These diagnostic stable isotope probes are now being expanded in their scope, to provide precise indications of the presence or absence of etiologically significant change in metabolism due to a specific disease. This concept exploits a labeled tracer probe that is a specifically designed substrate of a "gateway" enzyme in a discrete metabolic pathway, whose turnover can be measured by monitoring unidirectional precursor product mass flow. An example of such a probe is the 13C-urea breath test, where labeled urea is given to patients with H. pylori infection. Another example of this kind of probe is used to study the tripeptide glutathione (glu-cys-gly, GSH), which is the most abundant cellular thiol, and protects cells from the toxic effects of reactive oxygen species. Within the gamma glutamyl cycle, 5-oxoproline (L-pyroglutamic acid) is a metabolite generated during GSH catabolism, and is metabolized to glutamic acid by 5-oxoprolinase. This enzyme can also utilize the substrate L-2-oxothiazolidone-4-carboxylate (OTC), to generate intracellular cysteine, which is beneficial to the cell. Thus, labeled (13C) OTC would, under enzymatic attack yield cysteine and 13CO2, and can thus track the state and capacity of glutathione metabolism. Similarly, stable isotope labeled probes can be used to track the activity of the rate of homocysteine clearance, lymphocyte CD26, and liver CYP (cytochrome P450) enzyme activity. In the future, these applications should be able to titrate, in vivo, the characteristics of various specific enzyme systems in the body and their response to stress or infection as well as to treatment regimes. PMID:12362798

  10. The urea breath test: a non-invasive clinical tool for detecting Helicobacter pylori infection.

    PubMed

    Perri, F; Ghoos, Y; Hiele, M; Andriulli, A; Rutgeerts, P

    1995-03-01

    The urea breath test exploits the urease enzyme of Helicobacter pylori. The hydrolysis of labelled urea releases labelled carbon dioxide that is excreted in the breath. Distribution of urea throughout the stomach prevents sampling errors and allows for semiquantitative assessment of the extent of Helicobacter pylori infection. The urea breath test is very specific and sensitive and can be proposed as the method of choice for detecting Helicobacter pylori infection in ulcer patients before and after eradicating treatment as well as in epidemiological studies. PMID:7579592

  11. (13)C-5-FU breath test current status and future directions: a comprehensive review.

    PubMed

    Ezzeldin, Hany H; Acosta, Edward P; Mattison, Lori K; Fourie, Jeanne; Modak, Anil; Diasio, Robert B

    2009-12-01

    Breath tests (BTs) represent a safe non-invasive alternative strategy that could provide valuable diagnostic information in conditions like fat malabsorption, carbohydrate (lactose and fructose) malabsorption, liver dysfunction, impaired gastric emptying, abnormal small bowel transit time, small intestinal bacterial overgrowth and Helicobacter pylori infection. To date, despite the availability of a number of breath tests, only three have gained approval by the FDA for application in a clinical setting ((13)C-urea breath test for the detection of H. pylori; NO breath test for monitoring asthma and alkane breath test for heart transplant rejection). Unfortunately, none of these tests investigate cancer patients or response to cancer chemotherapy. Several years ago it was realized that the presence of a reliable non-invasive approach could assist in the detection of patients at risk of developing severe life-threatening toxicities prior to the administration of fluoropyrimidines (e.g. 5-FU) or related cancer chemotherapy. 5-FU toxicity results mainly from deficient uracil catabolism. This review discusses the development of a BT that utilizes an orally administered pyrimidine ([2-(13)C]-uracil) which is metabolized via the same catabolic pathway as 5-FU. This ([2-(13)C]-uracil) breath test could provide a valuable addition to the patients' standard of care. PMID:21386199

  12. Steady state respiratory responses to tasks used in Federal testing of self-contained breathing apparatus.

    PubMed

    Kamon, E; Bernard, T; Stein, R

    1975-12-01

    A portion of Title 30, Part II, CFR calls for a Man Test, which is a series of regimens performed with a breathing apparatus. The respiratory responses to the tasks in the Man Test were established on coal miners and students. Based on these responses, the minimal metabolic requirements were derived for the use of breathing apparatuses with a service life of 30 minutes or more. PMID:1211359

  13. (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. PMID:26660654

  14. 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.

  15. 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. PMID:23843422

  16. 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. PMID:24443074

  17. Cholesteryl octanoate breath test. Preliminary studies on a new noninvasive test of human pancreatic exocrine function.

    PubMed

    Cole, S G; Rossi, S; Stern, A; Hofmann, A F

    1987-12-01

    A new breath test for noninvasive assessment of pancreatic exocrine function in humans was developed. The test is based on the hydrolysis of cholesteryl-[1-14C]octanoate by pancreatic carboxyl ester lipase (cholesterol esterase) with subsequent absorption and hepatic metabolism of the liberated octanoate to 14CO2. The rate at which 14CO2 appears in breath appeared to be proportional to the rate of hydrolysis. The substrate is administered as a gum acacia stabilized emulsion of vegetable oil (18 g) containing cholesteryl octanoate (2 g; 4.4 microCi) dispersed in a 500-ml isotonic meal. Tests were performed in 6 healthy volunteers and 11 patients with pancreatic disease with varying degrees of steatorrhea. In healthy subjects, 14CO2 output was rapid with peak output occurring at 60-90 min in all subjects; cumulative output in 4 h averaged 30%. Duplicate studies indicated that the time-course of 14CO2 recovery was reproducible. The pattern of 14CO2 output in patients with pancreatic disease varied widely. Patients without steatorrhea (fecal fat less than or equal to 7 g/day) or with mild steatorrhea (fecal fat 7-11 g/day) had normal or near normal patterns of 14CO2 output, whereas patients with moderate or severe steatorrhea (fecal fat greater than 11 g/day) expired 14CO2 at a rate one-third to one-tenth that of the healthy volunteers. Addition of pancreatic enzyme supplementation to the test meal increased 14CO2 output in 6 of 6 patients with moderate or severe steatorrhea, suggesting that the activity of pancreatic carboxyl ester lipase was rate limiting in these patients. In an additional study in a healthy volunteer, 14CO2 and 13CO2 were measured simultaneously in breath after ingestion of a test meal containing cholesteryl-[1-13C]octanoate and 14C-octanoate. 14CO2 was expired more rapidly than 13CO2, suggesting that hydrolysis of the substrate may also be rate limiting in healthy volunteers. These studies indicate that severe pancreatic exocrine dysfunction can

  18. [The diagnostic value of the aminophenazone breath test in chronic liver diseases].

    PubMed

    Sensing, H; Treutler, J; Haustein, K O; Hüller, G

    1991-09-01

    In 230 patients (90 females, 140 males aged between 20 and 73 years, average age 47.8 years) with and without exception histologically and/or laparoscopically ascertained chronic liver diseases (degenerative damages of liver parenchyma in 45, fatty liver stage I in 28, fatty liver stage II in 36, cholangiohepatitis in 4, chronic persisting hepatitis in 31, chronic active hepatitis in 57 and liver cirrhosis in 59 cases) the incorporation of the aminophenazon breathing test in the so-called laboratory chemical liver spectrum was controlled. The restriction of the microsomal biotransformation established by means of the aminophenazon breathing test behaved parallel to the degree of severity of the disease. The aminophenazon breathing test was performed in the modification after Haustein and Schenker (1985). The largest delays in the decomposition were found in the complete cirrhotic transformation of the liver. The unequivocally pathologic result of the aminophenazon breathing test in severe irreversible damages of the liver parenchyma was confirmed by the formation of correlations with parameters of the conventional laboratory spectrum of the liver. Thus the restriction of the performance of the synthesis of the liver for coagulation factors and albumins was parallel to the loss of function of the mixed functional oxidases. In all patients with chronic liver diseases a connection between the value of the thromboplastin time (Quick's test) and result of the breathing test was found. Positive linear correlation between serum albumin and results of the breathing test could also be proved particularly in the group of the severe chronic inflammatory liver diseases. In chronic fibrosing liver diseases there were positive inverse correlations between gamma-globulin concentration in the serum and thymol turbidity test on the one hand as well as the aminophenazon breathing test on the other. There were no correlations between liver enzyme and aminophenazon breathing test. The

  19. 13C-egg white breath test: a non-invasive test of pancreatic trypsin activity in the small intestine

    PubMed Central

    Evenepoel, P; Hiele, M; Geypens, B; Geboes, K; Rutgeerts, P; Ghoos, Y

    2000-01-01

    BACKGROUND—The recent availability of egg white protein highly enriched with 13C has allowed breath test technology to be adapted for the study of protein digestion and absorption. Pancreatic trypsin is considered to be the key enzyme in the proteolytic cascade.
AIM—To evaluate trypsin activity in the small intestine of healthy volunteers and patients with pancreatic disease by a recently developed 13C-egg white breath test.
METHODS—A total of 48 healthy volunteers and 30 patients with pancreatic disease were studied after ingestion of a test meal consisting of 22 g 13C-labelled egg protein. Breath samples were taken before and after ingestion of the meal and analysed for 13CO2 concentration. Moreover, pancreatic trypsin output after maximal stimulation was measured in 13 patients and nine healthy volunteers.
RESULTS—The six hour cumulative 13CO2 excretion in breath was significantly lower in patients than controls (mean (SEM): 6.23 (0.82)% v 19.16 (0.58)%, p<0.0001). An excellent correlation was found between the six hour cumulative 13CO2 excretion and trypsin activity after maximal pancreatic stimulation.
CONCLUSION—The non-invasive 13C-egg white breath test is promising as an indirect pancreatic proteolytic function test.


Keywords: breath test; pancreatic disease; trypsin; protein; assimilation PMID:10601055

  20. 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.

  1. A 14-day elemental diet is highly effective in normalizing the lactulose breath test.

    PubMed

    Pimentel, Mark; Constantino, Tess; Kong, Yuthana; Bajwa, Meera; Rezaei, Abolghasem; Park, Sandy

    2004-01-01

    Treatment of small intestinal bacterial overgrowth is frustrated by the low efficacy of antibiotics. Elemental diets have been shown to reduce enteric flora. In this study, we evaluate the ability of an elemental diet to normalize the lactulose breath test (LBT) in IBS subjects with abnormal breath test findings. Consecutive subjects with IBS and abnormal LBT suggesting the presence of bacterial overgrowth underwent a 2-week exclusive elemental diet. The diet consisted of Vivonex Plus (Novartis Nutrition Corp., Minneapolis, MN) in a quantity based on individual caloric requirement. On day 15 (prior to solid food), subjects returned for a follow-up breath test and those with an abnormal LBT were continued on the diet for an additional 7 days. The ability of an elemental diet to normalize the LBT was determined for days 15 and 21. A chart review was then conducted to evaluate any clinical benefit 1 month later. Of the 93 subjects available for analysis, 74 (80%) had a normal LBT on day 15 of the elemental diet. When those who continued to day 21 were included, five additional patients normalized the breath test (85%). On chart review, subjects who successfully normalized their breath test had a 66.4 +/- 36.1% improvement in bowel symptoms, compared to 11.9 +/- 22.0% in those who failed to normalize (P < 0.001). An elemental diet is highly effective in normalizing an abnormal LBT in IBS subjects, with a concomitant improvement in clinical symptoms. PMID:14992438

  2. ( 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.

  3. Diagnostic values of Helicobacter pylori diagnostic tests: stool antigen test, urea breath test, rapid urease test, serology and histology*

    PubMed Central

    Kazemi, Shadi; Tavakkoli, Hamid; Habizadeh, Mohamad Reza; Emami, Mohammad Hasan

    2011-01-01

    BACKGROUND: The purpose of this study is to compare validity of 5 diagnostic tests of helicobacter pylori with each other: stool antigen test, urea breath test (UBT), rapid urease test (RUT), serology and histology. METHODS: A total of 94 patients who had indication of endoscopy entered the study. All of the 5 tests were performed for each patient. When the results of at least 2 tests were positive (except serology), Helicobacter pylori infection was considered to be positive. The sensitivity, specificity, positive predictive value, negative predictive value, accuracy and area under receiver operating characteristic (ROC) curve of these 5 tests were determined. RESULTS: The sensitivity, specificity, positive predictive value, negative predictive value, accuracy and area under ROC curve of these 5 tests are as below, respectively. Histology: 89%, 78%, 93%, 91%, 85% and 0.881; RUT: 93%, 75%, 95%, 94%, 86% and 0.831; serology: 50%, 54%, 46%, 61%, 52% and 0.563; stool antigen test: 96%, 83%, 98%, 96%, 91% and 0.897; UBT: 89%, 73%, 92%, 90%, 82% and 0.892. CONCLUSIONS: Stool antigen test is the most accurate test for Helicobacter pylori diagnosis before eradication of these bacteria. PMID:22973378

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. 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.

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

    PubMed

    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

  10. Dosimetry and reproducibility of a capsule-based C-14 urea breath test

    SciTech Connect

    Combs, M.J.; Stubbs, J.B.; Buck, D.A. |

    1995-05-01

    The aims of this study were (1) to determine the excretion of the C-14 and associated radiation dose and (2) to examine the reproducibility of a commercial C-14 urea breath test for H.pylori diagnosis. Tests were performed on twenty consenting volunteers (13M, 7F, 24-48 yr). Breath samples containing 1 mmol CO{sub 2} were obtained at 0,5,10,15,20,25,30 min. and 1,2,3,4,5,6,12, 24 hrs following administration of the 37kBq C-14 urea test capsule. A 24 hr urine collection was performed with each voiding collected separately. A repeat breath test was performed 24 hr after the first. H. pylori positive (HP+) was defined as a 15 minute breath sample >=50 dpm. Total urine excretion was obtained directly. Breath excretion was modeled by estimating the area under the excretion curve and using a constant factor of 884 mmol CO{sub 2}/ hr. Urine and breath excretion data in HP+ and H. pylori-negative (HP-) volunteers were pooled and fit to a monoexponential function thus estimating the cumulative urinary excretion of unmetabolized urea. Previously reported biokinetic models of C-14 urea and bicarbonate were used to estimate radiation doses form each compound. Weighted sums were calculated for each dose estimate using each group`s excretion fraction distribution. Both HP+ and HP- volunteers excreted an average of 73% of the C-14 over the first 24 hr. HP+ excretion was evenly divided between breath (34%) and urine (38%). HP-excretion is almost solely by the urinary pathway. The maximum dose for HP= was to the red marrow (0.0033 mGy) and a maximum of 0.0054 mGy to the urinary bladder wall for HP-. There was no difference between 15 inch breath samples on the two days (t-test, p>0.6). The minimum HP+ result at 15 inch was 270 dpm and the maximum HP- result at 15 inch was 18 dpm, indicating great separation between HP+ and HP- results. This study verifies previous dose estimates using C-14 excretion data. The test is sensitive and reproducible with a low radiation dose.

  11. 13C labelled cholesteryl octanoate breath test for assessing pancreatic exocrine insufficiency

    PubMed Central

    Ventrucci, M; Cipolla, A; Ubalducci, G; Roda, A; Roda, E

    1998-01-01

    Background—A non-invasive test for assessment of fat digestion has been developed based on the intraluminal hydrolysis of cholesteryl-[1-13C]octanoate by pancreatic esterase. 
Aims—To determine the diagnostic performance of this breath test in the assessment of exocrine pancreatic function. 
Methods—The test was performed in 20 healthy controls, 22 patients with chronic pancreatic disease (CPD), four with biliopancreatic diversion (BPD), and 32 with non-pancreatic digestive diseases (NPD); results were compared with those of other tubeless tests (faecal chymotrypsin and fluorescein dilaurate test). 
Results—Hourly recoveries of 13CO2 were significantly lower in CPD when compared with healthy controls or NPD. In patients with CPD with mild to moderate insufficiency, the curve of 13CO2 recovery was similar to that of healthy controls, while in those with severe insufficiency it was flat. In three patients with CPD with severe steatorrhoea, a repeat test after pancreatic enzyme supplementation showed a significant rise in 13CO2 recovery. The four BPD patients had low and delayed 13CO2 recovery. Only eight of the 32 patients with NPD had abnormal breath test results. There was a significant correlation between the results of the breath test and those of faecal chymotrypsin, the fluorescein dilaurate test, and faecal fat measurements. For the diagnosis of pancreatic disease using the three hour cumulative 13CO2 recovery test, the sensitivity was 68.2% and specificity 75.0%; values were similar to those of the other two tubeless pancreatic function tests. In seven healthy controls, nine patients with CPD, and nine with NPD a second breath test was performed using Na-[1-13C]octanoate and a pancreatic function index was calculated as the ratio of 13C recovery obtained in the two tests: at three hours this index was abnormal in eight patients with CPD and in three with NPD. 
Conclusion—The cholesteryl-[1-13C]octanoate breath test can be useful for the

  12. 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. PMID:24443075

  13. 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

  14. 13c-SUCROSE BREATH TEST TO DIFFERENTIATE CONGENITAL SUCRASE-ISOMALTASE DEFICIENCY FROM PANDISACCHARIDASE DEFICIENCY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction: A substrate-paired breath test using 13C-sucrose (S) and 13C-glucose (G) has been developed to assess congenital sucrase-isomaltase deficiency (CSID). The aim was to determine if CSID could be detected without duodenal enzyme assay. Methods: Two patients (1F:1M, aged 1 & 15 yrs) wi...

  15. 13CO2 breath tests in non-invasive hepatological diagnosis

    PubMed Central

    Musialik, Joanna; Kasicka-Jonderko, Anna; Buschhaus, Magdalena

    2015-01-01

    In liver diagnostics, a simple, non-invasive test with high sensitivity and specificity is permanently being sought in order to assess the degree of liver damage. In addition to liver biopsy, algorithms using blood parameters or elastometry are used in clinical practice. However, these methods do not provide information about the true liver reserve, so the liver breath test seem to be a promising diagnostic tool. The basis of this test depends on the ability of particular hepatocyte enzyme systems to metabolise a tested substance labelled with a stable carbon isotope. The kinetics of 13CO2 elimination with expiratory air then permits quantitative assessment of the functional liver reserve and the degree of organ damage. In this paper the most commonly used tests, grouped according to the main metabolic pathways, are described. The usefulness of liver breath tests in specific clinical situations, both as a diagnostic and prognostic tool, is presented. PMID:25960807

  16. Estimation of prevalence of Helicobacter pylori infection in an asymptomatic elderly population comparing [14C] urea breath test and serology.

    PubMed Central

    Newell, D G; Hawtin, P R; Stacey, A R; MacDougall, M H; Ruddle, A C

    1991-01-01

    A non-invasive serological assay devised in this laboratory had a sensitivity and specificity of 100% as determined by culture and confirmed by histology in a group of 47 patients who had undergone endoscopy. The correlation between serology and the non-invasive [14C] breath test was very good. Only one of 24 culture positive patients was, while all 23 culture negative patients were, breath test negative. In a group of 46 healthy elderly persons, however, significant anomalies between serology and breath test were observed. Only 83% of the breath test negative persons were seronegative, while only 68% of the breath test positive persons were seropositive. These results can be explained in terms of age related atrophic gastritis and immune incompetence, causing reduced colonisation and decreased antibody production, respectively. These investigations suggest that non-invasive tests for H pylori infection may not be reliable in the elderly. PMID:2045496

  17. 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

  18. 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

    2015-09-01

    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. PMID:26371034

  19. Anomalous behavior of helium and sulfur hexafluoride during single-breath tests in sustained microgravity.

    PubMed

    Prisk, G K; Lauzon, A M; Verbanck, S; Elliot, A R; Guy, H J; Paiva, M; West, J B

    1996-04-01

    We performed single-breath wash-in tests for He and SF6 in four subjects exposed to 14 days of microgravity (microG) during the Spacelab flight Spacelab Life Sciences-2. Subjects inspired a vital capacity breath of 5% He-1.25% SF6-balance O2 and then exhaled to residual volume at 0.5l/s. The tests were also performed with a 10-s breath hold at the end of inspiration. Measurements were also made with the subjects standing and supine in 1 G. Phase III slope was measured after the dead-space washout and before the onset of airway closure. In all subjects in 1 G, whether standing or supine, phase III slope for SF6 was significantly steeper than that for He. However, in microG, the slopes became the same. Furthermore, after breath holding in microG, the SF6 slopes were significantly flatter than those for He. On return to 1 G, the changes were reversed, and there was no difference between preflight and postflight values. Because most of the phase III slope reflects events occurring in the acinar regions of the lung, the results suggest that microG causes conformational changes in the acini or changes in cardiogenic mixing in the lung periphery, but in either case the mechanism is unclear. PMID:8926236

  20. 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

  1. [DELAYED RESULTS OF ENZYME REPLACEMENT THERAPY, PRESCRIBED BY RESULTS OF 13C-TRIGLYCERIDE BREATH TEST].

    PubMed

    Chernyavskiy, V V; Gvozdetska, L S

    2015-01-01

    Maldigestion persists in most patients with chronic pancreatitis (CP). The objective lipase and amylase insufficiency diagnosis is needed to achieve an adequate clinical response to oral pancreatic enzyme substitution therapy. The novel data is presented in the article about the role of 13C-mixed triglyceride breath test as a tool for exocrine pancreatic insufficiency diagnosis, for evaluating fat malabsorbtion in CP patients. 135 patients were included in the investigation. Delayed results of enzyme replacement therapy were estimated after 1 and 2 year of surveillance. It has been shown, that partial recovery of exocrine pancreatic function is possible, and replacement therapy leads to patients nutritional status improving. Thus 13C-triglyceride breath test could be useful tool in clinical practice for CP diagnosis. The test make it possible to choose the initial pancreatic enzyme dosage and are beneficial during the treatment for pancreatic enzyme dose correction. PMID:26827447

  2. 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

  3. 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. PMID:26978782

  4. 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

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

    PubMed

    Siddiqui, Imran; Ahmed, Sibtain; Abid, Shahab

    2016-08-15

    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

  6. System for routine testing of self-contained and airline breathing equipment.

    PubMed

    McDermott, H J; Hermens, G A

    1980-07-01

    Airline respirators and self-contained breathing equipment are tested in a Shell refinery/petrochemical complex before issue and use of a specially designed system. The pressure-demand devices are tested for: adequate positive pressure inside the facemask during rest and inhalation; sufficient airflow during worker inhalation; and proper operation of the mask exhalation valve. Routine testing after cleaning and maintenance indicates that, although most equipment checks out satisfactorily, the system helps to identify problems that could impair performance. Workers also have added confidence in the respiratory protective equipment because of this testing program. PMID:7415969

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

    PubMed

    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

  8. Application of electrochemical breath test for detection of Helicobacter pylori in screening of Moscow students.

    PubMed

    Kukushkina, I A; Korotkova, O A; Loginov, I A; Vasilieva, E A; Yashina, N V; Anokhina, I V; Kozlov, A V; Tumanova, G M; Tedoradze, R V; Dalin, M V

    2012-01-01

    The incidence of Helicobacter pylori infection is analyzed by the results of screening of first- and fourth-year students of Moscow Institute of Foreign Affairs using HelicoSense Scientific breath test system. Age-related dynamics of the infection in patients examined for the first time has been traced. The data on infection rates in patients after eradication therapy are presented. PMID:22803077

  9. Flight test of multi-pulses vertical laser propulsion in air breathing mode

    NASA Astrophysics Data System (ADS)

    Wen, Ming; Wu, Jie; Wang, Guangyu

    2013-05-01

    The air breathing vertical laser propulsion experiment refers to that in the air breathing mode the light craft under the irradiation of incident laser of vertical direction will turn pulse laser energy into the vertical propulsion thrust of the light craft and continue along the fixed rail upward propulsion flight. It is an important experiment to test the minimum single pulse energy, the optimization degree of light craft structure, and the characteristics of turning the laser energy into the thrust. The experiment is to be conducted dozens of meters in height away the ground generally. The article gives a detailed explanation of the whole process of the air breathing vertical propulsion test, including vertical propulsion light craft design, the connections design, the connections performance test, the frictional resistance detection and the whole process of movement performance test. A vertical propulsion tower was used to conduct the single pulse experiment and multi-pulse performance was predicted with a multiple-pulse thrust measuring system. The impulse coupling coefficient was estimated from fight height. Finally, through the experiments of air breathing vertical laser propulsion, the relation of the movement time and flight height was obtained. In the curve, the mean acceleration of the light craft can arrive to 6m/s2 in the first 20 pulses and the propulsion height can reach 3.5m in 1.12s. After 0.65s, the acceleration of the light craft decreased significantly. The results of the article lay the good foundation for the laser propulsion launch system verification.

  10. 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

  11. 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.

  12. The cut-off criterion for a positive hydrogen breath test in children: a reappraisal.

    PubMed

    Solomons, N W; Barillas, C

    1986-01-01

    Seventy-three preschool children with adequate nutritional status underwent interval-sampling, 3-hour breath-hydrogen carbohydrate absorption tests after consuming either 240 ml of intact milk (containing 12 g of lactose) or the same volume of milk with 90-95% of its lactose prehydrolyzed in vitro (containing less than 1 g lactose, with the remaining sugar as glucose and galactose). Results were examined in a reappraisal of the cut-off criterion for the rise of breath H2 concentration signifying biologically incomplete absorption. If the greater than or equal to 10-ppm criterion advocated by some investigators is used, 83% of our subjects would have been classified as incomplete lactose digesters and 30% would have their tests with the monosaccharide-rich milk classified as positive. With the greater than or equal to 20 ppm criterion used in our laboratory and others, the prevalence of lactose maldigestion in the sample becomes 60% and only 4% of subjects have apparent monosaccharide absorption, 96% having a rise below the cut-off level with prehydrolyzed milk. At least in Guatemalan preschoolers, the 20-ppm criterion for a positive breath H2 test provides a superior specificity-sensitivity balance and more reasonable diagnostic conclusions. PMID:3794911

  13. 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

    2015-12-01

    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

  14. Measurement of fat digestion in early life using a stable isotope breath test.

    PubMed Central

    McClean, P; Harding, M; Coward, W A; Green, M R; Weaver, L T

    1993-01-01

    13C breath tests are a safe, non-invasive way of assessing nutrient digestion and absorption that can be used repeatedly in infancy and childhood. The aim of this study was to assess their value for measuring fat digestion in infants and young children with cystic fibrosis, and healthy controls whose pancreatic exocrine function is immature, and to monitor pancreatic enzyme supplementation. Six infants with cystic fibrosis (aged 10-18 months) and nine healthy controls (aged 6-19 months) were studied. After an overnight fast each child ingested 7.5 mg/kg 13C trioctanoin (99 atom % excess) followed by a known volume of milk. Breath samples were collected before and at 30 minute intervals thereafter for five hours. The 13C enrichment of expired carbon dioxide was measured by gas isotope ratio mass spectrometry. The mean (SD) percentage dose recovery of 13C was 13.5 (5.3) for the cystic fibrosis group and 24.2 (6.7) for the healthy controls. When those with cystic fibrosis were studied after supplementary pancreatic enzymes, the mean percentage dose recovery rose to 17.1 (6.9). Total intraluminal lipolysis was diminished by 44% in young children with cystic fibrosis. Pancreatic enzyme supplements improved digestion by 27%. The 13C trioctanoin breath test was effective in detecting fat maldigestion and can be used to measure the benefits of enzyme supplements in early life. PMID:8215547

  15. 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

  16. Diagnosing lactose malabsorption in children: difficulties in interpreting hydrogen breath test results.

    PubMed

    Ruzsanyi, Veronika; Heinz-Erian, Peter; Entenmann, Andreas; Karall, Daniela; Müller, Thomas; Schimkowitsch, Alexander; Amann, Anton; Scholl-Bürgi, Sabine

    2016-03-01

    Lactose malabsorption (LM) is caused by insufficient enzymatic degradation of the disaccharide by intestinal lactase. Although hydrogen (H2) breath tests (HBTs) are routinely applied to diagnose LM, false-negative results are not uncommon. Thirty-two pediatric patients (19 females, 13 males) were included in this prospective study. After oral lactose administration (1 g kg(-1) bodyweight to a maximum of 25 g), breath H2 was measured by electrochemical detection. HBT was considered positive if H2 concentration exceeded an increase of  ⩾20 ppm from baseline. In addition to H2, exhaled methane (CH4), blood glucose concentrations and clinical symptoms (flatulence, abdominal pain, diarrhea) were monitored. A positive HBT indicating LM was found in 12/32 (37.5%) patients. Only five (41.7%, 5/12) of these had clinical symptoms during HBT indicating lactose intolerance (LI). Decreased blood glucose concentration increments (⩽20 mg dL(-1) (⩽1.1 mmol L(-1))) were found in 3/5 of these patients. CH4 concentrations  ⩾10 ppm at any time during the test were observed in 5/32 (15.6%) patients and in 9/32 (28.1%) between 1 ppm and 9 ppm above baseline after lactose ingestion. In patients with positive HBT 10/12 (83.3%) showed elevated CH4 (>1 ppm) above baseline in breath gas, whereas in patients with negative HBT this figure was only 4/17 (23.5%). In addition to determining H2 in exhaled air, documentation of clinical symptoms, measurement of blood glucose and breath CH4 concentrations may be helpful in deciding whether in a given case an HBT correctly identifies patients with clinically relevant LM. PMID:26934035

  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, 2013 CFR

    2013-10-01

    ... 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... breath has been obtained. (d) Show the employee the displayed test result. (e) If the device is one...

  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, 2011 CFR

    2011-10-01

    ... 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... breath has been obtained. (d) Show the employee the displayed test result. (e) If the device is one...

  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, 2014 CFR

    2014-10-01

    ... 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... breath has been obtained. (d) Show the employee the displayed test result. (e) If the device is one...

  20. 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...-evidential breath ASD? As the BAT or STT, you must take the following steps: (a) Select, or allow the... breath has been obtained. (d) Show the employee the displayed test result. (e) If the device is one...

  1. 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

    ... 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... breath has been obtained. (d) Show the employee the displayed test result. (e) If the device is one...

  2. Assessment of liver function in dogs using the 13C-galactose breath test.

    PubMed

    Silva, S; Wyse, C A; Goodfellow, M R; Yam, P S; Preston, T; Papasouliotis, K; Hall, E J

    2010-08-01

    The aim of this study was to evaluate the application of the 13C-galactose breath test (13C-GBT) in assessing canine liver function by applying it to a group of healthy dogs, and to a group with clinicopathological evidence of liver dysfunction. Breath samples were collected 30 min before ingestion of 13C-galactose, and then at regular intervals thereafter for 6 h. The proportion of 13CO2/12CO2 in the breath samples was measured by isotope-ratio mass spectrometry. There was no significant difference in recovery of 13CO2 in the diseased group, compared to the healthy controls, but there was considerable inter-subject variation in both groups, possibly due to differences in the rate of gastric emptying, which could preclude detection of alterations in hepatic metabolism of galactose. The results of this study do not support the application of the 13C-GBT for assessment of canine liver function. PMID:19546016

  3. 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

  4. Cost-effectiveness of the Carbon-13 Urea Breath Test for the Detection of Helicobacter Pylori

    PubMed Central

    Masucci, L; Blackhouse, G; Goeree, R

    2013-01-01

    Objectives This analysis aimed to evaluate the cost-effectiveness of various testing strategies for Helicobacter pylori in patients with uninvestigated dyspepsia and to calculate the budgetary impact of these tests for the province of Ontario. Data Sources Data on the sensitivity and specificity were obtained from the clinical evidence-based analysis. Resource items were obtained from expert opinion, and costs were applied on the basis of published sources as well as expert opinion. Review Methods A decision analytic model was constructed to compare the costs and outcomes (false-positive results, false-negative results, and misdiagnoses avoided) of the carbon-13 (13C) urea breath test (UBT), enzyme-linked immunosorbent assay (ELISA) serology test, and a 2-step strategy of an ELISA serology test and a confirmatory 13C UBT based on the sensitivity and specificity of the tests and prevalence estimates. Results The 2-step strategy is more costly and more effective than the ELISA serology test and results in $210 per misdiagnosis case avoided. The 13C UBT is dominated by the 2-step strategy, i.e., it is more costly and less effective. The budget impact analysis indicates that it will cost $7.9 million more to test a volume of 129,307 patients with the 13C UBT than with ELISA serology, and $4.7 million more to test these patients with the 2-step strategy. Limitations The clinical studies that were pooled varied in the technique used to perform the breath test and in reference standards used to make comparisons with the breath test. However, these parameters were varied in a sensitivity analysis. The economic model was designed to consider intermediate outcomes only (i.e., misdiagnosed cases) and was not a complete model with final patient outcomes (e.g., quality-adjusted life years). Conclusions Results indicate that the 2-step strategy could be economically attractive for the testing of H. pylori. However, testing with the 2-step strategy will cost the Ministry of

  5. Use of liver breath tests to assess severity of nonalcoholic fatty liver disease.

    PubMed

    Furnari, Manuele; Savarino, Vincenzo; Giannini, Edoardo G

    2014-01-01

    As the prevalence of obesity and insulin-resistance continues to increase in the general population, nonalcoholic fatty liver disease (NAFLD) has reached epidemic proportions, thus becoming one of the leading causes of chronic liver disease worldwide. It may present as simple steatosis (NAFL) or steatohepatitis (NASH), which in turn may develop fibrosis and ultimately cirrhosis. Conventional biochemical liver test and radiological investigations are not able to provide reliable information on liver functional reserve, and liver biopsy remains the gold standard to stage NAFLD, differentiate simple steatosis from NASH, and grade fibrosis. However, liver biopsy has some limitations, and is not preferred by patients due to its invasiveness. Thus, non-invasive assessment of disease stage by using liver breath tests - which are based on hepatic clearance of non-radioactive stable (13)C-labelled drugs - may be of interest to stage disease and assess patients prognosis due to good accuracy and repeatability. These substrates are orally administered and are cleaved by enzymes specifically located in the liver thus reflecting either the microsomal, cytosolic, or mitochondrial functions. (13)C-Breath Tests have been initially oriented to differentiate broad categories of patients and more recently to refine stage differentiation in patients with early stages of liver disease. In NAFLD patients, (13)C-BTs were able to distinguish simple steatosis from NASH and had good correlation with both histological fibrosis stage and biochemical markers of fibrogenesis. Although promising results have been achieved in this field, their use in clinical practice is still restricted to a specialized niche. However, concordant data from literature conferred to (13)C-Breath Tests a potential role in providing punctual and longitudinal evaluation of patients, identifying those patients where liver biopsy may selectively be performed to stage disease, monitoring and predicting therapeutic

  6. Posttreatment 13C-Urea Breath Test Is Predictive of Antimicrobial Resistance to H. pylori After Failed Therapy

    PubMed Central

    Kao, Ai-Wen; Cheng, Hsiu-Chi; Sheu, Bor-Shyang; Lin, Ching-Yih; Sheu, Ming-Jen; Yang, Hsiao-Bai; Wu, Jiunn-Jong

    2005-01-01

    OBJECTIVE We tested whether a 13C-urea breath test can predict antimicrobial resistance of Helicobacter pylori (H. pylori). METHODS Seventy patients who had failed triple eradication therapy and 108 untreated H. pylori-infected patients were given a 13C-urea breath test, endoscopy for culture of H. pylori, and assessment of clarithromycin resistance. The patients who had failed triple therapy then received 1 week of quadruple therapy to eradicate residual H. pylori. RESULTS The posttreatment value of the 13C-urea breath test expressed as excessive δ13CO2 per ml (ECR) was higher in patients with residual H. pylori with clarithromycin resistance than in those without (23.8 vs 10.6; P <.0001). With a cutoff of ECR >or≤15, the 13C-urea breath test was 88.6% sensitive and 88.9% specific in predicting clarithromycin resistance of residual H. pylori. The H. pylori eradication rate of the rescue regimen was higher for patients with a posttreatment ECR of the 13C-urea breath test ≤ 15 than for those with a value >15 (93.8% vs 73.3%; P <.05). In contrast, in treatment-naive H. pylori-infected patients, the pretreatment value of the 13C-urea breath test did not differ between patients infected with clarithromycin-resistant or-sensitive isolates (P >.05). CONCLUSION The posttreatment value of the 13C-urea breath test is predictive of clarithromycin resistance in residual H. pylori after failed triple therapy and predicts efficacy of the rescue regimen. The value of the noninvasive test is promising for primary care physicians who need to select a rescue regimen without invasive H. pylori culture. PMID:15836546

  7. Simple 13C-urea breath test with infra-red spectrophotometer.

    PubMed

    Taniguchi, Y; Kimura, K; Sohara, H; Shirasaki, A; Kawada, H; Satoh, K; Kihira, K; Wang, X M; Takimoto, T; Goto, Y; Takatori, K; Iida, K; Kajiwara, M

    1996-11-01

    When mass spectrophotometric analysis is used for the 13C-urea breath test to assess H. pylori infection, it is costly, complicated, and time-consuming. To overcome these disadvantages, we utilized an infra-red spectrophotometer as a substitute for the mass spectrophotometer. A total of 153 patients (181 tests) analyzed with peptic ulcers or non-ulcer dyspepsia were investigated. Breath samples were collected 15 min after ingestion of 13C-urea (100 mg in 30 ml water). An infra-red spectrophotometer was used to determine the concentration of 13CO2 in the expirate. The 13CO2/12CO2 ratio was also measured by mass spectrophotometry to compare results with those of infra-red spectrophotometric analysis. Direct detection of H. pylori was qualified in biopsy specimens. Of the 181 biopsies, 138 were positive for H. pylori infection and 43 were negative. With the urea breath test, the mean value in the positive group was significantly higher than that in the negative group (0.062 +/- 0.044 vs 0.011 +/- 0.014, respectively). The cut-off level, 0.01, was determined as delta 13C atom %. The sensitivity of infra-red spectrophotometry was 97.8% (135/138) and specificity was 74.4% (32/43). There was an extremely high coefficient of correlation (r = 0.996) between mass and infra-red photometric analysis. Infra-red spectrometry appears to have great potential not only for diagnosing H. pylori infection but also for assessing treatment results. Its advantages include technical simplicity, cost-effectiveness, and high accuracy. PMID:8959516

  8. 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:...

  9. 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

  10. 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.

  11. 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.

  12. 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. PMID:24443068

  13. An optimized 13C-urea breath test for the diagnosis of H pylori infection

    PubMed Central

    Campuzano-Maya, Germán

    2007-01-01

    AIM: To validate an optimized 13C-urea breath test (13C-UBT) protocol for the diagnosis of H pylori infection that is cost-efficient and maintains excellent diagnostic accuracy. METHODS: 70 healthy volunteers were tested with two simplified 13C-UBT protocols, with test meal (Protocol 2) and without test meal (Protocol 1). Breath samples were collected at 10, 20 and 30 min after ingestion of 50 mg 13C-urea dissolved in 10 mL of water, taken as a single swallow, followed by 200 mL of water (pH 6.0) and a circular motion around the waistline to homogenize the urea solution. Performance of both protocols was analyzed at various cut-off values. Results were validated against the European protocol. RESULTS: According to the reference protocol, 65.7% individuals were positive for H pylori infection and 34.3% were negative. There were no significant differences in the ability of both protocols to correctly identify positive and negative H pylori individuals. However, only Protocol 1 with no test meal achieved accuracy, sensitivity, specificity, positive and negative predictive values of 100%. The highest values achieved by Protocol 2 were 98.57%, 97.83%, 100%, 100% and 100%, respectively. CONCLUSION: A 10 min, 50 mg 13C-UBT with no test meal using a cut-off value of 2-2.5 is a highly accurate test for the diagnosis of H pylori infection at a reduced cost. PMID:17907288

  14. Reporter Phage and Breath Tests: Emerging Phenotypic Assays for Diagnosing Active Tuberculosis, Antibiotic Resistance, and Treatment Efficacy

    PubMed Central

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

    2011-01-01

    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. PMID:21996696

  15. 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.

  16. False-positive breath-alcohol test after a ketogenic diet.

    PubMed

    Jones, A W; Rössner, S

    2007-03-01

    A 59-year-old man undergoing weight loss with very low calorie diets (VLCD) attempted to drive a car, which was fitted with an alcohol ignition interlock device, but the vehicle failed to start. Because the man was a teetotaller, he was surprised and upset by this result. VLCD treatment leads to ketonemia with high concentrations of acetone, acetoacetate and beta-hydroxybutyrate in the blood. The interlock device determines alcohol (ethanol) in breath by electrochemical oxidation, but acetone does not undergo oxidation with this detector. However, under certain circumstances acetone is reduced in the body to isopropanol by hepatic alcohol dehydrogenase (ADH). The ignition interlock device responds to other alcohols (e.g. methanol, n-propanol and isopropanol), which therefore explains the false-positive result. This 'side effect' of ketogenic diets needs further discussion by authorities when people engaged in safety-sensitive work (e.g. bus drivers and airline pilots) submit to random breath-alcohol tests. PMID:16894360

  17. Nitric oxide breath testing by tunable-diode laser absorption spectroscopy: application in monitoring respiratory inflammation

    NASA Astrophysics Data System (ADS)

    Roller, Chad; Namjou, Khosrow; Jeffers, James D.; Camp, Mark; Mock, Adam; McCann, Patrick J.; Grego, Joe

    2002-10-01

    We used a high-resolution mid-IR tunable-laser absorption spectroscopy (TLAS) system with a single IV-VI laser operating near 5.2 mum to measure the level of exhaled nitric oxide (eNO) in human breath. A method of internal calibration using simultaneous eNO and exhaled CO2 measurements eliminated the need for system calibration with gas standards. The results observed from internally calibrating the instrument for eNO measurements were compared with measurements of eNO calibrated to gas standards and were found to be similar. Various parameters of the TLAS system for eNO breath testing were examined and include gas cell pressure, exhalation time, and ambient NO concentrations. A reduction in eNO from elevated concentrations (approx44 parts in 109) to near-normal levels (<20 parts in 109) from an asthmatic patient was observed after the patient had received treatment with an inhaled glucocorticoid anti-inflammatory medication. Such measurements can help in evaluating airway inflammation and in monitoring the effectiveness of anti-inflammatory therapies.

  18. 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.

  19. 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

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

    NASA Astrophysics Data System (ADS)

    Metzger, Robert Lawrence

    The solubility of inhaled radionuclides in the human lung is an important characteristic of the compounds needed to perform internal dosimetry assessments for exposed workers. A solubility testing method for uranium and 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 (PERALSsp°ler ) 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 Usb3Osb8. This makes it possible to characterize solubility profiles in every section of operating facilities where airborne nuclides are found using common breathing zone air samples. The new method was evaluated by analyzing uranium compounds from two uranium mills whose product had been previously analyzed by in vitro solubility testing in the laboratory and in vivo solubility testing in rodents. The new technique compared well with the in vivo rodent solubility profiles. The method was then used to evaluate the solubility profiles in all process sections of an operating in situ uranium plant using breathing zone and area air samples collected during routine

  1. 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 permitted under these regulations? 40.277 Section 40.277 Transportation Office of the Secretary of Transportation PROCEDURES FOR TRANSPORTATION WORKPLACE DRUG AND ALCOHOL TESTING PROGRAMS Problems in...

  2. 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 permitted under these regulations? 40.277 Section 40.277 Transportation Office of the Secretary of Transportation PROCEDURES FOR TRANSPORTATION WORKPLACE DRUG AND ALCOHOL TESTING PROGRAMS Problems in...

  3. 13C-phenylalanine breath test detects altered phenylalanine kinetics in schizophrenia patients.

    PubMed

    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-(13)C]phenylalanine breath test ((13)C-PBT). The subjects were 20 chronically medicated schizophrenia patients (DSM-IV) and the same number of age- and sex-matched controls. (13)C-phenylalanine (99 atom% (13)C; 100 mg) was administered orally and the breath (13)CO(2) /(12)CO(2) ratio was monitored for 120 min. The possible effect of antipsychotic medication (risperidone (RPD) or haloperidol (HPD) treatment for 21 days) on (13)C-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 Δ(13)CO(2) (‰) 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 Δ(13)CO(2) 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 (13)C-PBT indices in rats. Our results suggest that (13)C-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

  4. (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.

  5. 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... Alcohol Screening Tests § 40.245 What is the procedure for an alcohol screening test using a saliva ASD or a breath tube ASD? (a) As the STT or BAT, you must take the following steps when using the...

  6. 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... Alcohol Screening Tests § 40.245 What is the procedure for an alcohol screening test using a saliva ASD or a breath tube ASD? (a) As the STT or BAT, you must take the following steps when using the...

  7. 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... Alcohol Screening Tests § 40.245 What is the procedure for an alcohol screening test using a saliva ASD or a breath tube ASD? (a) As the STT or BAT, you must take the following steps when using the...

  8. Diagnosis of Helicobacter pylori by carbon-13 urea breath test using a portable mass spectrometer

    PubMed Central

    Sreekumar, J; France, N; Taylor, S; Matthews, T; Turner, P; Bliss, P; Watson, AJM

    2015-01-01

    Context: In the non-invasive detection of markers of disease, mass spectrometry is able to detect small quantities of volatile markers in exhaled air. However, the problem of size, expense and immobility of conventional mass spectrometry equipment has restricted its use. Now, a smaller, less expensive, portable quadrupole mass spectrometer system has been developed. Helicobacter pylori has been implicated in the development of chronic gastritis, gastric and duodenal ulcers and gastric cancer. Objectives: To compare the results obtained from the presence of H. pylori by a carbon-13 urea test using a portable quadrupole mass spectrometer system with those from a fixed mass spectrometer in a hospital-based clinical trial. Methods: Following ethical approval, 45 patients attending a gastroenterology clinic at the Royal Liverpool University Hospital exhaled a breath sample into a Tedlar gas sampling bag. They then drank an orange juice containing urea radiolabelled with carbon and 30 min later gave a second breath sample. The carbon-13 content of both samples was measured using both quadrupole mass spectrometer systems. If the post-drink level exceeded the pre-drink level by 3% or more, a positive diagnosis for the presence of H. pylori was made. Results: The findings were compared to the results using conventional isotope ratio mass spectrometry using a laboratory-based magnetic sector instrument off-site. The results showed agreement in 39 of the 45 patients. Conclusions: This study suggests that a portable quadrupole mass spectrometer is a potential alternative to the conventional centralised testing equipment. Future development of the portable quadrupole mass spectrometer to reduce further its size and cost is indicated, together with further work to validate this new equipment and to enhance its use in mass spectrometry diagnosis of other medical conditions. PMID:26770764

  9. Exocrine pancreatic insufficiency: accuracy and clinical value of the uniformly labelled 13C-Hiolein breath test.

    PubMed Central

    Lembcke, B; Braden, B; Caspary, W F

    1996-01-01

    BACKGROUND AND AIMS: The 13C-Hiolein breath test (98% [U-13C] labelled long chain triglyceride mixture (highly labelled triolein) was evaluated as a non-invasive, non-radioactive test for exocrine pancreatic insufficiency. Accuracy and clinical validity were examined with reference to both the secretin pancreozymin test and faecal fat analysis. METHODS: A secretin pancreozymin test and faecal fat analysis were performed in 46 patients, 30 with exocrine pancreatic insufficiency and 16 with normal pancreatic function. In all of these patients and in seven healthy volunteers (controls), a 13C-Hiolein breath test was performed using 2 mg/kg [U-13C] labelled Hiolein with a standard risk snack (1.5 g/kg; 25% fat). 13CO2/12CO2 enrichment in the exhaled breath was measured by isotope ratio mass spectrometry. RESULTS: In patients with pancreatic steatorrhoea the 13CO2 response was below the 95% confidence interval of 13CO2 exhalation in the controls. These responses were also diminished (p < 0.001) compared with patients with impaired lipase output but normal fat excretion and with disease as well as healthy controls. There was a linear correlation between stimulated lipase output and the ratio of lipase output/13CO2 response (r = 0.95). Among the 40 patients in whom direct pancreatic function testing was clinically indicated, the sensitivity of the 13C-Hiolein test for detecting steatorrhoea was 91.7%, with a specificity of 85.7%. CONCLUSIONS: In patients with pancreatic disease the 13C-Hiolein breath test reflects impaired lipase output and indicates decompensated lipolysis. The 13C-Hiolein breath test is a convenient alternative to faecal fat analysis. PMID:9026480

  10. Capsule 13C-urea breath test for the diagnosis of Helicobacter pylori infection

    PubMed Central

    Peng, Nan-Jing; Lai, Kwok-Hung; Liu, Ren-Shyan; Lee, Shui-Cheng; Tsay, Daw-Guey; Lo, Ching-Chu; Tseng, Huei-Hwa; Huang, Wen-Keui; Lo, Gin-Ho; Hsu, Ping-I

    2005-01-01

    AIM: To compare the accuracy of capsule 13C-urea breath test (UBT) with conventional invasive methods for the diagnosis of Helicobacter pylori infection. METHODS: One hundred patients received CLO test, histological examination, culture and 100- or 50-mg capsule UBT for the diagnosis of H pylori infection. H pylori infection was defined as those with positive culture or positive results from both histology and CLO test. RESULTS: Both the sensitivity and specificity of the 100-mg capsule UBT (n = 50) were 100%. The sensitivity and specificity of the 50-mg capsule UBT (n = 50) were 96.4 and 100%, respectively. Taken together, the accuracy of capsule UBT (n = 100) was higher than that of CLO test, histology and culture (100% vs 92%, 91% and 89%, respectively; P = 0.035, 0.018 and 0.005, respectively). Our data showed that the optimal timing of sampling for 100- and 50-mg capsule UBT was 15-30 and 6-15 min, respectively. CONCLUSION: Capsule UBT has a higher accuracy compared with biopsy-based tests. It is an ideal method for the diagnosis of H pylori infection. PMID:15761976

  11. Comparison of an enzyme immunoassay for the detection of Helicobacter pylori antigens in the faeces with the urea breath test

    PubMed Central

    Shepherd, A.; Williams, C.; Doherty, C.; Hossack, M.; Preston, T.; McColl, K.; Weaver, L.

    2000-01-01

    BACKGROUND—Current diagnostic tests for Helicobacter pylori are invasive (endoscopy) or indirect (urea breath test, serology).
AIMS—To evaluate a new enzyme immunoassay (EIA) which detects H pylori antigens in faeces, by comparing its sensitivity and specificity in children with the 13C urea breath test (UBT).
METHODS—A total of 119 children underwent a UBT and provided a faecal sample for antigen testing within seven days. After an overnight fast each child provided a pretest breath sample, and samples at 30 and 40 minutes after ingestion of 100 mg 13C labelled urea. 13C enrichment of breath was measured by isotope ratio mass spectrometry. Faeces were stored at −70°C until antigen testing, using the EIA. Samples were read spectrophotometrically at 450 nm and results were interpreted using recommended cut offs of optical density <0.14 as negative, ⩾0.16 as positive, with ⩾0.14 and <0.16 representing equivocal results. Sensitivity and specificity were calculated using the manufacturer's cut off compared with UBT.
RESULTS—Sensitivity and specificity were 88% and 82%, respectively. Negative and positive predictive values were 97% and 58%.
CONCLUSIONS—The EIA is an alternative, non-invasive, and easy to use method for the detection of H pylori in children. Its high negative predictive value suggests a role in screening out uninfected children.

 PMID:10952653

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

    PubMed Central

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

    2015-01-01

    AIM: To investigate whether posture affects the accuracy of 13C-urea breath test (13C-UBT) for Helicobacter pylori (H. pylori) detection in partial gastrectomy patients. METHODS: 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 13C-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 13C-UBT: 75 mg of 13C-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‰. RESULTS: 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

  13. Dynamic carbon 13 breath tests for the study of liver function and gastric emptying.

    PubMed

    Bonfrate, Leonilde; Grattagliano, Ignazio; Palasciano, Giuseppe; Portincasa, Piero

    2015-02-01

    In gastroenterological practice, breath tests (BTs) are diagnostic tools used for indirect, non-invasive assessment of several pathophysiological metabolic processes, by monitoring the appearance in breath of a metabolite of a specific substrate. Labelled substrates originally employed radioactive carbon 14 ((14)C) and, more recently, the stable carbon 13 isotope ((13)C) has been introduced to label specific substrates. The ingested (13)C-substrate is metabolized, and exhaled (13)CO2 is measured by mass spectrometry or infrared spectroscopy. Some (13)C-BTs evaluate specific (microsomal, cytosolic, and mitochondrial) hepatic metabolic pathways and can be employed in liver diseases (i.e. simple liver steatosis, non-alcoholic steato-hepatitis, liver fibrosis, cirrhosis, hepatocellular carcinoma, drug and alcohol effects). Another field of clinical application for (13)C-BTs is the assessment of gastric emptying kinetics in response to liquids ((13)C-acetate) or solids ((13)C-octanoic acid in egg yolk or in a pre-packed muffin or the (13)C-Spirulina platensis given with a meal or a biscuit). Studies have shown that (13)C-BTs, used for gastric emptying studies, yield results that are comparable to scintigraphy and can be useful in detecting either delayed- (gastroparesis) or accelerated gastric emptying or changes of gastric kinetics due to pharmacological effects. Thus, (13)C-BTs represent an indirect, cost-effective and easy method of evaluating dynamic liver function and gastric kinetics in health and disease, and several other potential applications are being studied. PMID:25339354

  14. Dynamic carbon 13 breath tests for the study of liver function and gastric emptying

    PubMed Central

    Bonfrate, Leonilde; Grattagliano, Ignazio; Palasciano, Giuseppe; Portincasa, Piero

    2015-01-01

    In gastroenterological practice, breath tests (BTs) are diagnostic tools used for indirect, non-invasive assessment of several pathophysiological metabolic processes, by monitoring the appearance in breath of a metabolite of a specific substrate. Labelled substrates originally employed radioactive carbon 14 (14C) and, more recently, the stable carbon 13 isotope (13C) has been introduced to label specific substrates. The ingested 13C-substrate is metabolized, and exhaled 13CO2 is measured by mass spectrometry or infrared spectroscopy. Some 13C-BTs evaluate specific (microsomal, cytosolic, and mitochondrial) hepatic metabolic pathways and can be employed in liver diseases (i.e. simple liver steatosis, non-alcoholic steato-hepatitis, liver fibrosis, cirrhosis, hepatocellular carcinoma, drug and alcohol effects). Another field of clinical application for 13C-BTs is the assessment of gastric emptying kinetics in response to liquids (13C-acetate) or solids (13C-octanoic acid in egg yolk or in a pre-packed muffin or the 13C-Spirulina platensis given with a meal or a biscuit). Studies have shown that 13C-BTs, used for gastric emptying studies, yield results that are comparable to scintigraphy and can be useful in detecting either delayed- (gastroparesis) or accelerated gastric emptying or changes of gastric kinetics due to pharmacological effects. Thus, 13C-BTs represent an indirect, cost-effective and easy method of evaluating dynamic liver function and gastric kinetics in health and disease, and several other potential applications are being studied. PMID:25339354

  15. Test plan 241-C-103 natural breathing characteristics evaluation using the ultra sensitive flowmeter

    SciTech Connect

    Hertelendy, N.A.

    1995-02-13

    To facilitate the reduction of worker exposure to hazardous fumes and vapors, it is imperative to characterize and measure flows out of waste tanks that breathe due to atmospheric pressure changes. These measurements will lead to a better understanding of how these tanks breathe and thus will aid in better worker exposure control at lower cost.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  18. 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.

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

    PubMed Central

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

    2015-01-01

    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 13C/H2 lactose breath test that measures breath 13CO2 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 13C/H2 lactose breath tests to assess the impact on the diagnostic accuracy of measuring breath CH4 in addition to H2 and 13CO2. Based on the 13C/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 13C/H2 breath test to identify methanogenic subjects with lactose malabsorption or SIBO. PMID:26371034

  20. Gender-associated differences in urea breath test for Helicobacter pylori infection referrals and results among dyspeptic patients

    PubMed Central

    Moshkowitz, Menachem; Horowitz, Noya; Beit-Or, Anat; Halpern, Zamir; Santo, Erwin

    2012-01-01

    AIM: To verify whether there is a gender difference in the 13C-urea breath test results in a large cohort. METHODS: The test results of dyspeptic patients referred for 13C-urea breath testing between January and December, 2007 were evaluated. Testing was carried out at the health insurance organization branches and evaluated at a central laboratory in Israel. RESULTS: Of a total of 28 746 test results, 18 122 (63.04%) were from females and 10 624 (36.95%) from males. Overall, 10 188 (35.4%) results [expressed as delta over baseline (DOB)] were positive (DOB 13C > 5), 18,326 (63.7%) were negative (DOB 13C < 3.5) and 232 (0.8%) were borderline (DOB 13C 3.5-5). There was a significant difference between the total positive rate among females and males (34.8% vs 37.2%, respectively, P = 0.0003). The mean test value was increased by approximately 10 units for females compared to males (P < 0.01) and this difference was consistent for all age groups (i.e., between 10-80 years of age, P < 0.01). CONCLUSION: More females were referred to 13C-urea breath testing. More males had positive results. The mean test values were significantly higher among females of all age groups, possibly representing an increased bacterial load among females and suggesting gender-associated differences in Helicobacter pylori host interactions. PMID:22737592

  1. Applicability of a short/rapid 13C-urea breath test for Helicobacter pylori: retrospective multicenter chart review study

    PubMed Central

    2012-01-01

    Background Carbon labeled urea breath tests usually entail a two point sampling with a 20 to 30-minute gap. Our aim was to evaluate the duration of time needed for diagnosing Helicobacter pylori by the BreathID® System. Methods This is a retrospective multicenter chart review study. Test location, date, delta over baseline, and duration of the entire test were recorded. Consecutively 13C urea breath tests results were extracted from the files over a nine year period. Results Of the 12,791 tests results, 35.1% were positively diagnosed and only 0.1% were inconclusive. A statistically significant difference in prevalence among the countries was found: Germany showing the lowest, 13.3%, and Israel the highest, 44.1%. Significant differences were found in time to diagnosis: a positive diagnosis had the shortest and an inconclusive result had the longest. Overall test duration averaged 15.1 minutes in Germany versus approximately 13 minutes in other countries. Diagnosis was achieved after approximately 9 minutes in Israel, Italy and Switzerland, but after 10 on average in the others. The mean delta over baseline value for a negative diagnosis was 1.03 ± 0.86, (range, 0.9 - 5), versus 20.2 ± 18.9, (range, 5.1 - 159.4) for a positive one. Conclusions The BreathID® System used in diagnosing Helicobacter pylori can safely shorten test duration on average of 10-13 minutes without any loss of sensitivity or specificity and with no test lasting more than 21 minutes. PMID:22260296

  2. Accuracy of urea breath test in Helicobacter pylori infection: Meta-analysis

    PubMed Central

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

    2015-01-01

    AIM: 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. METHODS: 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). RESULTS: 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. CONCLUSION: 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. PMID:25632206

  3. 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

  4. Small Intestinal Bacterial Overgrowth Diagnosed by Glucose Hydrogen Breath Test in Post-cholecystectomy Patients

    PubMed Central

    Sung, Hea Jung; Paik, Chang-Nyol; Chung, Woo Chul; Lee, Kang-Moon; Yang, Jin-Mo; Choi, Myung-Gyu

    2015-01-01

    Background/Aims Patients undergoing cholecystectomy may have small intestinal bacterial overgrowth (SIBO). We investigated the prevalence and characteristics of SIBO in patients with intestinal symptoms following cholecystectomy. Methods Sixty-two patients following cholecystectomy, 145 with functional gastrointestinal diseases (FGIDs), and 30 healthy controls undergoing hydrogen (H2)-methane (CH4) glucose breath test (GBT) were included in the study. Before performing GBT, all patients were interrogated using bowel symptom questionnaire. The positivity to GBT indicating the presence of SIBO, gas types and bowel symptoms were surveyed. Results Post-cholecystectomy patients more often had SIBO as evidenced by a positive (+) GBT than those with FGID and controls (29/62, 46.8% vs 38/145, 26.2% vs 4/30, 13.3%, respectively; P = 0.010). In the gas types, the GBT (H2) + post-cholecystectomy patients was significantly higher than those in FGIDs patients (P = 0.017). Especially, positivity to fasting GBT (H2) among the GBT (H2)+ post-cholecystectomy patients was high, as diagnosed by elevated fasting H2 level. The GBT+ group had higher symptom scores of significance or tendency in abdominal discomfort, bloating, chest discomfort, early satiety, nausea, and tenesmus than those of the GBT negative group. The status of cholecystectomy was the only significant independent factor for predicting SIBO. Conclusions The SIBO with high levels of baseline H2 might be the important etiologic factor of upper GI symptoms for post-cholecystectomy patients. PMID:26351251

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

    PubMed

    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

  6. Erythromycin breath test as an assay of glucocorticoid-inducible liver cytochromes P-450. Studies in rats and patients.

    PubMed Central

    Watkins, P B; Murray, S A; Winkelman, L G; Heuman, D M; Wrighton, S A; Guzelian, P S

    1989-01-01

    The major P-450IIIA gene family member present in human liver is HLp which, like its rat liver orthologue P-450p, is inducible by glucocorticoids and catalyzes erythromycin N-demethylation. To develop a practical method to estimate the amounts of HLp in patients [14C]N-methyl erythromycin was injected into rats that had been pretreated with dexamethasone or with inducers of other forms of cytochrome P-450. The rate of demethylation of this substrate, measured simply as 14CO2 in the breath, correlated well with the concentrations of immunoreactive P-450p protein (r = 0.70), holocytochrome P-450p (r = 0.70), or with erythromycin N-demethylase activity (r = 0.90) determined in the liver microsomes prepared from each rat. Next, [14C]N-methyl erythromycin was administered to 30 patients and there was a sixfold interindividual variation in breath 14CO2 production seemingly unrelated to medications, smoking status or age. However, the average breath test values were twofold greater in female as compared to male patients (P less than 0.01). Breath 14CO2 production rose in patients retested after treatment with the P-450IIIA inducers dexamethasone (P less than 0.05) or rifampicin (P less than 0.05) and was decreased after treatment with the HLp inhibitor triacetyloleandomycin (P less than 0.05). We conclude that the erythromycin breath test provides a convenient assay of P-450IIIA cytochromes in rats and in some patients. PMID:2913056

  7. 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.

  8. 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

  9. 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

    2015-12-01

    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. PMID:26669903

  10. 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.

  11. [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

  12. [COMPARATIVE ASSESSMENT OF MASS-SPECTROMETRY AND INFRARED SPECRTROMETRY USED IN 13C-UREA BREATH TEST FOR HELICOBACTER PYLORI].

    PubMed

    Plavnik, R G; Nevmerzhitsky, V I; Butorova, L I; Plavnik, T E

    2015-01-01

    At present, mass-spectrometry is the most accurate and efficient method for measuring carbon isotope ratio in 13C-urea breath test for H. pylori infection but its wide application is restricted by the high cost of equipment and operational complexity. IR spectrometry is one of the less expensive techniques recently proposedfor the purpose. To compare the effectiveness of the two methods, we undertook a study including 20 volunteers (6 men and 14 women) aged 18-60 years with parallel measurements by IR and mass-spectrometry. IR spectrometry was shown to be highly accurate (94-96%), sensitive (up to 100%), and specific (87.5%) which makes it a promising alternative to mass-spectrometry to be used in urea breath test for mass examination especially in outpatient facilities. PMID:27008742

  13. 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

  14. Dual therapy for third-line Helicobacter pylori eradication and urea breath test prediction

    PubMed Central

    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

    2012-01-01

    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. PMID:22690086

  15. Aperitif effects on gastric emptying: a crossover study using continuous real-time 13C breath test (BreathID System).

    PubMed

    Inamori, M; Iida, H; Endo, H; Hosono, K; Akiyama, T; Yoneda, K; Fujita, K; Iwasaki, T; Takahashi, H; Yoneda, M; Goto, A; Abe, Y; Kobayashi, N; Kubota, K; Nakajima, A

    2009-04-01

    The aim of this study was to determine whether there is a correlation between aperitif and gastric emptying. Ten healthy male volunteers participated in this randomized, two-way crossover study. Under two conditions (after drinking an aperitif versus not), the (13)C breath test was performed for 4 h with a liquid meal (200 kcal/200 ml) containing 100 mg (13)C acetate. We used 50 ml of umeshu as the aperitif. This is a traditional Japanese plum liqueur, and contains 7 ml alcohol (14%). In the aperitif group, T(1/2), T(lag), and T(peak) were significantly delayed [T(1/2) (132: 113-174) versus (112: 92-134) (P = 0.0069); T(lag) (80: 63-94) versus (55: 47-85) (P = 0.0069); and T(peak) (81: 62-96) versus (54: 34-84) (P = 0.0069), (median: range, aperitif versus control, min)]. Gastric emptying was significantly delayed in the aperitif group as compared with the control group. This study revealed that even a small amount of alcohol such as an aperitif may contribute to delayed gastric emptying. PMID:18688714

  16. Simplified single sample 13Carbon urea breath test for Helicobacter pylori: comparison with histology, culture, and ELISA serology.

    PubMed Central

    Logan, R P; Polson, R J; Misiewicz, J J; Rao, G; Karim, N Q; Newell, D; Johnson, P; Wadsworth, J; Walker, M M; Baron, J H

    1991-01-01

    There is no ideal method for detecting Helicobacter pylori. The 'standard' 13Carbon urea breath test (13C-UBT), which involves collecting eight to 15 breath samples and subsequent costly analysis, was modified by pooling 21 samples of expired breath taken at five minute intervals for 40 minutes into a collecting bag, from which a single 20 ml aliquot was taken and analysed by mass spectrometry. This test was evaluated on 50 patients after routine upper gastrointestinal endoscopy, and results were compared with those from the standard 13C-UBT, bacteriology, ELISA serology, and histology--the latter being taken as the gold standard. H pylori were seen in 34 of 50 (68%) patients (in three it was detected in biopsy specimens from the corpus alone). The modified 13C-UBT was positive (pooled excretion delta 13CO2 greater than 5 per mil) in 31 patients and negative in 19 (three false negative results), specificity was 100% (standard 13C-UBT 94%) and sensitivity 92% (standard 13C-UBT 93%). The modified 13C-UBT had a coefficient of variation within subjects of 3.7%. For the ELISA serology and culture the specificities were both 100%, but the sensitivities were 82% and 68% respectively. The 13C-UBT results correlated with the grade of histological gastritis. The modified 13C-UBT is simpler, cheaper, more reproducible, and provides an easy non-invasive method for the detection of H pylori. PMID:1773948

  17. 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.

  18. Breath odor

    MedlinePlus

    ... tube) in place. The breath may have an ammonia-like odor (also described as urine-like or " ... kidney failure (can cause breath to smell like ammonia ) Diabetes (fruity or sweet chemical smell associated with ...

  19. Breathing Problems

    MedlinePlus

    ... re not getting enough air. Sometimes mild breathing problems are from a stuffy nose or hard exercise. ... emphysema or pneumonia cause breathing difficulties. So can problems with your trachea or bronchi, which are part ...

  20. 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 ...

  1. Breath odor

    MedlinePlus

    ... is a potentially life-threatening condition. Breath that smells like feces can occur with prolonged vomiting , especially ... renal failure Bowel obstruction (can cause breath to smell like feces) Bronchiectasis Chronic kidney failure (can cause ...

  2. [Test using vapourated expired nasal breathing in medicine 100 years ago and in paestum 2 300 years ago].

    PubMed

    Pirsig, W

    2014-11-01

    This historical sketch follows the traces of a mirror, once used to test the last breath of a dying woman. It was found on the fresco of a tomb in Paestum dated about 320 BC. In 1889, Hendrik Zwaardemaker (Utrecht) was the first to present a hygrometric functional test using a cold mirror placed under the nose to estimate the degree of airflow obstruction during exhalation. In 1901, Ernst Glatzel (Berlin) modified Zwaardemaker's concept by engraving a series of equidistant arcs into his metallic mirror to further quantify the amounts of condensed vapour in the expired air. The Glatzel-mirror was used in Germany until after the Second World War. PMID:25369157

  3. [Usefulness of the integration between the values of the 1-hour blood xylose test and the hydrogen breath-test after xylose oral load for the indirect evaluation of mucosa damage].

    PubMed

    Zaniboni, M G; Lambertini, A; Romeo, N; Albini, P; Pozzi, M

    1985-01-01

    Considering 50 children affected by sub-acute gastrointestinal diseases by severe growth disorders, we have compared the "one-hour blood xylose test" with the "xylose and lactose H2 breath test, looking for a relationship with the duodeno-jejunal mucosal damage. Finally the integration between the "one hour blood xylose test" and the "xylose H2 breath test" may be useful in order to compare more exactly the results of both xylose tests with the mucosal damage. Lactose H2 breath test seems less reliable for our purposes because of the possible presence of children with lactase deficiences, hardly comparable with the mucosal damage. PMID:4094911

  4. Relationship between the single-breath N test and age, sex, and smoking habit in three North American cities.

    PubMed

    Buist, A S; Ghezzo, H; Anthonisen, N R; Cherniack, R M; Ducic, S; Macklem, P T; Manfreda, J; Martin, R R; McCarthy, D; Ross, B B

    1979-08-01

    This report describes a collaborative study conducted in Montreal, Canada, Portland, Ore., and Winnipeg, Canada, to establish the relationship between the single-breath N2 test and age, sex, and smoking and to determine the prevalence of functional abnormalities in these populations. In nonsmokers, age-related regressions for closing volume, closing capacity, and the slope of phase III obtained from the single-breath N2 test, plus the ratio of the I-s forced expiratory volume to the forced vital capacity had very similar slopes, suggesting that differences in geographic location, climate, air pollution, and occupation had no effect on lung function detectable by these tests. Among the 6 city/six groups there was no systematic difference in the prevalence of functional abnormalities between the cities, but closing capacity expressed as a percentage of total lung capacity was abnormal most often in men and the slope of the alveolar plateau was abnormal most often in women. The prevalence of respiratory symptoms within different smoking categories was similar in the 3 cities. Although the number of cigarettes smoked had a significant effect on every test except the ratio of the I-s forced expiratory volume to forced vital capacity in men, the effect of age was considerably greater than the effect of smoking, and the dose-response relationship was weak. We conclude that additional factors may interact with smoking to place a smoker at risk of developing chronic airflow limitation. PMID:475152

  5. How Accurate Are Blood (or Breath) Tests for Identifying Self-Reported Heavy Drinking Among People with Alcohol Dependence?

    PubMed Central

    Bertholet, Nicolas; Winter, Michael R.; Cheng, Debbie M.; Samet, Jeffrey H.; Saitz, Richard

    2014-01-01

    Aims Managing patients with alcohol dependence includes assessment for heavy drinking, typically by asking patients. Some recommend biomarkers to detect heavy drinking but evidence of accuracy is limited. Methods Among people with dependence, we assessed the performance of disialo-carbohydrate-deficient transferrin (%dCDT, ≥1.7%), gamma-glutamyltransferase (GGT, ≥66 U/l), either %dCDT or GGT positive, and breath alcohol (> 0) for identifying 3 self-reported heavy drinking levels: any heavy drinking (≥4 drinks/day or >7 drinks/week for women, ≥5 drinks/day or >14 drinks/week for men), recurrent (≥5 drinks/day on ≥5 days) and persistent heavy drinking (≥5 drinks/day on ≥7 consecutive days). Subjects (n = 402) with dependence and current heavy drinking were referred to primary care and assessed 6 months later with biomarkers and validated self-reported calendar method assessment of past 30-day alcohol use. Results The self-reported prevalence of any, recurrent and persistent heavy drinking was 54, 34 and 17%. Sensitivity of %dCDT for detecting any, recurrent and persistent self-reported heavy drinking was 41, 53 and 66%. Specificity was 96, 90 and 84%, respectively. %dCDT had higher sensitivity than GGT and breath test for each alcohol use level but was not adequately sensitive to detect heavy drinking (missing 34–59% of the cases). Either %dCDT or GGT positive improved sensitivity but not to satisfactory levels, and specificity decreased. Neither a breath test nor GGT was sufficiently sensitive (both tests missed 70–80% of cases). Conclusions Although biomarkers may provide some useful information, their sensitivity is low the incremental value over self-report in clinical settings is questionable. PMID:24740846

  6. Evaluation of three commercial enzyme immunoassays compared with the 13C urea breath test for detection of Helicobacter pylori infection.

    PubMed Central

    Marchildon, P A; Ciota, L M; Zamaniyan, F Z; Peacock, J S; Graham, D Y

    1996-01-01

    The diagnostic significance of the serological detection of antibodies to Helicobacter pylori has been established by numerous investigators. Reports of the clinical reliabilities of commercial enzyme immunoassay (EIA) kits available for this purpose vary as a result of the different H. pylori antigen sources and reference methods used. The 13C urea breath test (UBT) has been shown to be an extremely accurate and reliable method of detecting H. pylori infection. We used the 13C urea breath test as the confirmatory method for H. pylori status to evaluate three commercially available EIA kits designed to detect immunoglobulin G antibodies to H. pylori. These kits were the HM-CAP EIA kit (Enteric Products, Inc.), the PYLORI STAT EIA kit (BioWhittaker, Inc.), and the G.A.P. kit (Bio-Rad Laboratories/Biomerica, Inc.). The evaluations were performed in a double-blind manner with samples from 473 clinically characterized patients. This group included patients with symptomatic gastrointestinal disorders as well as nonsymptomatic volunteers. The sensitivities of the kits were as follows: HM-CAP, 98.4%; PYLORI STAT, 99.2%; and G.A.P., 100%. The specificities were as follows: HM-CAP, 96.4%; PYLORI STAT, 90.1%; and G.A.P., 26.0%. Although the HM-CAP and PYLORI STAT kits performed comparably, the G.A.P. test yielded significantly more false-positive results and an unacceptably high number of indeterminate results. PMID:8727892

  7. Efficacy and cost-effectiveness of the 13C-urea breath test as the primary diagnostic investigation for the detection of Helicobacter pylori infection compared to invasive and non-invasive diagnostic tests

    PubMed Central

    Nocon, Marc; Kuhlmann, Alexander; Leodolter, Andreas; Roll, Stephanie; Vauth, Christoph; Willich, Stefan N.; Greiner, Wolfgang

    2009-01-01

    Background Helicobacter pylori (H. pylori) is one of the most common bacterial infections in humans. There is a risk factor for gastric or duodenal ulcers, gastric cancer and MALT (Mucosa Associated Lymphoid Tissue)-Lymphomas. There are several invasive and non-invasive methods available for the diagnosis of H. pylori. The 13C-urea breath test is a non-invasive method recommended for monitoring H. pylori eradication therapy. However, this test is not yet used for primary assessment of H. pylori in Germany. Objectives What are the clinical and health economic benefits of the 13C-urea breath test in the primary assessment of H. pylori compared to other invasive and non-invasive methods? Methods A systematic literature search including a hand search was performed for studies investigating test criteria and cost-effectiveness of the 13C-urea breath test in comparison to other methods used in the primary assessment of H. pylori. Only studies that directly compared the 13C-urea breath test to other H. pylori-tests were included. For the medical part, biopsy-based tests were used as the gold standard. Results 30 medical studies are included. Compared to the immunoglobulin G (IgG) test, the sensitivity of the 13C-urea breath test is higher in twelve studies, lower in six studies and one study reports no differences. The specificity is higher in 13 studies, lower in three studies and two studies report no differences. Compared to the stool antigen test, the sensitivity of the 13C-urea breath test is higher in nine studies, lower in three studies and one study reports no difference. The specificity is higher in nine studies, lower in two studies and two studies report no differences. Compared to the urease test, the sensitivity of the 13C-urea breath test is higher in four studies, lower in three studies and four studies report no differences. The specificity is higher in five studies, lower in five studies and one study reports no difference. Compared to histology, the

  8. Dirhythmic breathing.

    PubMed

    Flemister, G; Goldberg, N B; Sharp, J T

    1981-01-01

    Four patients with severe chronic obstructive lung disease and recent respiratory failure are described in whom two distinct simultaneous respiratory rhythms were identified, one at 8 to 13 breaths per minute and the other at 39 to 65 per minute. Magnetometer measurements of thoracoabdominal motion together with simultaneous electromyograms of multiple inspiratory muscles suggested that both rhythms were the result of coordinated action of several inspiratory muscles. We suggest that this phenomenon, which we have called dirhythmic breathing, results from the conflicting influence upon respiratory centers and motoneurons of two or more stimuli, some favoring rapid shallow breaths and others slow deep breaths. PMID:7449504

  9. 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.

  10. Evaluation of 13C-urea breath test in the detection of Helicobacter pylori and in monitoring the effect of tripotassium dicitratobismuthate in non-ulcer dyspepsia.

    PubMed Central

    Dill, S; Payne-James, J J; Misiewicz, J J; Grimble, G K; McSwiggan, D; Pathak, K; Wood, A J; Scrimgeour, C M; Rennie, M J

    1990-01-01

    Sixty nine patients with non-ulcer dyspepsia have been studied with endoscopy, biopsy, quick urease (CLO) test, Helicobacter pylori culture, and the 13C-urea breath test before and after treatment with tripotassium dicitratobismuthane (DeNol) two tablets twice daily for four weeks. Symptoms of non-ulcer dyspepsia were recorded using a standard questionnaire. Using H pylori culture as the gold standard, the sensitivity of the 13C-urea breath test was 90%, the specificity 98.6%, and the accuracy 94.8% with a positive predictive value of 98.2% and a negative predictive value of 92.5%. Conversion rate from H pylori positive to negative status after treatment with tripotassium dicitratobismuthate was 17.9%. Symptoms of non-ulcer dyspepsia improved appreciably after treatment irrespective of H pylori status. The 13C-urea breath test is an accurate research tool suitable for serial testing and population surveys. PMID:2253905

  11. Evaluation of [13C]Urea Breath Test and Helicobacter pylori Stool Antigen Test for Diagnosis of H. pylori Infection in Children from a Developing Country

    PubMed Central

    Cardinali, Luciana de Carvalho Costa; Rocha, Gifone Aguiar; Rocha, Andreia Maria Camargos; de Moura, Sílvia Beleza; de Figueiredo Soares, Taciana; Esteves, Ana Maria Braz; Nogueira, Ana Margarida Miguel Ferreira; Cabral, Mônica Maria Demas Álvares; de Carvalho, Anfrisina Sales Teles; Bitencourt, Paulo; Ferreira, Alexandre; Queiroz, Dulciene Maria Magalhães

    2003-01-01

    The [13C]urea breath test (13C-UBT) and Helicobacter pylori stool antigen test (HpSA) for the diagnosis of H. pylori infection in children were validated. The sensitivity, specificity, and positive and negative predictive values were 93.8, 99.1, 97.8, and 98.0%, respectively, for the 13C-UBT and 96.9, 100, 100, and 98.0%, respectively, for HpSA. Both tests are appropriate for diagnosing H. pylori infection in children. PMID:12843086

  12. Lactose malabsorption testing in daily clinical practice: a critical retrospective analysis and comparison of the hydrogen/methane breath test and genetic test (c/t-13910 polymorphism) results.

    PubMed

    Enko, Dietmar; Rezanka, Erwin; Stolba, Robert; Halwachs-Baumann, Gabriele

    2014-01-01

    The aim of this study was to establish a retrospective evaluation and comparison of the hydrogen/methane (H2/CH4) breath test and genetic test (C/T-13910 polymorphism) results in lactose malabsorption testing. In total 263 consecutive patients with suspected lactose malabsorption were included in this study. They underwent the H2/CH4 breath test following the ingestion of 50 g lactose and were tested for the C/T-13910 polymorphism. In total 51 patients (19.4%) had a C/C-13910 genotype, indicating primary lactose malabsorption. Only 19 patients (7.2%) also had a positive H2/CH4 breath test. All in all 136 patients (51.69%) had a C/T-13910 and 76 patients (28.91%) a T/T-13910 genotype, indicating lactase persistence. Four patients (1.5%) with the C/T-13910 genotype and one patient (0.4%) with the T/T-13910 genotype had a positive H2/CH4 breath test result, indicating secondary lactose malabsorption. Cohen's Kappa measuring agreement between the two methods was 0.44. Twenty patients (7.6%) with a positive H2/CH4 peak within 60 minutes after lactose ingestion were classified as patients with lactose-dependent small intestinal bacterial overgrowth (SIBO). In conclusion, only moderate agreement between the breath test and the genetic test was shown. Secondary lactose malabsorption as well as preanalytical limitations of the combined H2/CH4 breath test procedure can cause discrepant results. This trial is registered with K-42-13. PMID:24829570

  13. Lactose Malabsorption Testing in Daily Clinical Practice: A Critical Retrospective Analysis and Comparison of the Hydrogen/Methane Breath Test and Genetic Test (C/T−13910 Polymorphism) Results

    PubMed Central

    Rezanka, Erwin; Stolba, Robert; Halwachs-Baumann, Gabriele

    2014-01-01

    The aim of this study was to establish a retrospective evaluation and comparison of the hydrogen/methane (H2/CH4) breath test and genetic test (C/T−13910 polymorphism) results in lactose malabsorption testing. In total 263 consecutive patients with suspected lactose malabsorption were included in this study. They underwent the H2/CH4 breath test following the ingestion of 50 g lactose and were tested for the C/T−13910 polymorphism. In total 51 patients (19.4%) had a C/C−13910 genotype, indicating primary lactose malabsorption. Only 19 patients (7.2%) also had a positive H2/CH4 breath test. All in all 136 patients (51.69%) had a C/T−13910 and 76 patients (28.91%) a T/T−13910 genotype, indicating lactase persistence. Four patients (1.5%) with the C/T−13910 genotype and one patient (0.4%) with the T/T−13910 genotype had a positive H2/CH4 breath test result, indicating secondary lactose malabsorption. Cohen's Kappa measuring agreement between the two methods was 0.44. Twenty patients (7.6%) with a positive H2/CH4 peak within 60 minutes after lactose ingestion were classified as patients with lactose-dependent small intestinal bacterial overgrowth (SIBO). In conclusion, only moderate agreement between the breath test and the genetic test was shown. Secondary lactose malabsorption as well as preanalytical limitations of the combined H2/CH4 breath test procedure can cause discrepant results. This trial is registered with K-42-13. PMID:24829570

  14. Validity and cost comparison of 14carbon urea breath test for diagnosis of H Pylori in dyspeptic patients

    PubMed Central

    Rasool, Shahid; Abid, Shahab; Jafri, Wasim

    2007-01-01

    AIM: To validate and compare the cost of microdose 14C urea breath test (UBT) with histology and rapid urease test for the diagnosis of H Pylori. METHODS: Ninety-four consecutive patients with dyspeptic symptoms undergoing gastroscopy were enrolled. Gastric biopsies were taken for histology and rapid urease test. UBT was performed after gastroscopy by microdose 14C urea capsules. Sensitivity, specificity and accuracy of UBT were calculated and compared with histology and rapid urease test. Cost comparison of these tests was also performed. RESULTS: H pylori was diagnosed by histology and rapid urease test in 66 (70%) and 61 (65%) patients, while 14C UBT detected infection in 63 (67%). Accuracy of UBT was 93% in comparison with histology while its positive and negative predictive values were 97% and 84%, respectively. Comparison of 14C UBT with rapid urease test gives an accuracy of 96%, with positive and negative predictive values of 95% and 97%, respectively. These results were highly reproducible with a Kappa test (P value < 0.001). Cost of histology or rapid urease test with gastroscopy was 110 USD or 95 USD respectively while the cost of UBT was 15 USD. CONCLUSION: Microdose 14C UBT was comparable to histology and rapid urease test. 14C UBT is an economical, self sufficient and suitable test to diagnose active H pylori infection in less developed countries. PMID:17352025

  15. 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.

  16. Breathing Problems

    MedlinePlus

    When you're short of breath, it's hard or uncomfortable for you to take in the oxygen your body needs. You may feel as if you're ... stuffy nose or hard exercise. But shortness of breath can also be a sign of a serious ...

  17. 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.

  18. 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.

  19. A citric acid solution is an optimal test drink in the 13C-urea breath test for the diagnosis of Helicobacter pylori infection.

    PubMed Central

    Domínguez-Muñoz, J E; Leodolter, A; Sauerbruch, T; Malfertheiner, P

    1997-01-01

    BACKGROUND: The 13C-urea breath test (13C-UBT) is a simple, non-invasive and reliable test for the diagnosis of Helicobacter pylori infection. The duration of the test, the timing of breath sampling, and the accuracy of the method vary according to the test meal used. AIM: To identify the optimal test meal or drink for rapid and accurate performance of the 13C-UBT for the detection of H pylori infection. PATIENTS: Eighty patients with dyspeptic symptoms were included. Of these, 48 patients had a positive H pylori status and 32 a negative one according to the results of the rapid urease test, histological examination, and culture. METHODS: A 13C-UBT was performed after an overnight fast, on three consecutive days. On each study day a different test meal or drink was given (0.1 N citric acid solution, a standard semiliquid meal, or a semiliquid fatty meal) 10 minutes before giving 75 mg 13C-urea. Breath samples were collected at 0, 15, 30, 45, and 60 minutes, and analysed by isotype ratio mass spectrometry. Results were expressed as delta (delta) and considered as positive for H pylori if the highest delta (peak) was greater than 4.0. RESULTS: The delta peak obtained with the citric acid drink in H pylori positive subjects (24.1 (SEM 1.5)) was significantly higher than that obtained with any of the semiliquid meals (13.3 (SEM 1.1) and 17.1 (SEM 1.0) respectively, p < 0.001). Furthermore, this delta peak was obtained earlier with the citric acid drink (30 (SEM 2) minutes) than with the other two meals tests (53 (SEM 2) min and 45 (SEM 2) min, p < 0.001). The sensitivity of the 13C-UBT for the diagnosis of H pylori infection was 96-100% with all three test meals. This high sensitivity was, however, obtained from 15 minutes by giving citric acid as the test drink, from 45 minutes by giving a semiliquid fatty meal, and at 60 minutes by giving the semiliquid standard meal. The specificity was 100% for all test meals. Citric acid is inexpensive and palatable to patients

  20. Medical devices; clinical chemistry and clinical toxicology devices; classification of the breath nitric oxide test system. Final rule.

    PubMed

    2003-07-01

    The Food and Drug Administration (FDA) is classifying the breath nitric oxide test system into class II (special controls). The agency is taking this action in response to a petition submitted under the Federal Food, Drug, and Cosmetic Act (the act) as amended by the Medical Device Amendments of 1976 (the 1976 amendments), the Safe Medical Devices Act of 1990 (the SMDA), and the Food and Drug Administration Modernization Act of 1997 (FDAMA). The agency is classifying this device into class II (special controls) in order to provide a reasonable assurance of safety and effectiveness of the device. Elsewhere in this issue of the Federal Register, FDA is announcing the availability of a guidance document that will serve as the special control for the device. PMID:12858842

  1. Bad Breath

    MedlinePlus

    ... mouth and between your teeth produce the bad odor. Other problems in your mouth, such as gum ... and medicines are associated with a specific breath odor. Having good dental habits, like brushing and flossing ...

  2. Bad Breath

    MedlinePlus

    ... hygiene leads to bad breath because when food particles are left in your mouth, they can rot ... Flossing once a day helps get rid of particles wedged between your teeth. Also, visit your dentist ...

  3. Breath sounds

    MedlinePlus

    The lung sounds are best heard with a stethoscope. This is called auscultation. Normal lung sounds occur ... the bottom of the rib cage. Using a stethoscope, the doctor may hear normal breathing sounds, decreased ...

  4. Cardiogenic oscillation phase relationships during single-breath tests performed in microgravity.

    PubMed

    Lauzon, A M; Elliott, A R; Paiva, M; West, J B; Prisk, G K

    1998-02-01

    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. PMID:9475878

  5. 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.

  6. Rapid 13C Urea Breath Test to Identify Helicobacter pylori Infection in Emergency Department Patients with Upper Abdominal Pain

    PubMed Central

    Meltzer, Andrew C.; Pierce, Rebecca; Cummings, Derek A.T.; Pines, Jesse M.; May, Larissa; Smith, Meaghan A.; Marcotte, Joseph; McCarthy, Melissa L.

    2013-01-01

    Introduction: In emergency department (ED) patients with upper abdominal pain, management includes ruling out serious diseases and providing symptomatic relief. One of the major causes of upper abdominal pain is an ulcer caused by Helicobacter pylori (H. pylori), which can be treated and cured with antibiotics. We sought to estimate the prevalence of H. pylori infection in symptomatic patients using a convenience sample at a single urban academic ED and demonstrate the feasibility of ED-based testing. Methods: We prospectively enrolled patients with a chief complaint of pain or discomfort in the upper abdomen for 1 year from February 2011 until February 2012 at a single academic urban ED. Enrolled subjects were tested for H. pylori using a rapid point of care 13C Urea Breath Test (UBT) [Exalenz Bioscience]. We compared patient characteristics between those who tested positive versus negative for the disease. Results: A total of 205 patients with upper abdominal pain were tested over 12 months, and 24% (95% confidence interval: 19% to 30%) tested positive for H. pylori. Black subjects were more likely to test positive than white subjects (28% v. 6%, P < 0.001). Other factors, such as age and sex, were not different between the 2 groups. Conclusion: In our ED, H. pylori infection was present in 1 in 4 patients with epigastric pain, and testing with a UBT was feasible. Further study is needed to determine the risk factors associated with infection, the prevalence of H. pylori in other EDs, the effect of the test on ED length of stay and the costeffectiveness of an ED-based test-and-treat strategy. PMID:23687549

  7. Impact of long-term ranitidine and pantoprazole on accuracy of [13C]urea breath test.

    PubMed

    Dulbecco, Pietro; Gambaro, Camilla; Bilardi, Claudio; Zentilin, Patrizia; Mele, Maria Raffaella; Mansi, Carlo; Biagini, Riccardo; Tessieri, Laura; Iiritano, Elena; Usai, Paolo; Vigneri, Sergio; Savarino, Vincenzo

    2003-02-01

    No previous study has analyzed the impact of long-term antisecretory drugs on the precision of [13C]urea breath test (UBT). We assessed the rate of UBT conversion from positive to negative results during 60-day therapy with standard doses of ranitidine and pantoprazole. For this purpose, we recruited 60 dyspeptic patients with H. pylori infection ascertained on the basis of the concomitant results of CLO-test, histology, and UBT. Our patients were randomly assigned to receive ranitidine 300 mg at night or pantoprazole 40 mg in the morning for 60 days. UBT was performed at baseline and on days 14, 30, and 60, while patients were still taking antisecretory drugs. Patients with false-negative UBT on day 60 repeated the test every 3 days until conversion. After overnight fasting, duplicate breath test samples were taken from each patient before and 30 min after ingestion of 75 mg [13C]urea dissolved in 150 ml of 0.033 mol/liter citric acid. Four patients dropped out of the study. Both drugs induced similar false-negative UBTs on day 14 of dosing (P = 0.5). Afterwards, the three false-negative UBTs in the ranitidine group again became positive during therapy and particularly on day 30 of dosing. Of the four false-negative UBTs in the pantoprazole group at day 60, one became positive after 3 and three after 9 days of therapy cessation. Our findings show that the long-term use of ranitidine and pantoprazole at standard doses has different effects on the results of UBT. In the pantoprazole group patients again became positive within 3-9 days after stopping 60-day therapy, whereas in the ranitidine group patients reverted to positive on day 30 of dosing while they were still on treatment and this was likely due to development of tolerance. Therefore, patients taking pantoprazole need at least a 10-day withdrawal before UBT testing, while those taking ranitidine for at least 30 days can undergo UBT without the necessity of a wash-out period. PMID:12643609

  8. Comparison of the 1-gram (/sup 14/C)xylose, 10-gram lactulose-H/sub 2/, and 80-gram glucose-H/sub 2/ breath tests in patients with small intestine bacterial overgrowth

    SciTech Connect

    King, C.E.; Toskes, P.P.

    1986-12-01

    The sensitivity of three breath tests (1-g (/sup 14/C)xylose, 10-g lactulose-H/sub 2/, and 80-g glucose-H/sub 2/) was studied in 20 subjects with culture-documented small intestine bacterial overgrowth. Elevated breath /sup 14/CO2 levels were seen within 30 min of (/sup 14/C)xylose administration in 19 of 20 subjects with bacterial overgrowth and 0 of 10 controls. In contrast, H/sub 2/ breath tests demonstrated uninterpretable tests (absence of H/sub 2/-generating bacteria) in 2 of 20 subjects with bacterial overgrowth and 1 of 10 controls and nondiagnostic increases in H/sub 2/ production in 3 of 18 glucose-H/sub 2/ and 7 of 18 lactulose-H/sub 2/ breath tests in subjects with bacterial overgrowth. These findings demonstrate continued excellent reliability of the 1-g (/sup 14/C)xylose breath test as a diagnostic test for bacterial overgrowth, indicate inadequate sensitivity of H/sub 2/ breath tests in detecting bacterial overgrowth, and suggest the need for evaluation of a /sup 13/CO/sub 2/ breath test having the same characteristics as the (/sup 14/C)xylose test (avidly absorbed substrate having minimal contact with the colonic flora) for nonradioactive breath detection of bacterial overgrowth in children and reproductive-age women.

  9. 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

    2015-06-01

    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. PMID:25891764

  10. 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

  11. 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

  12. Carbon sequestration and estimated carbon credit values as measured using 13C labelling and analysis by means of an optical breath test analyser.

    PubMed

    Hood, R C; Khan, M; Haque, A; Khadir, M; Bonetto, J P; Syamsul, R; Mayr, L; Heiling, M

    2004-05-01

    Recent developments in optical systems (isotope-selective non-dispersive infrared spectrometry) for breath testing have provided a robust, low-cost option for undertaking (13)C analysis. Although these systems were initially developed for breath testing for Helicobacter pylori, they have an enormous potential as a soil science research tool. The relatively low cost of the equipment, US$15,000-25,000, is within the research budgets of most institutes or universities. The simplicity of the mechanisms and optical nature mean that the equipment requires relatively low maintenance and minimal training. Thus methods were developed to prepare soil and plant materials for analysis using the breath test analyser. Results that compare conventional mass spectrometric methods with the breath test analyser will be presented. In combination with simple (13)C-plant-labeling techniques it is possible to devise methods for estimating carbon sequestration under different agronomic management practices within a short time frame. This enables assessment of the carbon credit value of a particular agronomic practice, which can in turn be used by policy makers for decision-making purposes. For global understanding of the effect of agricultural practices on the carbon cycle, data are required from a range of cropping systems and agro-ecological zones. The method and the approach described will enable collection of hard data within a reasonable time. PMID:14963630

  13. 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; ...

  14. [COMPARATIVE EVALUATION OF THE EFFECTIVENESS OF THE USE OF 13C-LABELED MIXED TRIGLYCERIDE AND 13C-STARCH BREATH TESTS IN PATIENTS WITH CHRONIC PANCREATITIS AFTER CHOLECYSTECTOMY].

    PubMed

    Sirchak, Ye S

    2015-01-01

    The results of a comprehensive study of 96 patients after cholecystectomy are provided. The higher sensitivity and informativeness of the 13C-labeled mixed triglyceride breath .test compared with 13C-starch breath test for determining functional pancreatic insufficiency in patients after cholecystectomy in early stages of its formation was set. PMID:27491156

  15. 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.

  16. 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

  17. 13C urea breath test (UBT) in the diagnosis of Helicobacter pylori: why does it work better with acid test meals?

    PubMed Central

    Pantoflickova, D; Scott, D R; Sachs, G; Dorta, G; Blum, A L

    2003-01-01

    Background: Acid test meals may improve the accuracy of the 13C urea breath test (UBT). This has been attributed to changes in gastric emptying rather than to the effects of gastric pH on Helicobacter pylori urease. Aims: To determine whether enhancement of 13CO2 excretion in the UBT in H pylori infected volunteers by acidification of a test meal is due to a delay in gastric emptying. Methods: Urease activity in vitro was measured in intact bacteria and in bacterial homogenates. Urease activity in vivo was assessed by means of the UBT. Eleven H pylori infected subjects underwent UBTs with neutral Ensure (pH 7.0), acidified Ensure (pH 3.0), and apple juice (pH 3.0). Gastric emptying was assessed by 13C sodium acetate breath test. Results: From pH 7 to pH 3, the in vitro urease activity of intact bacteria increased sixfold. In contrast, urease activity of bacterial homogenates was inactivated by low pH. In vivo, urease activity, as measured by the UBT 20 minutes after meal ingestion, was higher with apple juice (δ 13CO2=21.1; p=0.03) and acidified Ensure (δ 13CO2=25.5; p=0.01) than with neutral Ensure (δ 13CO2=12.5). Gastric emptying was faster with apple juice (Tmax=36.7 (8) minutes) but not with acidified Ensure (Tmax=63.3 (5) minutes; p=0.06) than with neutral Ensure (Tmax=65.0 (3) minutes; p=0.04). Conclusions: The higher UBT found with acidified compared with neutral test meals was independent of the emptying rates of the test meals but may have been due to medium acidity dependent activation of intra-bacterial urease in intact H pylori. PMID:12801946

  18. Breathing difficulty - lying down

    MedlinePlus

    ... breath; Paroxysmal nocturnal dyspnea; PND; Difficulty breathing while lying down; Orthopnea ... Obesity (does not directly cause difficulty breathing while lying down but often worsens other conditions that lead ...

  19. Effect of a test meal on the intragastric distribution of urea in the 13C-urea breath test for Helicobacter pylori.

    PubMed Central

    Atherton, J C; Washington, N; Blackshaw, P E; Greaves, J L; Perkins, A C; Hawkey, C J; Spiller, R C

    1995-01-01

    Test meals are invariably used in the 13C-urea breath test (UBT) but their effect on the intragastric distribution and gastric residence time of urea given in the test is unknown. The site of Helicobacter pylori urease measured in the test is unknown and whether the test measures total or regional gastric urease is uncertain. This study reports the results of paired UBTs with simultaneous gastric distribution studies, one with and one without a fatty test meal, two weeks apart on seven H pylori infected subjects. The test meal did not affect UBT results at 10 minutes, but increased values at 30 minutes and thereafter. The amount of scintigraphic label in the antrum at 10 minutes was also unaffected by the meal but increased at 30 minutes and thereafter, whereas the amount in the body/fundus was greatly increased both at 10 minutes and throughout the test. There was considerable variation in intragastric distribution of urea between subjects, both with and without the test meal. This study shows that a test meal profoundly affects intragastric distribution of urea solution in the UBT, and increases UBT values at 30 minutes and later. Variability between subjects, however, means that accurate measurement of total or regional gastric urease is probably unrealistic. Images Figure 1 PMID:7698688

  20. Pharmacological modulation of gastric emptying rate of solids as measured by the carbon labelled octanoic acid breath test: influence of erythromycin and propantheline.

    PubMed Central

    Maes, B D; Hiele, M I; Geypens, B J; Rutgeerts, P J; Ghoos, Y F; Vantrappen, G

    1994-01-01

    The *C (13C or 14C) labelled octanoic acid breath test was recently developed to measure the gastric emptying rate of solids. This study aimed to investigate whether it is sensitive enough to detect pharmacologically induced changes in the gastric emptying rate. Nine healthy volunteers were studied in basal condition, after intravenous administration of 200 mg erythromycin, and after peroral administration of 30 mg propantheline. Erythromycin significantly enhanced gastric emptying in all subjects, with an increase of the gastric emptying coefficient (p = 0.0043) in eight of nine and a fall in both the gastric half emptying time (p = 0.0020) and the lag phase (p = 0.0044) in all nine. Propantheline significantly reduced the gastric emptying rate, with a decreased gastric emptying coefficient (p = 0.0007) and an increased gastric half emptying time (p = 0.0168) in all subjects, but no change in the lag phase (p = 0.1214). Further mathematical analysis showed that breath sampling at 15 minutes intervals over a four hour period is recommended to guarantee accuracy and the discriminative value of the breath test in various gastric emptying patterns. In conclusion the *C labelled octanoic acid breath test is sufficiently sensitive to show pharmacologically induced changes of gastric emptying rates of solids. PMID:8150342

  1. 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.

  2. 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.

  3. Traveling with breathing problems

    MedlinePlus

    If you have breathing problems and you: Are short of breath most of the time Get short of breath when you walk 150 ... or less Have been in the hospital for breathing problems recently Use oxygen at home, even if ...

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

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., administrative actions, and civilian courts. (d) Special rules exist for persons who have hemophilia, other blood-clotting disorders, or any medical or surgical disorder being treated with an anticoagulant. These persons— (1) May refuse a blood extraction test without penalty. (2) Will not be administered a...

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

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., administrative actions, and civilian courts. (d) Special rules exist for persons who have hemophilia, other blood-clotting disorders, or any medical or surgical disorder being treated with an anticoagulant. These persons— (1) May refuse a blood extraction test without penalty. (2) Will not be administered a...

  6. 32 CFR 634.37 - Voluntary breath and bodily fluid testing based on implied consent.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., administrative actions, and civilian courts. (d) Special rules exist for persons who have hemophilia, other blood-clotting disorders, or any medical or surgical disorder being treated with an anticoagulant. These persons— (1) May refuse a blood extraction test without penalty. (2) Will not be administered a...

  7. 32 CFR 634.37 - Voluntary breath and bodily fluid testing based on implied consent.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., administrative actions, and civilian courts. (d) Special rules exist for persons who have hemophilia, other blood-clotting disorders, or any medical or surgical disorder being treated with an anticoagulant. These persons— (1) May refuse a blood extraction test without penalty. (2) Will not be administered a...

  8. 32 CFR 634.37 - Voluntary breath and bodily fluid testing based on implied consent.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., administrative actions, and civilian courts. (d) Special rules exist for persons who have hemophilia, other blood-clotting disorders, or any medical or surgical disorder being treated with an anticoagulant. These persons— (1) May refuse a blood extraction test without penalty. (2) Will not be administered a...

  9. Comparison of a monoclonal antigen stool test (Hp StAR) with the 13C-urea breath test (UBT) in monitoring Helicobacter pylori eradication therapy

    PubMed Central

    Perri, Francesco; Quitadamo, Michele; Ricciardi, Rosalba; Piepoli, Ada; Cotugno, Rosa; Gentile, Annamaria; Pilotto, Alberto; Andriulli, Angelo

    2005-01-01

    AIM: To evaluate the agreement between a mAb-based stool test (HP StAR) and the urea breath test (UBT) in monitoring (H pylori) infection after eradication therapy. METHODS: Patients with discordant results on UBT and Hp StAR underwent endoscopy with biopsies for rapid urease test, culture, and histology to confirm H pylori status. RESULTS: Among 250 patients (50±14 years), 240 (96.0%) had concordant UBT and Hp StAR tests with a significant correlation between DOB and A values (R = 0.87; P<0.0001). The remaining 10 (4.0%) patients had discordant tests (positive Hp StAR and negative UBT) with the Hp StAR inaccurate in five cases (false positive) and UBT inaccurate in the other five cases (false negative). The “maximal expected” sensitivity, specificity, +PV, -PV, +LR, and -LR were 91%, 100%, 100%, 97.4%, , and 8.2 respectively, for the UBT, and 100%, 97.4%, 91%, 100%, 38.8, and 0, respectively, for the Hp StAR. Overall accuracy for both tests was 98%. CONCLUSION: Both the UBT and the Hp StAR are equally accurate in monitoring H pylori infection. Nowadays, the choice of the “best” non-invasive H pylori test in the post-treatment setting should be done not only in terms of diagnostic accuracy but also in view of cost and local facilities. PMID:16270402

  10. 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.

  11. 13C-methacetin breath test reproducibility study reveals persistent CYP1A2 stimulation on repeat examinations

    PubMed Central

    Kasicka-Jonderko, Anna; Nita, Anna; Jonderko, Krzysztof; Kamińska, Magdalena; Błońska-Fajfrowska, Barbara

    2011-01-01

    AIM: To find the most reproducible quantitative parameter of a standard 13C-methacetin breath test (13C-MBT). METHODS: Twenty healthy volunteers (10 female, 10 male) underwent the 13C-MBT after intake of 75 mg 13C-methacetin p.o. on three occasions. Short- and medium-term reproducibility was assessed with paired examinations taken at an interval of 2 and 18 d (medians), respectively. RESULTS: The reproducibility of the 1-h cumulative 13C recovery (AUC0-60), characterized by a coefficient of variation of 10%, appeared to be considerably better than the reproducibility of the maximum momentary 13C recovery or the time of reaching it. Remarkably, as opposed to the short gap between consecutive examinations, the capacity of the liver to handle 13C-methacetin increased slightly but statistically significantly when a repeat dose was administered after two to three weeks. Regarding the AUC0-60, the magnitude of this fixed bias amounted to 7.5%. Neither the time gap between the repeat examinations nor the gender of the subjects affected the 13C-MBT reproducibility. CONCLUSION: 13C-MBT is most reproducibly quantified by the cumulative 13C recovery, but the exactitude thereof may be modestly affected by persistent stimulation of CYP1A2 on repeat examinations. PMID:22174547

  12. 13C-Urea breath test threshold calculation and evaluation for the detection of Helicobacter pylori infection in children

    PubMed Central

    Herold, Ralf; Becker, Michael

    2002-01-01

    Background The 13C-urea breath test (UBT) is performed in adults and children with epigastric pain for non-invasively diagnosing a suspected H. pylori infection. Criteria for UBT interpretation have not been generally agreed on and test reliability has not been established in children of different ages. This study aimed at identifying reliable UBT thresholds in children by using 251 UBTs in conjunction with reference histology and by analyzing 1232 UBTs. Methods At baseline and 30 and 60 minutes after the administration of 75 mg 13C-urea to children and adolescents (0.25 to 18 years of age), the differences (Δ) of 13CO2/12CO2 ratio in exhaled air (δ) were determined by mass spectrometry. UBT Δδ value thresholds were calculated in random subgroups and evaluated in complementary subgroups using logistic regressions on reference histology or bimodal distribution analyses of Δδ values from UBTs alone. Results Δδ values were higher (median, 15.4‰) in positive (133/251, 53 %) than in negative histology (2.4‰). At 30 minutes, the calculated cut-off was 5.3‰ (mean regression determination R2 = 0.91), and sensitivity (0.95), specificity (0.97), positive (0.97) and negative predictive values (0.95) were higher than at 60 minutes (threshold 6.8‰, R2 = 0.85). Similar thresholds resulted from UBTs analysis (5.8‰ and 6.2‰) when sensitivity and specificity were maximized (concordance probabilities, 0.99 and 0.99). There was no systematic age effect. Conclusions In children, 13C UBT cut-offs were obtained and specially validated, entailing high accuracy of non-invasively testing for gastric H. pylori infection. PMID:12014996

  13. Diagnosis of Helicobacter pylori Infection in Children: Comparison of a Salivary Immunoglobulin G Antibody Test with the [13C]Urea Breath Test

    PubMed Central

    Bode, G.; Marchildon, P.; Peacock, J.; Brenner, H.; Rothenbacher, D.

    2002-01-01

    The prevalence of Helicobacter pylori infection in a population-based sample of 477 children (mean age ± standard deviation, 5.8 ± 0.5 years) determined by the [13C]urea breath test ([13C]UBT) was 10.7% (95% confidence interval [CI], 8.1 to 13.8%), and that determined by salivary enzyme-linked immunosorbent assay (ELISA) was 11.9% (95% CI, 9.2 to 15.2%). Compared to the [13C]UBT, the sensitivity and specificity of the salivary ELISA were 80.9% (95% CI, 66.3 to 90.4%) and 95.3% (95% CI, 92.7 to 97.1%), respectively. PMID:11874901

  14. 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.

  15. 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. ...

  16. 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. PMID:26028929

  17. Breath alcohol test

    MedlinePlus

    ... in the tube change colors (from yellow to green), depending on the alcohol content. Carefully read the ... When 1 band is green, it means that the blood-alcohol level is 0.05% or lower. 2 green bands mean levels of 0.05% ...

  18. Role of the 13C-methacetin breath test in the assessment of acute liver injury in a rat model

    PubMed Central

    Zhu, Dong; Zhang, Hui; Mao, Jing-Yi; Wang, Hong-Yan; Li, Xin; Xu, You-Qing

    2014-01-01

    AIM: To evaluate the role of the 13C-methacetin breath test (13C-MBT) in the assessment of acute liver injury in a rat model. METHODS: Acute liver injury in rats was induced by a single intraperitoneal injection of D-galactosamine (D-GalN). Forty-eight male Sprague-Dawley rats were randomly assigned to a control group (n = 8) and five model groups (each n = 8), and acute liver injury was assessed at different time points (6, 12, 24, 48 and 72 h) after D-GalN injection. The 13C-MBT, biochemical tests, 15-min retention rate of indocyanine green (ICGR15), and liver biopsy were performed and compared between the control and model groups. Correlations between parameters of the 13C-MBT (Tmax, MVmax, CUM120 and DOBmax), biochemical tests, ICGR15 and liver necrosis score were also analyzed using Spearman’s correlation analysis. RESULTS: Tmax, MVmax, CUM120 and DOBmax, as well as most of the traditional methods, correlated with the liver necrosis score (r = 0.493, P < 0.05; r = -0.731, P < 0.01; r = -0.618, P < 0.01; r = -0.592, P < 0.01, respectively). MVmax, CUM120 and DOBmax rapidly decreased and were lower than those in the controls as early as 6 h after D-GalN injection (3.84 ± 0.84 vs 5.06 ± 0.78, P < 0.01; 3.35 ± 0.72 vs 4.21 ± 1.44, P < 0.05; 52.3 ± 20.58 vs 75.1 ± 9.57, P < 0.05, respectively) and reached the lowest point 24 h after D-GalN injection. MVmax, CUM120 and DOBmax returned to normal levels 72 h after D-GalN injection and preceded most of the traditional methods, including liver biopsy. CONCLUSION: The 13C-MBT is a sensitive tool for the timely detection of acute liver injury and early prediction of recovery in a rat model. Further clinical studies are warranted to validate its role in patients with acute liver injury. PMID:25170215

  19. 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. PMID:24389403

  20. Shortness of Breath

    MedlinePlus

    ... Body & lifestyle changes > Shortness of breath Shortness of breath E-mail to a friend Please fill in ... oxygen your baby gets. Causes of shortness of breath during pregnancy Early pregnancy In the first few ...

  1. What Controls Your Breathing?

    MedlinePlus

    ... To a limited degree, you can change your breathing rate, such as by breathing faster or holding your ... oxygen levels in your blood and change your breathing rate as needed. Sensors in the airways detect lung ...

  2. Breath-Holding Spells

    MedlinePlus

    ... less than a minute before a child regains consciousness and resumes breathing normally. Breath-holding spells can ... spells cause kids to stop breathing and lose consciousness for up to a minute. In the most ...

  3. 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 Chronic obstructive ...

  4. 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

  5. Evaluation of CYP2D6 enzyme activity using a Dextromethorphan Breath Test in Women Receiving Adjuvant Tamoxifen

    PubMed Central

    Safgren, Stephanie L.; Suman, Vera J.; Kosel, Matthew L.; Gilbert, Judith A; Buhrow, Sarah A.; Black, John L.; Northfelt, Donald W.; Modak, Anil S.; Rosen, David; Ingle, James N.; Ames, Matthew M.; Reid, Joel M.; Goetz, Matthew P.

    2015-01-01

    Background In tamoxifen-treated patients, breast cancer recurrence differs according to CYP2D6 genotype and endoxifen steady state concentrations (Endx Css). The 13Cdextromethorphan breath test (DM-BT), labeled with 13C at the O-CH3 moiety, measures CYP2D6 enzyme activity. We sought to examine the ability of the DM-BT to identify known CYP2D6 genotypic poor metabolizers and examine the correlation between DMBT and Endx Css. Methods DM-BT and tamoxifen pharmacokinetics were obtained at baseline (b), 3 month (3m) and 6 months (6m) following tamoxifen initiation. Potent CYP2D6 inhibitors were prohibited. The correlation between bDM-BT with CYP2D6 genotype and Endx Css was determined. The association between bDM-BT (where values ≤0.9 is an indicator of poor in vivo CYP2D6 metabolism) and Endx Css (using values ≤ 11.2 known to be associated with poorer recurrence free survival) was explored. Results 91 patients were enrolled and 77 were eligible. CYP2D6 genotype was positively correlated with b, 3m and 6m DMBT (r ranging from 0.457-0. 60 p < 0.001). Both CYP2D6 genotype (r = 0.47; 0.56, p <.0001), and bDM-BT (r=0.60; 0.54; p<.001) were associated with 3m and 6m Endx Css respectively. Seven of 9 patients (78%) with low (≤11.2 nM) 3m Endx Css also had low DM-BT (≤0.9) including 2/2 CYP2D6 PM/PM and 5/5 IM/PM. In contrast, 1 of 48 pts (2%) with a low DM-BT had Endx Css > 11.2 nM. Conclusions In patients not taking potent CYP2D6 inhibitors, DM-BT was associated with CYP2D6 genotype and 3m and 6 m Endx Css but did not provide better discrimination of Endx Css compared to CYP2D6 genotype alone. Further studies are needed to identify additional factors which alter Endx Css. PMID:25714002

  6. Comparison of the 13C-urea breath test and the endoscopic phenol red mucosal pH test in the quantification of Helicobacter pylori infection loading

    PubMed Central

    Cho, Young-Seok; Jang, Se Na; Kim, Jin-Soo; Son, Hye Suk; Kim, Hyung-Keun; Kim, Byung-Wook; Han, Sok-Won; Choi, Kyu-Yong; Lee, Hae Kyung; Chang, Eun Deok

    2008-01-01

    Background/Aims The 13C-urea breath test (UBT) is a semiquantitative test for measuring Helicobacter pylori infection loading. H. pylori produces ammonia, which elevates the pH of the gastric mucosa and is detectable via endoscopy using a phenol red indicator. We evaluated whether this test could be used to diagnose H. pylori infection and whether phenol red staining was correlated with 13C-UBT results. Methods One hundred and twenty-three patients participated. The UBT was performed after ingestion of a capsule containing urea. A change in 13C-UBT >2‰ was selected as the cutoff value for diagnosing infection. After spraying evenly with a 0.1% phenol red solution, the pH of the gastric mucosal surface was measured using an antimony electrode through the biopsy channel. Results The pH of stained mucosa (6.9±0.4) was significantly higher than that of unstained mucosa (1.9±0.8; p<0.001), and the H. pylori detection rate confirmed via histology was higher in stained versus unstained mucosa (p<0.01). Extensive mucosal staining resulted in a higher detection rate (p<0.001). The UBT produced results were very similar to those obtained via histological detection in stained mucosa (p<0.001). The extent of staining, expressed as a staining score, was positively correlated with the change in 13C-UBT (r=0.426, p<0.001). A significant correlation was also observed between the histologically determined H. pylori density and 13C-UBT results (r=0.674, p<0.001). Conclusions H. pylori infection elevates gastric mucosal surface pH, and endoscopic phenol red staining may be an alternative method for the diagnosis of H. pylori infection. PMID:18787366

  7. 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.

  8. 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.

  9. 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. PMID:25687804

  10. 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

  11. Helicobacter pylori Test

    MedlinePlus

    ... pylori stool antigen test; H. pylori breath test; Urea breath test; CLO test; Rapid urease test (RUT) ... of H. pylori antigen in a stool sample Urea breath test A person drinks a liquid containing ...

  12. 13C-tryptophan breath test detects increased catabolic turnover of tryptophan along the kynurenine pathway in patients with major depressive disorder

    PubMed Central

    Teraishi, Toshiya; Hori, Hiroaki; Sasayama, Daimei; Matsuo, Junko; Ogawa, Shintaro; Ota, Miho; Hattori, Kotaro; Kajiwara, Masahiro; Higuchi, Teruhiko; Kunugi, Hiroshi

    2015-01-01

    Altered tryptophan–kynurenine (KYN) metabolism has been implicated in major depressive disorder (MDD). The l-[1-13C]tryptophan breath test (13C-TBT) is a noninvasive, stable-isotope tracer method in which exhaled 13CO2 is attributable to tryptophan catabolism via the KYN pathway. We included 18 patients with MDD (DSM-IV) and 24 age- and sex-matched controls. 13C-tryptophan (150 mg) was orally administered and the 13CO2/12CO2 ratio in the breath was monitored for 180 min. The cumulative recovery rate during the 180-min test (CRR0–180; %), area under the Δ13CO2-time curve (AUC; %*min), and the maximal Δ13CO2 (Cmax; %) were significantly higher in patients with MDD than in the controls (p = 0.004, p = 0.008, and p = 0.002, respectively). Plasma tryptophan concentrations correlated negatively with Cmax in both the patients and controls (p = 0.020 and p = 0.034, respectively). Our results suggest that the 13C-TBT could be a novel biomarker for detecting a subgroup of MDD with increased tryptophan–KYN metabolism. PMID:26524975

  13. 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

  14. 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. PMID:27579322

  15. 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 (r2 = 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

  16. 46 CFR 197.456 - Breathing supply hoses.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... GENERAL PROVISIONS Commercial Diving Operations Periodic Tests and Inspections of Diving Equipment § 197.456 Breathing supply hoses. (a) The diving supervisor shall insure that— (1) Each breathing supply... for noxious or offensive odor before each diving operation....

  17. 46 CFR 197.456 - Breathing supply hoses.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... GENERAL PROVISIONS Commercial Diving Operations Periodic Tests and Inspections of Diving Equipment § 197.456 Breathing supply hoses. (a) The diving supervisor shall insure that— (1) Each breathing supply... for noxious or offensive odor before each diving operation....

  18. 46 CFR 197.456 - Breathing supply hoses.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... GENERAL PROVISIONS Commercial Diving Operations Periodic Tests and Inspections of Diving Equipment § 197.456 Breathing supply hoses. (a) The diving supervisor shall insure that— (1) Each breathing supply... for noxious or offensive odor before each diving operation....

  19. 46 CFR 197.456 - Breathing supply hoses.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... GENERAL PROVISIONS Commercial Diving Operations Periodic Tests and Inspections of Diving Equipment § 197.456 Breathing supply hoses. (a) The diving supervisor shall insure that— (1) Each breathing supply... for noxious or offensive odor before each diving operation....

  20. 46 CFR 197.456 - Breathing supply hoses.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... GENERAL PROVISIONS Commercial Diving Operations Periodic Tests and Inspections of Diving Equipment § 197.456 Breathing supply hoses. (a) The diving supervisor shall insure that— (1) Each breathing supply... for noxious or offensive odor before each diving operation....

  1. News from the Breath Analysis Summit 2011.

    PubMed

    Corradi, Massimo; Mutti, Antonio

    2012-05-23

    This special section highlights some of the important work presented at the Breath Analysis Summit 2011, which was held in Parma (Italy) from 11 to 14 September 2011. The meeting, which was jointly organized by the International Association for Breath Research and the University of Parma, was attended by more than 250 delegates from 33 countries, and offered 34 invited lectures and 64 unsolicited scientific contributions. The summit was organized to provide a forum to scientists, engineers and clinicians to present their latest findings and to meet industry executives and entrepreneurs to discuss key trends, future directions and technologies available for breath analysis. A major focus was on nitric oxide, exhaled breath condensate, electronic nose, mass spectrometry and newer sensor technologies. Medical applications ranged from asthma and other respiratory diseases to gastrointestinal disease, occupational diseases, critical care and cancer. Most people identify breath tests with breathalysers used by police to estimate ethanol concentration in blood. However, breath testing has far more sophisticated applications. Breath analysis is rapidly evolving as a new frontier in medical testing for disease states in the lung and beyond. Every individual has a breath fingerprint-or 'breathprint'-that can provide useful information about his or her state of health. This breathprint comprises the many thousands of molecules that are expelled with each breath we exhale. Breath research in the past few years has uncovered the scientific and molecular basis for such clinical observations. Relying on mass spectrometry, we have been able to identify many such unique substances in exhaled breath, including gases, such as nitric oxide (NO) and carbon monoxide (CO), and a wide array of volatile organic compounds. Exhaled breath also carries aerosolized droplets that can be collected as an exhaled breath condensate that contains endogenously produced non-volatile compounds. Breath

  2. 13C-methacetin breath test: isotope-selective nondispersive infrared spectrometry in comparison to isotope ratio mass spectrometry in volunteers and patients with liver cirrhosis.

    PubMed

    Adamek, R J; Goetze, O; Boedeker, C; Pfaffenbach, B; Luypaerts, A; Geypens, B

    1999-12-01

    The 13C-methacetin breath test (MBT) has been proposed for the noninvasive evaluation of the hepatic mixed function oxidase activity. Up to now, stable isotope analysis of carbon dioxide of the MBT has been carried out with isotope ratio mass spectrometry (IRMS). The aim of the present study was to test a recently developed isotope-selective nondispersive infrared spectrometer (NDIRS) in comparison to IRMS in healthy volunteers and patients with liver cirrhosis. Ten healthy volunteers (range 22 to 76 years) and ten patients with histologically proven liver cirrhosis (range 47 to 71 years; Child Pugh score A = 5, B = 3, C = 2) were studied. After an overnight fast each subject received 2 mg/kg BW of 13C-methacetin dissolved in 100 ml of tea. Breath samples were obtained before substrate administration and after 5, 10, 15, 20, 30, 40, 50, 60, 80, 100, 120, 150, 180 min. The 13C/12C-ratio was analyzed in each breath sample both by NDIRS (IRIS, Wagner Analysen Technik, Worpswede, Germany) and CF-IRMS (ABCA, Europa Scientific, Crewe, UK). Results were expressed as delta over baseline (DOB [/1000]) and as cumulative percentage doses of 13C recovered (cPDR [%]) at each time interval. Correlations between IRMS and NDIRS were tested by linear regression correlation. For measuring agreement an Altman-Bland-plot was performed. Applying correlation analysis a linear correlation was found (DOB: y = 1.068 +/- 0.0012.x + 2.088 +/- 0.2126, r = 0.98, p < 0.0001; cPDR: y = 1.148 +/- 0.0109.x + 0.569 +/- 0.172; r = 0.99, p < 0.0001). For DOB the mean difference (d) was 2.9/1000 and the standard deviation (SD) of the difference was 2.7/1000. The limits of agreement (d +/- SD) were -2.5/1000 and 8.3/1000. The comparison of DOB- and cPDR-values by NDIRS and IRMS shows a high linear correlation. However, the distance of the limits of agreement is wide. Consequently, the validity of the MBT could be influenced which could make MBT by NDIRS unprecise for exact evaluation of hepatocellular

  3. Breath holding spell

    MedlinePlus

    ... confronted Breath holding spells are more common in children with: Genetic conditions, such as Riley-Day syndrome or Rett syndrome Iron deficiency anemia A family history of breath holding spells (parents ...

  4. Minimizing Shortness of Breath

    MedlinePlus

    ... Top Doctors in the Nation Departments & Divisions Home Health Insights Stress & Relaxation Breathing and Relaxation Minimizing Shortness of Breath ... Management Assess Your Stress Coping Strategies Identifying ... & Programs Health Insights Doctors & Departments Research & Science Education & Training Make ...

  5. Breathing and Relaxation

    MedlinePlus

    ... Top Doctors in the Nation Departments & Divisions Home Health Insights Stress & Relaxation Breathing and Relaxation Breathing and Relaxation Make ... Management Assess Your Stress Coping Strategies Identifying ... & Programs Health Insights Doctors & Departments Research & Science Education & Training Make ...

  6. Rapid CO breath test screening of drugs for protective effects on ribavirin-induced hemolysis in a rabbit model: a pilot study.

    PubMed

    Ma, Yong-Jian; Zhang, Hou-De; Wu, Chuang-Hong; Zhu, Guo-Liang; Ji, Yong-Qiang; Huang, Jia-Liang; Du, Li-Tao; Cao, Ping; Zang, De-Yue; Ji, Kun-Mei

    2016-01-01

    Hemolytic anemia is a major side effect of ribavirin antiviral treatment for chronic hepatitis C. Ribavirin dose reduction may compromise the antiviral response and erythropoietin can take several weeks to alleviate anemia. The purpose of the present study was to screen potentially protective drugs against ribavirin-induced hemolytic anemia in a rabbit model, using our modified CO breath test for measuring erythrocyte (RBC) lifespan, the gold standard diagnostic index of hemolysis. Fifteen rabbits were divided randomly into five groups (N  =  3/group): one vehicle control group, one ribavirin (only)-treated (RBV) group, and three groups initially treated with ribavirin only, followed by a combination of ribavirin with prednisone (RBV  +  Pred), polyene phosphatidyl choline (RBV  +  PPC), or reduced glutathione (RBV  +  GSH). RBC lifespan was calculated from accumulated CO measured in a closed rebreath apparatus, blood volume measured by the Evan's blue dye (EBD) dilution test, and hemoglobin concentration data. The RBC lifespan was normal in the vehicle control group (44-60 d), but reduced significantly in all of the ribavirin-treated groups before the addition of screened drugs (17-35 d). RBC lifespan rebounded significantly with the addition of glutathione, but not with the addition of prednisone or polyene phosphatidyl choline. A similar overall drug effect pattern was seen in the hemoglobin concentration and reticulocyte count data. In conclusion, the results of this pilot study indicate that reduced glutathione can attenuate ribavirin-induced hemolytic anemia, and that the RBC lifespan measured with our modified rapid CO breath test is feasible and reliable for use in animal studies. PMID:27506143

  7. 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.

  8. Breath sounds

    MedlinePlus

    ... Rales can be further described as moist, dry, fine, and coarse. Rhonchi. Sounds that resemble snoring. They ... notice them. The following tests may be done: Analysis of a sputum sample ( sputum culture , sputum Gram ...

  9. Fundamentals of breath malodour.

    PubMed

    Sanz, M; Roldán, S; Herrera, D

    2001-11-15

    Breath malodour is a condition that has health and social implications. The origin of breath malodour problems are related to both systemic and oral conditions. The advice of dental professionals for treatment of this condition occurs with regularity since 90% of breath odor problems emanate from the oral cavity. This paper provides a comprehensive review of the etiology of breath odor, its prevalence, diagnosis, and treatment strategies for the condition. PMID:12167916

  10. What Causes Bad Breath?

    MedlinePlus

    ... I Help a Friend Who Cuts? What Causes Bad Breath? KidsHealth > For Teens > What Causes Bad Breath? Print A A A Text Size en ... Qué es lo que provoca el mal aliento? Bad breath, or halitosis , can be a major problem, ...

  11. 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

  12. 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

  13. Beware Postpartum Shortness of Breath

    PubMed Central

    Akpinar, Guleser; Ipekci, Afsin; Gulen, Bedia; Ikizceli, Ibrahim

    2015-01-01

    Peripartum cardiomyopathy (PPCM) is one of the potentially life-threatening complications of pregnancy. We report a case of a 36-year-old female patient who presented with shortness of breath, swelling of feet after giving birth to triplets, and her tests revealed that left ventricle is dilated with its diameter on the borderline and she had EF 35% with advanced systolic dysfunction. Anterior wall and septum were severely hypokinetic. In the presence of these findings, the patient was evaluated as PPCM. PPCM must be considered in the differential diagnosis of a patient presenting with shortness of breath and swelling of feet, which are also common in pregnancy. PMID:26649031

  14. Beware Postpartum Shortness of Breath.

    PubMed

    Akpinar, Guleser; Ipekci, Afsin; Gulen, Bedia; Ikizceli, Ibrahim

    2015-01-01

    Peripartum cardiomyopathy (PPCM) is one of the potentially life-threatening complications of pregnancy. We report a case of a 36-year-old female patient who presented with shortness of breath, swelling of feet after giving birth to triplets, and her tests revealed that left ventricle is dilated with its diameter on the borderline and she had EF 35% with advanced systolic dysfunction. Anterior wall and septum were severely hypokinetic. In the presence of these findings, the patient was evaluated as PPCM. PPCM must be considered in the differential diagnosis of a patient presenting with shortness of breath and swelling of feet, which are also common in pregnancy. PMID:26649031

  15. 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. PMID:24682160

  16. Stool microbiome reveals diverse bacterial ureases as confounders of oral urea breath testing for Helicobacter pylori and Mycobacterium tuberculosis in Bamako, Mali.

    PubMed

    Maiga, Mamoudou; Cohen, Keira; Baya, Bocar; Srikrishna, Geetha; Siddiqui, Sophia; Sanogo, Moumine; Somboro, Anou M; Diarra, Bassirou; Diallo, Mariam H; Mazumdar, Varun; Yoder, Christian; Orsega, Susan; Belson, Michael; Kassambara, Hamadoun; Goita, Drissa; Murphy, Robert L; Dao, Sounkalo; Polis, Michael; Diallo, Souleymane; Timmins, Graham S; Dodd, Lori; Earl, Ashlee M; Bishai, William R

    2016-01-01

    Detection of bacterial urease activity has been utilized successfully to diagnose Helicobacter pylori (H. pylori). While Mycobacterium tuberculosis (M. tuberculosis) also possesses an active urease, it is unknown whether detection of mycobacterial urease activity by oral urease breath test (UBT) can be exploited as a rapid point of care biomarker for tuberculosis (TB) in humans. We enrolled 34 individuals newly diagnosed with pulmonary TB and 46 healthy subjects in Bamako, Mali and performed oral UBT, mycobacterial sputum culture and H. pylori testing. Oral UBT had a sensitivity and specificity (95% CI) of 70% (46-88%) and 11% (3-26%), respectively, to diagnose culture-confirmed M. tuberculosis disease among patients without H. pylori, and 100% sensitivity (69-100%) and 11% specificity (3-26%) to diagnose H. pylori among patients without pulmonary TB. Stool microbiome analysis of controls without TB or H. pylori but with positive oral UBT detected high levels of non-H. pylori urease producing organisms, which likely explains the low specificity of oral UBT in this setting and in other reports of oral UBT studies in Africa. PMID:27532494

  17. 13C urea breath test for Helicobacter pylori: Determination of the optimal cut-off point in a Canadian community population

    PubMed Central

    Mauro, Marina; Radovic, Vladimir; Zhou, Pengfei; Wolfe, Melanie; Kamath, Markad; Bercik, Premsyl; Croitoru, Ken; Armstrong, David

    2006-01-01

    AIM: To determine the test characteristics and the optimal cut-off point for the 13C urea breath test (13C UBT) in a Canadian community laboratory setting. METHODS: Of 2232 patients (mean age ± SD: 51±21 years, 56% female) who completed a 13C UBT, 1209 were tested to evaluate the primary diagnosis of Helicobacter pylori infection and 1023 were tested for confirmation of eradication following treatment. Cluster analysis was performed on the 13C UBT data to determine the optimal cut-off point and the risk of false-positive and false-negative results. Additionally, 176 patients underwent endoscopic biopsy to allow validation of the sensitivity and specificity of the 13C UBT against histology and microbiology using the calculated cut-off point. RESULTS: The calculated cut-off points were 3.09 δ‰ for the whole study population (n=2232), 3.09 δ‰ for the diagnosis group (n=1209) and 2.88 δ‰ for the post-treatment group (n=1023). When replacing the calculated cut-off points by a practical cut-off point of 3.0 δ‰, the risk of false-positive and false-negative results was lower than 2.3%. The 13C UBT showed 100% sensitivity and 98.5% specificity compared with histology and microbiology (n=176) for the diagnosis of active H pylori infection. CONCLUSIONS: The 13C UBT is an accurate, noninvasive test for the diagnosis of H pylori infection and for confirmation of cure after eradication therapy. The present study confirms the validity of a cutoff point of 3.0 δ‰ for the 13C UBT when used in a large Canadian community population according to a standard protocol. PMID:17171195

  18. Cost effectiveness analysis of population-based serology screening and 13C-Urea breath test for Helicobacter pylori to prevent gastric cancer: A markov model

    PubMed Central

    Xie, Feng; Luo, Nan; Lee, Hin-Peng

    2008-01-01

    AIM: To compare the costs and effectiveness of no screening and no eradication therapy, the population-based Helicobacter pylori (H pylori) serology screening with eradication therapy and 13C-Urea breath test (UBT) with eradication therapy. METHODS: A Markov model simulation was carried out in all 237 900 Chinese males with age between 35 and 44 from the perspective of the public healthcare provider in Singapore. The main outcome measures were the costs, number of gastric cancer cases prevented, life years saved, and quality-adjusted life years (QALYs) gained from screening age to death. The uncertainty surrounding the cost-effectiveness ratio was addressed by one-way sensitivity analyses. RESULTS: Compared to no screening, the incremental cost-effectiveness ratio (ICER) was $16 166 per life year saved or $13 571 per QALY gained for the serology screening, and $38 792 per life year saved and $32 525 per QALY gained for the UBT. The ICER was $477 079 per life year saved or $390 337 per QALY gained for the UBT compared to the serology screening. The cost-effectiveness of serology screening over the UBT was robust to most parameters in the model. CONCLUSION: The population-based serology screening for H pylori was more cost-effective than the UBT in prevention of gastric cancer in Singapore Chinese males. PMID:18494053

  19. Pre-treatment urea breath test results predict the efficacy of Helicobacter pylori eradication therapy in patients with active duodenal ulcers

    PubMed Central

    Lai, Yung-Chih; Yang, Jyh-Chin; Huang, Shih-Hung

    2004-01-01

    AIM: To evaluate the association of pre-treatment 13C-urea breath test (UBT) results with H pylori density and efficacy of eradication therapy in patients with active duodenal ulcers. METHODS: One hundred and seventeen consecutive outpatients with active duodenal ulcer and H pylori infection were recruited. H pylori density was histologically graded according to the Sydney system. Each patient received lansoprazole (30 mg b.i.d.), clarithromycin (500 mg b.i.d.) and amoxicillin (1 g b.i.d.) for 1 week. According to pre-treatment UBT values, patients were allocated into low ( < 16‰), intermediate (16‰-35‰), and high ( > 35‰) UBT groups. RESULTS: A significant correlation was found between pre-treatment UBT results and H pylori density (P < 0.001). H pylori eradication rates were 94.9%, 94.4% and 81.6% in the low, intermediate and high UBT groups, respectively (per protocol analysis, P = 0.11). When patients were assigned into two groups (UBT results ≤ 35‰ and > 35‰), the eradication rates were 94.7% and 81.6%, respectively (P = 0.04). CONCLUSION: The intragastric bacterial load of H pylori can be evaluated by UBT, and high pre-treatment UBT results can predict an adverse outcome of eradication therapy. PMID:15052680

  20. Developmental changes of lactose malabsorption in normal Chinese children: a study using breath hydrogen test with a physiological dose of lactose.

    PubMed

    Ting, C W; Hwang, B; Wu, T C

    1988-01-01

    The malabsorption of a physiological dose of lactose (0.5 g/kg body weight) was studied in 726 healthy Chinese children, ranging in age from 3 to 18 years, using the breath hydrogen test. The prevalence of lactose malabsorption was found to increase with age; it occurred in less than 15% of preschool-age children and in approximately 45% of younger school-age and 60% of older school-age children. Approximately 70% of adolescents measured showed malabsorption. The critical period of change was from 6 to 7 years of age, with the lactose malabsorption rate rising abruptly from 12 to 43%. The incidence of lactose intolerance in teenagers and adolescents was 27 and 33%, respectively. The great majority of them had only dull abdominal pain. No case of lactose intolerance was seen in children less than 9 years of age. These results indicated that preschool Chinese children can absorb a physiological dose of lactose (equivalent to the average amount of milk consumed daily) without any adverse effects. In contrast, one half of school-age children and two thirds of adolescents were malabsorbers. PMID:3199271

  1. 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. PMID:18566138

  2. 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.

  3. Simulated breath waveform control

    NASA Technical Reports Server (NTRS)

    Bartlett, R. G.; Hendricks, C. M.; Morison, W. B.

    1972-01-01

    Subsystem was developed which provides twelve waveform controls to breath drive mechanism. Twelve position, magnetically actuated rotary switch is connected to one end of crankshaft drive, such that it makes one complete revolution for each simulated breath. Connections with common wired point are included in modifications made to standard motor speed controller.

  4. Breath holding spell

    MedlinePlus

    ... children with: Genetic conditions, such as Riley-Day syndrome or Rett syndrome Iron deficiency anemia A family history of breath ... Editorial team. Related MedlinePlus Health Topics Breathing Problems Rett Syndrome Browse the Encyclopedia A.D.A.M., Inc. ...

  5. 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

  6. Upper limb kinematic differences between breathing and non-breathing conditions in front crawl sprint swimming.

    PubMed

    McCabe, Carla B; Sanders, Ross H; Psycharakis, Stelios G

    2015-11-26

    The purpose of this study was to determine whether the breathing action in front crawl (FC) sprint swimming affects the ipsilateral upper limb kinematics relative to a non-breathing stroke cycle (SC). Ten male competitive swimmers performed two 25m FC sprints: one breathing to their preferred side (Br) and one not breathing (NBr). Both swim trials were performed through a 6.75m(3) calibrated space and recorded by six gen-locked JVC KY32 CCD cameras. A paired t-test was used to assess statistical differences between the trials, with a confidence level of p<0.05 accepted as significant. Swimmers were slower (3%) when breathing. Within the entry phase, swimmers had a slower COM horizontal velocity (3.3%), less shoulder flexion (8%), abduction (33%) and roll (4%) when breathing. The pull phase was longer in duration (14%) swimmers had a shallower hand path (11%), less shoulder abduction (11%), a slower hand vertical acceleration (30%) and slower centre of mass (COM) horizontal velocity (3%) when breathing. In the push phase, swimmers had a smaller elbow range of motion (ROM) (38%), faster backwards hand speed (25%) and faster hand vertical acceleration (33%) when breathing. Swimmers rolled their shoulders more (12%) in the recovery phase when breathing. This study confirms that swim performance is compromised by the inclusion of taking a breath in sprint FC swimming. It was proposed that swimmers aim to orient their ipsilateral shoulder into a stronger position by stretching and rolling the shoulders more in the entry phase whilst preparing to take a breath. Swimmers should focus on lengthening the push phase by extending the elbow more and not accelerating the hand too quickly upwards when preparing to inhale. PMID:26456423

  7. Changes in cytochrome P4501A activity during development in common tern chicks fed polychlorinated biphenyls, as measured by the caffeine breath test

    SciTech Connect

    Feyk, L.A.; Giesy, J.P.; Bosveld, A.T.C.; Van den Berg, M.

    2000-03-01

    Cytochrome P4501A (CYPIA) activity is often used as a biomarker of exposure of wildlife to polyhalogenated diaromatic hydrocarbons and is usually measured ex vivo in liver tissue. A caffeine breath test (CBT) with radiolabeled substrate ({sup 14}C-caffeine) was used to measure in vivo CYP1A activity twice during development in 14 common tern (Sterna hirundo) chicks treated with polyhalogenated diaromatic hydrocarbons. Tern hatchlings were fed fish spiked with 3,3{prime}, 4,4{prime},5-pentachlorobiphenyl (PCB 126) and 2,2{prime},4,4{prime},5,5{prime}-hexachlorobiphenyl (PCB 153) such that the diet contained an average of 23, 99, or 561 pg of 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents per gram of fish for 21 d. Sixteen additional common tern chicks were similarly dosed with polyhalogenated diaromatic hydrocarbons but were not subjected to the CBT procedure. In weeks 1 and 2, caffeine N-demethylation and ethoxyresorufin-O-deethylation activity on day 21 were elevated in birds that received the greatest PCB dose. There was less constitutive and greater induction of ethoxyresorufin-O-deethylation activity than caffeine N-demethylation. The {sup 14}C-CBT was less invasive than the ethoxyresorufin-O-deethylase assay. Only one morphological parameter differed significantly between CBT subjects and no-CBT subjects fed the same level of PCBs. Bursa weight was significantly less in control CBT subjects than in control no-CBT subjects, but bursa weights did not differ among CBT and no-CBT birds from the two PCB treatment groups. No alterations of survival or growth occurred in CBT subjects compared with no-CBT subjects.

  8. Breathing difficulties - first aid

    MedlinePlus

    ... a high altitude Blood clot in the lung Collapsed lung (pneumothorax) Heart attack Injury to the neck, chest wall, ... cavity with each breath. This can cause a collapsed lung . Bandage the wound with plastic wrap, a plastic ...

  9. Breathing - slowed or stopped

    MedlinePlus

    ... can occur with obstructive sleep apnea, for example. Prolonged apnea means a person has stopped breathing. If ... that requires immediate medical attention and first aid. Prolonged apnea with no heart activity in a person ...

  10. Shortness-of-Breath

    MedlinePlus

    ... can lead to shortness of breath include anxiety, panic attacks, anemia and even constipation. The experience of shortness ... are used to treat patients with anxiety or panic attacks. Other commonly used drugs include bronchodilators to widen ...

  11. Shortness of Breath

    MedlinePlus

    ... deep breath, which usually results in retention of carbon dioxide and not enough oxygen in blood (obesity hypoventilation ... for anemia), and oximetry or blood oxygen or carbon dioxide levels. Your doctor also may obtain a chest ...

  12. Air-Breathing Rocket Engines

    NASA Technical Reports Server (NTRS)

    1998-01-01

    This photograph depicts an air-breathing rocket engine prototype in the test bay at the General Applied Science Lab facility in Ronkonkoma, New York. 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 Space Transportation 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.

  13. 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

  14. A chlorate candle/lithium hydroxide personal breathing apparatus

    NASA Technical Reports Server (NTRS)

    Martin, F. E.

    1972-01-01

    A portable coal mine rescue and survival equipment is reported that consists of a chlorate candle with a lithium hydroxide carbon-dioxide absorbent for oxygen generation, a breathing bag and tubing to conduct breathing to and from the man. A plastic hood incorporating a mouth piece for communication provides also eye protection and prevents inhalation through the nose. Manned testing of a prototype system demonstrated the feasibility of this closed circuit no-maintenance breathing apparatus that provides for good voice communication.

  15. Automatic Recognition of Breathing Route During Sleep Using Snoring Sounds

    NASA Astrophysics Data System (ADS)

    Mikami, Tsuyoshi; Kojima, Yohichiro

    This letter classifies snoring sounds into three breathing routes (oral, nasal, and oronasal) with discriminant analysis of the power spectra and k-nearest neighbor method. It is necessary to recognize breathing route during snoring, because oral snoring is a typical symptom of sleep apnea but we cannot know our own breathing and snoring condition during sleep. As a result, about 98.8% classification rate is obtained by using leave-one-out test for performance evaluation.

  16. Predisposing factors for positive D-Xylose breath test for evaluation of small intestinal bacterial overgrowth: A retrospective study of 932 patients

    PubMed Central

    Schatz, Richard A; Zhang, Qing; Lodhia, Nilesh; Shuster, Jonathan; Toskes, Phillip P; Moshiree, Baharak

    2015-01-01

    AIM: To investigate, in the largest cohort to date, patient characteristics and associated risk factors for developing small intestinal bacterial overgrowth (SIBO) using the D-Xylose breath test (XBT). METHODS: We performed a retrospective cross-sectional study to analyze patient characteristics who underwent the XBT for evaluation of SIBO. Diagnostic testing with the XBT was performed based on a clinical suspicion for SIBO in patients with symptoms of bloating, abdominal pain, abdominal distension, weight loss, diarrhea, and/or constipation. Consecutive electronic medical records of 932 patients who completed the XBT at the University of Florida between 2005 and 2009 were reviewed. A two-way Analysis of Variance (ANOVA) was used to test for several associations including age, gender, and body mass index (BMI) with a +XBT. A two-way ANOVA was also performed to control for the differences and interaction with age and between genders. A similar analysis was repeated for BMI. Associations between medical conditions and prior surgical histories were conducted using the Mantel-Haenszel method for 2 by 2 contingency tables, stratified for gender. Reported odds ratio estimates reflect the odds of the prevalence of a condition within the +XBT group to that of the -XBT group. P values of less than 0.05 (two-sided) were considered statistically significant. RESULTS: In the 932 consecutive eligible subjects studied, 513 had a positive XBT. A positive association was found between female gender and a positive XBT (P = 0.0025), and females with a positive test were, on average, greater than 5 years older than those with a negative test (P = 0.024). The mean BMI of positive XBT subjects was normal (24.5) and significantly lower than the subjects with a negative XBT (29.5) (P = 0.0050). A positive XBT was associated with gastroesophageal reflux disease (GERD) (OR = 1.35; 95%CI: 1.02-1.80, P = 0.04), peptic ulcer disease (PUD) (OR = 2.61; 95%CI: 1.48-4.59, P < 0.01), gastroparesis

  17. A miniature optical breathing sensor

    PubMed Central

    Mathew, Jinesh; Semenova, Yuliya; Farrell, Gerald

    2012-01-01

    We demonstrate a novel miniature optical breathing sensor based on an Agarose infiltrated photonic crystal fiber interferometer. The sensor detects the variation in relative humidity that occurs between inhaled and exhaled breath. The sensor interrogation system can determine the breathing pattern in real time and can also predict the breathing rate and the breathing status during respiration. The sensor is suitable for monitoring patients during a magnetic resonance imaging scan where use of sedatives and anesthetics necessitates breathing monitoring; electronic sensors are not suitable in such an environment and a visual observation of the patient's respiratory efforts is often difficult. PMID:23243581

  18. Breathing: Rhythmicity, Plasticity, Chemosensitivity

    PubMed Central

    Feldman, Jack L.; Mitchell, Gordon S.; Nattie, Eugene E.

    2010-01-01

    Breathing is a vital behavior that is particularly amenable to experimental investigation. We review recent progress on three problems of broad interest. (i) Where and how is respiratory rhythm generated? The preBötzinger Complex is a critical site, whereas pacemaker neurons may not be essential. The possibility that coupled oscillators are involved is considered. (ii) What are the mechanisms that underlie the plasticity necessary for adaptive changes in breathing? Serotonin-dependent long-term facilitation following intermittent hypoxia is an important example of such plasticity, and a model that can account for this adaptive behavior is discussed. (iii) Where and how are the regulated variables CO2 and pH sensed? These sensors are essential if breathing is to be appropriate for metabolism. Neurons with appropriate chemosensitivity are spread throughout the brainstem; their individual properties and collective role are just beginning to be understood. PMID:12598679

  19. Breathing pattern and exercise endurance time after exhausting cycling or breathing.

    PubMed

    Spengler, C M; Knöpfli-Lenzin, C; Birchler, K; Trapletti, A; Boutellier, U

    2000-03-01

    The aim of the present study was to investigate whether the changes in breathing pattern that frequently occur towards the end of exhaustive exercise (i.e., increased breathing frequency, fb, with or without decreased tidal volume) may be caused by the respiratory work itself rather than by leg muscle work. Eight healthy, trained subjects performed the following three sessions in random order: (A) two sequential cycling endurance tests at 78% peak O2 consumption (VO2peak) to exhaustion (A1, A2); (B) isolated, isocapnic hyperpnea (B1) at a minute ventilation (VE) and an exercise duration similar to that attained during a preliminary cycling endurance test at 78% VO2peak, followed by a cycling endurance test at 78% VO2peak (B2); (C) isolated, isocapnic hyperpnea (C1) at a VE at least 20% higher than that of the preliminary cycling test and the same exercise duration as the preliminary cycling test, followed by a cycling endurance test at 78% VO2peak (C2). Neither of the two isocapnic hyperventilation tasks (B1 or C1) affected either the breathing pattern or the endurance times of the subsequent cycling tests. Only cycling test A2 was significantly shorter [mean (SD) 26.5 (8.3) min] than tests A1 [41.0(9.0) min], B2 [41.9 (6.0) min], and C2 [42.0 (7.5) min]. In addition, compared to test A1, only the breathing pattern of test A2 was significantly different [i.e., VE: + 10.5 (7.6) 1 min(-1), and fb: + 12.1 (8.5) breaths min(-1)], in contrast to the breathing patterns of cycling tests B2 [VE: -2.5 (6.2) 1 min(-1), f(b): +0.2 (3.6) breaths min(-1)] and C2 [VE: -3.0 (7.0) 1 min(-1), fb: +0.6 (6.1) breaths min(-1)]. In summary, these results suggest that the changes in breathing pattern that occur towards the end of an exhaustive exercise test are a result of changes in the leg muscles rather than in the respiratory muscles themselves. PMID:10751097

  20. Measurement of nitric oxide in human exhaled breath

    SciTech Connect

    Gordon, S.M.; Spicer, C.W.; Ollison, W.M.

    1997-12-31

    This project was initiated to confirm the reliability of nitric oxide (NO) measurement in the breath matrix, using two different analytical techniques - ozone and luminol chemiluminescence - and to corroborate literature reports of elevated breath NO values. To measure peak oral and nasal NO levels, subjects performed slow vital capacity and breath holding maneuvers directly into the monitors through the mouth and the nose, respectively. Additional measurements were made using normal breathing techniques. Initial interferent tests indicate that measured NO signals are real and are not confounded by measurement artifacts. Similar results were obtained using the two independent analytical methods in dry or humid air. The NO signal was unaffected by maximum concentrations of potential breath interferents, such as sulfur compounds and alkenes. The measured breath NO concentrations were greater than typical room air levels and differed significantly with the breathing technique used. During these tests room air averaged 4-5 ppb NO. Peak oral NO levels were 4.3 {+-} 1.5 ppb during a slow vital capacity maneuver and 8.0 {+-} 5.0 ppb during a breath holding maneuver. By contrast, higher peak nasal NO levels were measured for both slow vital capacity (17.8 {+-} 7.8 ppb) and breath holding maneuvers (45.4 {+-} 29.5 ppb).

  1. Influence of Continuous Table Motion on Patient Breathing Patterns

    SciTech Connect

    Wilbert, Juergen; Baier, Kurt; Richter, Anne; Herrmann, Christian; Ma Lei; Flentje, Michael; Guckenberger, Matthias

    2010-06-01

    Purpose: To investigate the influence of continuous table motion on patient breathing patterns for compensation of moving targets by a robotic treatment couch. Methods and Materials: Fifteen volunteers were placed on a robotic treatment couch, and the couch was moved on different breathing-correlated and -uncorrelated trajectories. External abdominal breathing motion of the patients was measured using an infrared camera system. The influence of table motion on breathing range and pattern was analyzed. Results: Continuous table motion was tolerated well by all test persons. Volunteers reacted differently to table motion. Four test persons showed no change of breathing range and pattern. Increased irregular breathing was observed in 4 patients; however, irregularity was not correlated with table motion. Only 4 test persons showed an increase in mean breathing amplitude of more than 2mm during motion of the couch. The mean cycle period decreased by more than 1 s for 2 test persons only. No abrupt changes in amplitude or cycle period could be observed. Conclusions: The observed small changes in breathing patterns support the application of motion compensation by a robotic treatment couch.

  2. Breath Examiner Specialist Instructor Training Institute. Final Report.

    ERIC Educational Resources Information Center

    Dunlap and Associates, Inc., Darien, CT.

    Five regional training institutes were held in the spring of 1972 to develop a cadre to teach the National Highway Traffic Safety Administration curriculum package, "Basic Training Program for Breath Examiner Specialist." Emphasis of the institutes was on the development of teaching skills, rather than breath testing skills. Enrollees were drawn…

  3. 49 CFR 40.265 - What happens when an employee is unable to provide a sufficient amount of breath for an alcohol...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... a sufficient amount of breath for an alcohol test? 40.265 Section 40.265 Transportation Office of... sufficient amount of breath for an alcohol test? (a) If an employee does not provide a sufficient amount of breath to permit a valid breath test, you must take the steps listed in this section. (b) As the BAT...

  4. 49 CFR 40.265 - What happens when an employee is unable to provide a sufficient amount of breath for an alcohol...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... a sufficient amount of breath for an alcohol test? 40.265 Section 40.265 Transportation Office of... sufficient amount of breath for an alcohol test? (a) If an employee does not provide a sufficient amount of breath to permit a valid breath test, you must take the steps listed in this section. (b) As the BAT...

  5. 49 CFR 40.265 - What happens when an employee is unable to provide a sufficient amount of breath for an alcohol...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... a sufficient amount of breath for an alcohol test? 40.265 Section 40.265 Transportation Office of... sufficient amount of breath for an alcohol test? (a) If an employee does not provide a sufficient amount of breath to permit a valid breath test, you must take the steps listed in this section. (b) As the BAT...

  6. 49 CFR 40.265 - What happens when an employee is unable to provide a sufficient amount of breath for an alcohol...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... a sufficient amount of breath for an alcohol test? 40.265 Section 40.265 Transportation Office of... sufficient amount of breath for an alcohol test? (a) If an employee does not provide a sufficient amount of breath to permit a valid breath test, you must take the steps listed in this section. (b) As the BAT...

  7. 49 CFR 40.265 - What happens when an employee is unable to provide a sufficient amount of breath for an alcohol...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... a sufficient amount of breath for an alcohol test? 40.265 Section 40.265 Transportation Office of... sufficient amount of breath for an alcohol test? (a) If an employee does not provide a sufficient amount of breath to permit a valid breath test, you must take the steps listed in this section. (b) As the BAT...

  8. The fast exercise drive to breathe.

    PubMed

    Duffin, James

    2014-02-01

    This paper presents a personal view of research into the exercise drive to breathe that can be observed to act immediately to increase breathing at the start of rhythmic exercise. It is based on a talk given at the Experimental Biology 2013 meeting in a session entitled 'Recent advances in understanding mechanisms regulating breathing during exercise'. This drive to breathe has its origin in a combination of central command, whereby voluntary motor commands to the exercising muscles produce a concurrent respiratory drive, and afferent feedback, whereby afferent information from the exercising muscles affects breathing. The drive at the start and end of rhythmic exercise is proportional to limb movement frequency, and its magnitude decays as exercise continues so that the immediate decrease of ventilation at the end of exercise is about 60% of the immediate increase at the start. With such evidence for the effect of this fast drive to breathe at the start and end of rhythmic exercise, its existence during exercise is hypothesised. Experiments to test this hypothesis have, however, provided debatable evidence. A fast drive to breathe during both ramp and sine wave changes in treadmill exercise speed and grade appears to be present in some individuals, but is not as evident in the general population. Recent sine-wave cycling experiments show that when cadence is varied sinusoidally the ventilation response lags by about 10 s, whereas when pedal loading is varied ventilation lags by about 30 s. It therefore appears that limb movement frequency is effective in influencing ventilation during exercise as well as at the start and end of exercise. PMID:23940383

  9. Life and Breath

    ERIC Educational Resources Information Center

    Ellis, Helen D.

    1974-01-01

    This article describes a public education program combining the screening process and a follow-up program for teaching victims of emphysema and other respiratory diseases how to better their living condition through proper breathing, avoidance of air pollutants and cigarette smoking, and taking better care of themselves physically. (PD)

  10. Metabolic breath analyzer

    NASA Technical Reports Server (NTRS)

    Perry, C. L.

    1971-01-01

    Instrument measures metabolic breathing rate and dynamics of human beings in atmospheres ranging from normal air to 100 percent oxygen at ambient pressures from 14.7 to 3.0 psia. Measurements are made at rest or performing tasks up to maximum physical capacity under either zero or normal gravity.

  11. Firefighter's Breathing System

    NASA Technical Reports Server (NTRS)

    Mclaughlan, P. B.; Giorgini, E. A.; Sullivan, J. L.; Simmonds, M. R.; Beck, E. J.

    1976-01-01

    System, based on open-loop demand-type compressed air concept, is lighter and less bulky than former systems, yet still provides thirty minutes of air supply. Comfort, visibility, donning time, and breathing resistance have been improved. Apparatus is simple to recharge and maintain and is comparable in cost to previously available systems.

  12. INTERMITTENT POSITIVE PRESSURE BREATHING

    EPA Science Inventory

    Efficacy of long-term intermittent positive pressure breathing (IPPB) treatment when used as an adjunct to the overall care of ambulatory outpatients with chronic obstructive pulmonary disease. The evaluation compared the use of IPPB with use of a powered nebulizer.

  13. Breathing Like a Fish

    ERIC Educational Resources Information Center

    Katsioloudis, Petros J.

    2010-01-01

    Being able to dive and breathe underwater has been a challenge for thousands of years. In 1980, Fuji Systems of Tokyo developed a series of prototype gills for divers as a way of demonstrating just how good its membranes are. Even though gill technology has not yet reached the point where recipients can efficiently use implants to dive underwater,…

  14. Oronasal breathing during exercise.

    PubMed

    Saibene, F; Mognoni, P; Lafortuna, C L; Mostardi, R

    1978-12-15

    The shift from nasal to oronasal breathing (ONBS) has been observed on 73 subjects with two independent methods. A first group of 63 subjects exercising on a bicycle ergometer at increasing work load (98--196 W) has been observed. On 35 subjects the highest value of ventilation attained with nasal breathing was 40.2 +/- 9.41 . min-1 S.D. Ten subjects breathed through the mouth at all loads, while 5 never opened the mouth. On 13 subjects it was not possible to make reliable measurements. On a second group of 10 subjects utilizing a different techniques which did not need a face mask, the ventilation at which one changes the pattern of breathing was found to be 44.2 +/- 13.51 . min-1 S.D. On the same subjects nasal resistance did not show any correlation with ONBS. It is concluded that ONBS is not solely determined by nasal resistance, though an indirect effect due to hypoventilation and hence to changes in alveolar air composition cannot be ruled out. It is likely that ONBS is also influenced by psychological factors. PMID:569826

  15. Breath Analysis in Disease Diagnosis: Methodological Considerations and Applications

    PubMed Central

    Lourenço, Célia; Turner, Claire

    2014-01-01

    Breath analysis is a promising field with great potential for non-invasive diagnosis of a number of disease states. Analysis of the concentrations of volatile organic compounds (VOCs) in breath with an acceptable accuracy are assessed by means of using analytical techniques with high sensitivity, accuracy, precision, low response time, and low detection limit, which are desirable characteristics for the detection of VOCs in human breath. “Breath fingerprinting”, indicative of a specific clinical status, relies on the use of multivariate statistics methods with powerful in-built algorithms. The need for standardisation of sample collection and analysis is the main issue concerning breath analysis, blocking the introduction of breath tests into clinical practice. This review describes recent scientific developments in basic research and clinical applications, namely issues concerning sampling and biochemistry, highlighting the diagnostic potential of breath analysis for disease diagnosis. Several considerations that need to be taken into account in breath analysis are documented here, including the growing need for metabolomics to deal with breath profiles. PMID:24957037

  16. Exhaled Breath Analysis in Heart Failure.

    PubMed

    Marcondes-Braga, Fabiana G; Batista, Guilherme Lopes; Bacal, Fernando; Gutz, Ivano

    2016-08-01

    Heart failure (HF) is a clinical condition that presents high morbidity and mortality and is one of the main reasons for hospital admissions all over the world. Although biochemical processes that occur in the body during heart failure are known, this syndrome is still associated to poor prognosis. Exhaled breath analysis has emerged as a promising noninvasive tool in different clinical conditions and, recently, it has been also tested in patients with HF. This review presents the main breath HF biomarkers, which reflect metabolic changes that occur in this complex syndrome. It also discusses the diagnostic and prognostic value of exhaled breath compounds for HF and makes a short description of the main technologies involved in this analysis. Some perspectives on the area are presented as well. PMID:27287200

  17. Crew equipment applications - Firefighter's Breathing System.

    NASA Technical Reports Server (NTRS)

    Smith, W. L.

    1973-01-01

    The Firefighter's Breathing System (FBS) represents a significant step in applying NASA's crew equipment technologists and technologies to civilian sector problems. This paper describes the problem, the utilization of user-design committees as a forum for development of design goals, the design of the FBS, and the field test program to be conducted.

  18. Applied breath analysis: an overview of the challenges and opportunities in developing and testing sensor technology for human health monitoring in aerospace and clinical applications

    PubMed Central

    Hunter, Gary W; Dweik, Raed A

    2010-01-01

    The aerospace industry requires the development of a range of chemical sensor technologies for such applications as leak detection, emission monitoring, fuel leak detection, environmental monitoring, and fire detection. A family of chemical sensors are being developed based on micromachining and microfabrication technology to fabricate microsensors with minimal size, weight, and power consumption, and the use of nanomaterials and structures to develop sensors with improved stability combined with higher sensitivity. However, individual sensors are limited in the amount of information that they can provide in environments that contain multiple chemical species. Thus, sensor arrays are being developed to address detection needs in such multi-species environments. These technologies and technical approaches have direct relevance to breath monitoring for clinical applications. This paper gives an overview of developing cutting-edge sensor technology and possible barriers to new technology implementation. This includes lessons learned from previous microsensor development, recent work in development of a breath monitoring system, and future directions in the implementation of cutting edge sensor technology. Clinical applications and the potential impact to the biomedical field of miniaturized smart gas sensor technology are discussed. PMID:20622933

  19. Tests for H. pylori

    MedlinePlus

    Peptic ulcer disease - H. pylori ; PUD - H. pylori ... There are several methods to test for H. pylori infection. Breath Test (Carbon Isotope-urea Breath Test, or UBT) Up to 2 weeks before the test, you need to stop taking ...

  20. Mapleson's Breathing Systems

    PubMed Central

    Kaul, Tej K; Mittal, Geeta

    2013-01-01

    Mapleson breathing systems are used for delivering oxygen and anaesthetic agents and to eliminate carbon dioxide during anaesthesia. They consist of different components: Fresh gas flow, reservoir bag, breathing tubes, expiratory valve, and patient connection. There are five basic types of Mapleson system: A, B, C, D and E depending upon the different arrangements of these components. Mapleson F was added later. For adults, Mapleson A is the circuit of choice for spontaneous respiration where as Mapleson D and its Bains modifications are best available circuits for controlled ventilation. For neonates and paediatric patients Mapleson E and F (Jackson Rees modification) are the best circuits. In this review article, we will discuss the structure of the circuits and functional analysis of various types of Mapleson systems and their advantages and disadvantages. PMID:24249884

  1. Emergency Response Breathing Apparatus

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Aerospace Design & Development, Inc.'s (ADD's) SCAMP was developed under an SBIR contract through Kennedy Space Center. SCAMP stands for Supercritical Air Mobility Pack. The technology came from the life support fuel cell support systems used for the Apollo and Space Shuttle programs. It uses supercritical cryogenic air and is able to function in microgravity environments. SCAMP's self-contained breathing apparatus(SCBA) systems are also ground-based and can provide twice as much air than traditional SCBA's due to its high-density capacity. The SCAMP system was designed for use in launch pad emergency rescues. ADD also developed a protective suit for use with SCAMP that is smaller and lighter system than the old ones. ADD's SCAMP allows for body cooling and breathing from the supercritical cryogenic air, requiring no extra systems. The improvement over the traditional SCBA allows for a reduction of injuries, such as heat stress, and makes it easier for rescuers to save lives.

  2. A fully integrated standalone portable cavity ringdown breath acetone analyzer

    NASA Astrophysics Data System (ADS)

    Sun, Meixiu; Jiang, Chenyu; Gong, Zhiyong; Zhao, Xiaomeng; Chen, Zhuying; Wang, Zhennan; Kang, Meiling; Li, Yingxin; Wang, Chuji

    2015-09-01

    Breath analysis is a promising new technique for nonintrusive disease diagnosis and metabolic status monitoring. One challenging issue in using a breath biomarker for potential particular disease screening is to find a quantitative relationship between the concentration of the breath biomarker and clinical diagnostic parameters of the specific disease. In order to address this issue, we need a new instrument that is capable of conducting real-time, online breath analysis with high data throughput, so that a large scale of clinical test (more subjects) can be achieved in a short period of time. In this work, we report a fully integrated, standalone, portable analyzer based on the cavity ringdown spectroscopy technique for near-real time, online breath acetone measurements. The performance of the portable analyzer in measurements of breath acetone was interrogated and validated by using the certificated gas chromatography-mass spectrometry. The results show that this new analyzer is useful for reliable online (online introduction of a breath sample without pre-treatment) breath acetone analysis with high sensitivity (57 ppb) and high data throughput (one data per second). Subsequently, the validated breath analyzer was employed for acetone measurements in 119 human subjects under various situations. The instrument design, packaging, specifications, and future improvements were also described. From an optical ringdown cavity operated by the lab-set electronics reported previously to this fully integrated standalone new instrument, we have enabled a new scientific tool suited for large scales of breath acetone analysis and created an instrument platform that can even be adopted for study of other breath biomarkers by using different lasers and ringdown mirrors covering corresponding spectral fingerprints.

  3. Association between halitosis and mouth breathing in children

    PubMed Central

    Motta, Lara Jansiski; Bachiega, Joanna Carolina; Guedes, Carolina Cardoso; Laranja, Lorena Tristão; Bussadori, Sandra Kalil

    2011-01-01

    OBJECTIVE: To determine whether there is a correlation between halitosis and mouth breathing in children. STUDY DESIGN: Fifty-five children between 3 and 14 years of age were divided into two groups (nasal and mouth breathing) for the assessment of halitosis. A descriptive analysis was conducted on the degree of halitosis in each group. The chi-square test was used for comparison between groups, with a 5% level of significance. RESULTS: There was a significantly greater number of boys with the mouth-breathing pattern than girls. A total of 23.6% of the participants had no mouth odor, 12.7% had mild odor, 12.7% had moderate odor and 50.9% had strong odor. There was a statistically significant association between halitosis and mouth breathing. CONCLUSIONS: The occurrence of halitosis was high among the children evaluated, and there was a statistically significant association between halitosis and mouth breathing. PMID:21808855

  4. Validation of a new mixing chamber system for breath-by-breath indirect calorimetry.

    PubMed

    Kim, Do-Yeon; Robergs, Robert Andrew

    2012-02-01

    Limited validation research exists for applications of breath-by-breath systems of expired gas analysis indirect calorimetry (EGAIC) during exercise. We developed improved hardware and software for breath-by-breath indirect calorimetry (NEW) and validated this system as well as a commercial system (COM) against 2 methods: (i) mechanical ventilation with known calibration gas, and (ii) human subjects testing for 5 min each at rest and cycle ergometer exercise at 100 and 175 W. Mechanical calibration consisted of medical grade and certified calibration gas ((4.95% CO(2), 12.01% O(2), balance N(2)), room air (20.95% O(2), 0.03% CO(2), balance N(2)), and 100% nitrogen), and an air flow turbine calibrated with a 3-L calibration syringe. Ventilation was mimicked manually using complete 3-L calibration syringe manouvers at a rate of 10·min(-1) from a Douglas bag reservoir of calibration gas. The testing of human subjects was completed in a counterbalanced sequence based on 5 repeated tests of all conditions for a single subject. Rest periods of 5 and 10 min followed the 100 and 175 W conditions, respectively. COM and NEW had similar accuracy when tested with known ventilation and gas fractions. However, during human subjects testing COM significantly under-measured carbon dioxide gas fractions, over-measured oxygen gas fractions and minute ventilation, and resulted in errors to each of oxygen uptake, carbon dioxide output, and respiratory exchange ratio. These discrepant findings reveal that controlled ventilation and gas fractions are insufficient to validate breath-by-breath, and perhaps even time-averaged, systems of EGAIC. The errors of the COM system reveal the need for concern over the validity of commercial systems of EGAIC. PMID:22300357

  5. Probing plasmonic breathing modes optically

    SciTech Connect

    Krug, Markus K. Reisecker, Michael; Hohenau, Andreas; Ditlbacher, Harald; Trügler, Andreas; Hohenester, Ulrich; Krenn, Joachim R.

    2014-10-27

    The confinement of surface plasmon modes in flat nanoparticles gives rise to plasmonic breathing modes. With a vanishing net dipole moment, breathing modes do not radiate, i.e., they are optically dark. Having thus escaped optical detection, breathing modes were only recently revealed in silver nanodisks with electron energy loss spectroscopy in an electron microscope. We show that for disk diameters >200 nm, retardation induced by oblique optical illumination relaxes the optically dark character. This makes breathing modes and thus the full plasmonic mode spectrum accessible to optical spectroscopy. The experimental spectroscopy data are in excellent agreement with numerical simulations.

  6. Online sample conditioning for portable breath analyzers.

    PubMed

    Prabhakar, Amlendu; Iglesias, Rodrigo A; Shan, Xiaonan; Xian, Xiaojun; Zhang, Lihua; Tsow, Francis; Forzani, Erica S; Tao, Nongjian

    2012-08-21

    Various innovative chemical sensors have been developed in recent years to sense dangerous substances in air and trace biomarkers in breath. However, in order to solve real world problems, the sensors must be equipped with efficient sample conditioning that can, e.g., control the humidity, which is discussed much less in the literature. To meet the demand, a miniaturized mouthpiece was developed for personal breath analyzers. A key function of the mouthpiece is to condition the humidity in real breath samples without changing the analyte concentrations and introducing substantial backpressure, which is achieved with optimized packing of desiccant particles. Numerical simulations were carried out to determine the performance of the mouthpiece in terms of various controllable parameters, such as the size, density, and geometry of the packing. Mouthpieces with different configurations were built and tested, and the experimental data validated the simulation findings. A mouthpiece with optimized performance reducing relative humidity from 95% (27,000 ppmV) to 29% (8000 ppmV) whereas retaining 92% nitric oxide (50 ppbV to 46 ppbV) was built and integrated into a hand-held exhaled nitric oxide sensor, and the performance of exhaled nitric oxide measurement was in good agreement with the gold standard chemiluminescence technique. Acetone, carbon dioxide, oxygen, and ammonia samples were also measured after passing through the desiccant mouthpiece using commercial sensors to examine wide applicability of this breath conditioning approach. PMID:22812638

  7. Nocturnal periodic breathing in primary pulmonary hypertension.

    PubMed

    Schulz, R; Baseler, G; Ghofrani, H A; Grimminger, F; Olschewski, H; Seeger, W

    2002-04-01

    Cheyne-Stokes respiration is frequently observed in congestive heart failure. Among other factors, prolongation of circulation time, hypocapnia and hypoxia are thought to underlie this sleep-related breathing disorder. Primary pulmonary hypertension (PPH) is also characterized by reduced cardiac output and blood gas alterations. Therefore, the aim of the present study was to determine whether a nocturnal periodic breathing (PB) occurs in PPH. A total of 20 consecutive patients with PPH who had been admitted for pharmacological investigation of pulmonary vasoreactivity were investigated by lung function testing, right heart catheterization and full-night attended polysomnography. PB was detected in six patients (30%) (mean +/- SEM: apnoea/hypopnoea index 37 +/- 5 h(-1); arterial oxygen saturation was <90% during 56 +/- 6.5% of total sleep time). The patients with PB had more severe haemodynamic impairment than those without. They also had a more marked reduction in the pulmonary diffusion capacity and greater arterial hypoxia. PB was markedly improved or even eradicated by nasal oxygen during the night. Periodic breathing occurs in patients with advanced primary pulmonary hypertension and can be reversed by nocturnal nasal oxygen. The clinical and prognostic significance of periodic breathing in primary pulmonary hypertension needs to be determined by further studies. PMID:11998995

  8. Online sample conditioning for portable breath analyzers

    PubMed Central

    Prabhakar, Amlendu; Iglesias, Rodrigo A.; Xian, Xiaojun; Zhang, Lihua; Tsow, Francis; Forzani, Erica S.; Tao, Nongjian

    2013-01-01

    Various innovative chemical sensors have been developed in recent years to sense dangerous substances in air and trace biomarkers in breath. However, in order to solve real world problems, the sensors must be equipped with efficient sample conditioning that can, e.g., control the humidity, which is much less discussed in literatures. To meet the demand, a miniaturized mouthpiece was developed for personal breath analyzers. A key function of the mouthpiece is to condition the humidity in real breath samples without changing the analyte concentrations and introducing substantial backpressure, which is achieved with optimized packing of desiccant particles. Numerical simulations were carried out to determine the performance of the mouthpiece in terms of various controllable parameters, such as the size, density and geometry of the packing. Mouthpieces with different configurations were built and tested, and the experimental data validated the simulation findings. A mouthpiece with optimized performance reducing relative humidity from 95% (27,000 ppmV) to 29% (8000 ppmV) whereas retaining 92% nitric oxide (50ppbV to 46ppbV) was built and integrated into a handheld exhaled nitric oxide sensor, and the performance of exhaled nitric oxide measurement was in good agreement with the gold standard chemiluminescence technique. Acetone, carbon dioxide, nitric oxide, oxygen and ammonia samples were also measured after passing through the desiccant mouthpiece using commercial sensors to examine wide applicability of this breath conditioning approach. PMID:22812638

  9. Production of egg proteins, enriched with L-leucine-13C1, for the study of protein assimilation in humans using the breath test technique.

    PubMed

    Evenepoel, P; Hiele, M; Luypaerts, A; Geypens, B; Buyse, J; Decuypere, E; Rutgeerts, P; Ghoos, Y

    1997-02-01

    Protein assimilation and metabolism studies are hindered by the lack of an adequate oral tracer, i.e., labeled proteins. We present a new and easily reproducible methodology for producing large amounts of egg proteins labeled with L-leucine-13C1. Laying hens were fed a 0.2% leucine-deficient food supplemented with 0.2% L-leucine-13C1 (99 atom %). At plateau, eggs containing highly enriched proteins were obtained. The 13C content of egg white relative to the total C content was 1.3371 atom %, corresponding to delta = 206%. The overall tracer recovery in egg proteins was high (40.2%), making this method financially attractive as well. Accurately measurable levels of 13CO2 in breath were obtained after ingestion of a physiological load of labeled egg white proteins. Thus, egg proteins with sufficient 13C enrichment and applicable for human protein assimilation and metabolism kinetic studies were produced in an easily reproducible and highly efficient manner. PMID:9039835

  10. BREATHE to Understand©

    ERIC Educational Resources Information Center

    Swisa, Maxine

    2015-01-01

    BREATHE is an acronym for Breathe, Reflect, Empathize, Accept, Thank, Hearten, Engage. The addition of Understand allows for a holistic approach to living a healthy and balanced life both inside and outside the classroom. This paper took form as a result of my personal, spiritual journey, as well as my teaching practice. I noticed that the…

  11. Patient's breath controls comfort devices

    NASA Technical Reports Server (NTRS)

    Schrader, M.; Carpenter, B.; Nichols, C. D.

    1972-01-01

    Patient assist system for totally disabled persons was developed which permits a person, so paralyzed as to be unable to move, to activate by breathing, a call system to summon assistance, turn the page of a book, ajust his bed, or do any one of a number of other things. System consists of patient assist control and breath actuated switch.

  12. How and When Do Insects Rely on Endogenous Protein and Lipid Resources during Lethal Bouts of Starvation? A New Application for 13C-Breath testing.

    PubMed

    McCue, Marshall D; Guzman, R Marena; Passement, Celeste A; Davidowitz, Goggy

    2015-01-01

    Most of our understanding about the physiology of fasting and starvation comes from studies of vertebrates; however, for ethical reasons, studies that monitor vertebrates through the lethal endpoint are scant. Insects are convenient models to characterize the comparative strategies used to cope with starvation because they have diverse life histories and have evolved under the omnipresent challenge of food limitation. Moreover, we can study the physiology of starvation through its natural endpoint. In this study we raised populations of five species of insects (adult grasshoppers, crickets, cockroaches, and larval beetles and moths) on diets labeled with either 13C-palmitic acid or 13C-leucine to isotopically enrich the lipids or the proteins in their bodies, respectively. The insects were allowed to become postabsorptive and then starved. We periodically measured the δ13C of the exhaled breath to characterize how each species adjusted their reliance on endogenous lipids and proteins as energy sources. We found that starving insects employ a wide range of strategies for regulating lipid and protein oxidation. All of the insects except for the beetle larvae were capable of sharply reducing reliance on protein oxidation; however, this protein sparing strategy was usually unsustainable during the entire starvation period. All insects increased their reliance on lipid oxidation, but while some species (grasshoppers, cockroaches, and beetle larvae) were still relying extensively on lipids at the time of death, other species (crickets and moth larvae) allowed rates of lipid oxidation to return to prestarvation levels. Although lipids and proteins are critical metabolic fuels for both vertebrates and insects, insects apparently exhibit a much wider range of strategies for rationing these limited resources during starvation. PMID:26465334

  13. Testing the efficacy of Yoga as a Complementary Therapy for Smoking Cessation: Design and Methods of the BreathEasy trial

    PubMed Central

    Bock, Beth C; Rosen, Rochelle K.; Fava, Joseph L.; Gaskins, Ronnesia B.; Jennings, Ernestine; Thind, Herpreet; Carmody, James; Dunsiger, Shira I; Gidron, Naama; Becker, Bruce M.; Marcus, Bess H.

    2014-01-01

    Smokers trying to quit encounter many challenges including nicotine withdrawal symptoms, cigarette craving, increased stress and negative mood and concern regarding weight gain. These phenomena make it difficult to successfully quit smoking. Studies in non-smoking populations show that yoga reduces stress and negative mood and improves weight control. By increasing mindfulness we anticipate that yoga may also improve smokers’ ability to cope with the negative symptoms associated with quitting. Yoga may also improve cognitive deliberation which is needed to make effective choices and avoid smoking in tempting situations. The BreathEasy study is a rigorous, randomized controlled clinical trial examining the efficacy of Iyengar yoga as a complementary therapy to cognitive-behavioral therapy for smoking cessation. All participants are given an 8-week program of smoking cessation classes, and are randomized to either twice weekly yoga (Yoga) or twice-weekly health and wellness classes which serve as a control for contact and participant burden (CTL). Assessments are conducted at baseline, 8 weeks, 3, 6, and 12 months follow up. The primary outcome is prolonged abstinence using an intention-to-treat approach. Multiple internal and external audits using blind data collection are employed to ensure treatment fidelity and reliability of study results. To understand why yoga may be more effective than CTL, we will examine mechanisms of action (i.e., mediators) underlying intervention efficacy. We will examine maintenance of yoga practice and smoking status at each follow up. Focus groups and interviews will be used to enrich our understanding of the relationship of yoga practice and smoking abstinence. PMID:24937018

  14. How and When Do Insects Rely on Endogenous Protein and Lipid Resources during Lethal Bouts of Starvation? A New Application for 13C-Breath testing

    PubMed Central

    McCue, Marshall D.; Guzman, R. Marena; Passement, Celeste A.; Davidowitz, Goggy

    2015-01-01

    Most of our understanding about the physiology of fasting and starvation comes from studies of vertebrates; however, for ethical reasons, studies that monitor vertebrates through the lethal endpoint are scant. Insects are convenient models to characterize the comparative strategies used to cope with starvation because they have diverse life histories and have evolved under the omnipresent challenge of food limitation. Moreover, we can study the physiology of starvation through its natural endpoint. In this study we raised populations of five species of insects (adult grasshoppers, crickets, cockroaches, and larval beetles and moths) on diets labeled with either 13C-palmitic acid or 13C-leucine to isotopically enrich the lipids or the proteins in their bodies, respectively. The insects were allowed to become postabsorptive and then starved. We periodically measured the δ13C of the exhaled breath to characterize how each species adjusted their reliance on endogenous lipids and proteins as energy sources. We found that starving insects employ a wide range of strategies for regulating lipid and protein oxidation. All of the insects except for the beetle larvae were capable of sharply reducing reliance on protein oxidation; however, this protein sparing strategy was usually unsustainable during the entire starvation period. All insects increased their reliance on lipid oxidation, but while some species (grasshoppers, cockroaches, and beetle larvae) were still relying extensively on lipids at the time of death, other species (crickets and moth larvae) allowed rates of lipid oxidation to return to prestarvation levels. Although lipids and proteins are critical metabolic fuels for both vertebrates and insects, insects apparently exhibit a much wider range of strategies for rationing these limited resources during starvation. PMID:26465334

  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, 2011 CFR

    2011-10-01

    ... drop the device on the floor), you must discard the device and conduct a new test using a new device... before the test. (iii) You must note on the “Remarks” line of the ATF the reason for the new test. (Note: You may continue using the same ATF with which you began the test.) (iv) You must offer the...

  16. Rapid shallow breathing index.

    PubMed

    Karthika, Manjush; Al Enezi, Farhan A; Pillai, Lalitha V; Arabi, Yaseen M

    2016-01-01

    Predicting successful liberation of patients from mechanical ventilation has been a focus of interest to clinicians practicing in intensive care. Various weaning indices have been investigated to identify an optimal weaning window. Among them, the rapid shallow breathing index (RSBI) has gained wide use due to its simple technique and avoidance of calculation of complex pulmonary mechanics. Since its first description, several modifications have been suggested, such as the serial measurements and the rate of change of RSBI, to further improve its predictive value. The objective of this paper is to review the utility of RSBI in predicting weaning success. In addition, the use of RSBI in specific patient populations and the reported modifications of RSBI technique that attempt to improve the utility of RSBI are also reviewed. PMID:27512505

  17. Breathing zone air sampler

    DOEpatents

    Tobin, John

    1989-01-01

    A sampling apparatus is provided which comprises a sampler for sampling air in the breathing zone of a wearer of the apparatus and a support for the sampler preferably in the form of a pair of eyeglasses. The sampler comprises a sampling assembly supported on the frame of the eyeglasses and including a pair of sample transport tubes which are suspended, in use, centrally of the frame so as to be disposed on opposite sides of the nose of the wearer and which each include an inlet therein that, in use, is disposed adjacent to a respective nostril of the nose of the wearer. A filter holder connected to sample transport tubes supports a removable filter for filtering out particulate material in the air sampled by the apparatus. The sample apparatus is connected to a pump for drawing air into the apparatus through the tube inlets so that the air passes through the filter.

  18. Breathing rhythms and emotions.

    PubMed

    Homma, Ikuo; Masaoka, Yuri

    2008-09-01

    Respiration is primarily regulated for metabolic and homeostatic purposes in the brainstem. However, breathing can also change in response to changes in emotions, such as sadness, happiness, anxiety or fear. Final respiratory output is influenced by a complex interaction between the brainstem and higher centres, including the limbic system and cortical structures. Respiration is important in maintaining physiological homeostasis and co-exists with emotions. In this review, we focus on the relationship between respiration and emotions by discussing previous animal and human studies, including studies of olfactory function in relation to respiration and the piriform-amygdala in relation to respiration. In particular, we discuss oscillations of piriform-amygdala complex activity and respiratory rhythm. PMID:18487316

  19. Rapid shallow breathing index

    PubMed Central

    Karthika, Manjush; Al Enezi, Farhan A.; Pillai, Lalitha V.; Arabi, Yaseen M.

    2016-01-01

    Predicting successful liberation of patients from mechanical ventilation has been a focus of interest to clinicians practicing in intensive care. Various weaning indices have been investigated to identify an optimal weaning window. Among them, the rapid shallow breathing index (RSBI) has gained wide use due to its simple technique and avoidance of calculation of complex pulmonary mechanics. Since its first description, several modifications have been suggested, such as the serial measurements and the rate of change of RSBI, to further improve its predictive value. The objective of this paper is to review the utility of RSBI in predicting weaning success. In addition, the use of RSBI in specific patient populations and the reported modifications of RSBI technique that attempt to improve the utility of RSBI are also reviewed. PMID:27512505

  20. A Ringdown Breath Analyzer for Diabetes Monitoring: Breath Acetone in Diabetic Patients.

    NASA Astrophysics Data System (ADS)

    Wang, Chuji; Mbi, Armstrong; Shepherd, Mark

    2008-03-01

    It is highly desirable for millions of diabetic patients to have a non-blood, non-invasive, point-of-care device for monitoring daily blood glucose (BG) levels and the adequacy of diabetic treatment and control. Cavity ringdown spectroscopy, due to its unique capability of high sensitivity, fast-response, and relatively low cost for instrumentation, has the potential for medical application through non-invasive analysis of breath biomarkers. We report the first ringdown acetone breath analyzer for clinic testing with diabetic outpatients. The instrument was set in a clinic center and 34 outpatients (24 T1D and 10 T2D) were tested during a four-day period. 10 T1D subjects and 15 nondiabetic persons were tested in our laboratory. Three juvenile-onset T1D subjects were selected for a 24-hr monitoring on the variations of breath acetone and simultaneous BG level. In this talk, we present our research findings including the correlations of breath acetone with BG level and A1C.

  1. One-year follow-up study of Helicobacter pylori eradication rate with 13C-urea breath test after 3-d and 7-d rabeprazole-based triple therapy

    PubMed Central

    Wang, Hwang-Huei; Chou, Jen-Wei; Liao, Kuan-Fu; Lin, Zong-Yi; Lai, Hsueh-Chou; Hsu, Chang-Hu; Chen, Chih-Bin

    2005-01-01

    AIM: To investigate the long-term role of a 3-d rabeprazole-based triple therapy in patients with Helicobacter pylori(H pylori)-infected active peptic ulcers. METHODS: We prospectively studied 115 consecutive patients with H pylori-infected active peptic ulcers. H pylori infection was confirmed if any two of H pylori DNA, histology, and rapid urease test were positive. Patients were assigned to either an open-labeled 3-d course of oral amoxicillin 1000 mg b.i.d., clarithromycin 500 mg b.i.d., and rabeprazole 20 mg b.i.d., or 7-d course of oral amoxicillin 1000 mg b.i.d., clarithromycin 500 mg b.i.d., and rabeprazole 20 mg b.i.d. Subsequently, all patients received oral rabeprazole 20 mg once daily until the 8th wk. Three months after therapy, all patients were followed-up endoscopically for the peptic ulcer, H pylori DNA, histology, and rapid urease test. One year after therapy, H pylori infection was tested using the 13C-urea breath test. RESULTS: The ulcer healing rates 3 mo after therapy were 81.0% vs 75.4% for the 3-d and 7-d groups [intention-to-treat (ITT) analysis, P = 0.47] respectively, and 90.4% vs 89.6% for the 3-d and 7-d groups [per-protocol (PP) analysis, P = 0.89] respectively. The eradication rates 3 mo after therapy were 75.9% vs 73.7% for the 3-d and 7-d groups (ITT, P = 0.79) respectively, and 84.6% vs 87.5% for the 3-d and 7-d groups (PP, P = 0.68) respectively. One year after therapy, seventy-five patients returned to receive the 13C-urea breath test, and the eradication rates were 78.4% vs 81.6% in 3-d and 7-d groups (PP, P = 0.73) respectively. CONCLUSION: Our study showed the eradication rates against H pylori infection 3 and 12 mo after triple therapy were not different between the 3-d and 7-d rabeprazole-based groups. Therefore, the 3-d rabeprazole-based triple therapy may be an alternative treatment for peptic ulcers with H pylori infection. PMID:15786549

  2. Ethylene and ammonia traces measurements from the patients' breath with renal failure via LPAS method

    NASA Astrophysics Data System (ADS)

    Popa, C.; Dutu, D. C. A.; Cernat, R.; Matei, C.; Bratu, A. M.; Banita, S.; Dumitras, D. C.

    2011-11-01

    The application of laser photoacoustic spectroscopy (LPAS) for fast and precise measurements of breath biomarkers has opened up new promises for monitoring and diagnostics in recent years, especially because breath test is a non-invasive method, safe, rapid and acceptable to patients. Our study involved assessment of breath ethylene and breath ammonia levels in patients with renal failure receiving haemodialysis (HD) treatment. Breath samples from healthy subjects and from patients with renal failure were collected using chemically inert aluminized bags and were subsequently analyzed using the LPAS technique. We have found out that the composition of exhaled breath in patients with renal failure contains not only ethylene, but also ammonia and gives valuable information for determining efficacy and endpoint of HD. Analysis of ethylene and ammonia traces from the human breath may provide insight into severity of oxidative stress and metabolic disturbances and may ensure optimal therapy and prevention of pathology at patients on continuous HD.

  3. Breathing He-O2 increases ventilation but does not decrease the work of breathing during exercise.

    PubMed

    Babb, T G

    2001-04-01

    We previously observed an increase in minute ventilation (V E) with resistive unloading (He-O2 breathing) in healthy elderly subjects with normal pulmonary function. To investigate the effects of resistive unloading in elderly subjects with mild chronic airflow limitation (FEV(1)/FVC: 61 +/- 4%), we studied 10 elderly men and women 70 +/- 3 yr of age. These subjects performed graded cycle ergometry to exhaustion, once breathing room air and once breathing a He-O2 gas mixture (79% He, 21% O2). V E, pulmonary mechanics, and PET(CO2) were measured during each 1-min increment in work rate. Data were analyzed by paired t test at rest, at ventilatory threshold (VTh), and during maximal exercise. V E was significantly (p < 0.05) increased at VTh (3.4 +/- 4.0 L/min or 12 +/- 15% increase) and maximal exercise (15.2 +/- 9.7 L/min or 22 +/- 13% increase) while breathing He-O2. Concomitant to the increase in V E, PET(CO2) was decreased at all levels (p < 0.01), whereas total work of breathing against the lung was not different. We concluded that V E is increased during He-O2 breathing because of resistive unloading of the airways and the maintenance of the relationship between the work of breathing and exercise work rate. PMID:11316648

  4. Effect of a deep breath on gas mixing and diffusion in the lung.

    PubMed

    Prabhu, M B; Mink, J T; Graham, B L; Cotton, D J

    1990-03-01

    We examined the effect of a previous deep breath on both inert gas mixing and the single breath diffusing capacity (DLCOSB) during submaximal single breath maneuvers in normal subjects. Single breath washouts were performed either immediately after a deep breath or after breathing tidally for 10 min. Maneuvers consisted of inhaling test gas from functional residual capacity to 50% inspiratory capacity and, after either 0 or 6 s of breath holding, exhaling slowly back to residual volume. We measured the Fowler dead space, the Phase III slope of the alveolar plateau of the He washout (delta He/L), the amplitude of the cardiogenic oscillations (Oc), closing capacity, mixing efficiency (Emix) and DLCOSB using the three equation method. For maneuvers immediately after a deep breath we found that delta He/L was steeper and the Oc were larger for washouts with 6 s but not 0 s of breath holding, while Emix was significantly lower and DLCOSB significantly higher for both the 0 s and the 6 s breath holding maneuvers. We conclude that a deep breath increases DLCOSB but simultaneously also increases convective-dependent inhomogeneity in the lung. PMID:2356360

  5. Lateral pharyngeal fat pad pressure during breathing.

    PubMed

    Winter, W C; Gampper, T; Gay, S B; Suratt, P M

    1996-12-01

    The purpose of this study was to test whether pressure in tissue lateral to the upper airway, the lateral pharyngeal fat pad, differs from atmospheric and pharyngeal pressure and whether it changes with breathing. We studied five male pigs by inserting a transducer-tipped catheter into their fat pad space using computed tomography (CT) scan guidance. We measured airflow with a pneumotachograph attached to a face mask and pharyngeal pressure with a balloon catheter. Fat pad pressure correlated positively with airflow and with pharyngeal pressure, decreasing during inspiration and increasing during expiration. Pressure in the fat pad differed from atmospheric pressure, generally exceeding it, and from pharyngeal pressure. We conclude that lateral pharyngeal fat pad pressure differs from atmospheric and pharyngeal pressure and that it changes with breathing. PMID:9085504

  6. Integrated engineering modeling for air breathing rockets

    NASA Astrophysics Data System (ADS)

    Chitilappilly, Lazar T.; Subramanyam, J. D. A.

    An innovative aerodynamic-propulsion-flight integrated modeling is carried out for airbreathing rockets, the propulsion of which has primary dependence on flight conditions. The integrated modeling is highly beneficial for design and analysis of accelerating air breathing rockets characterized by continuously varying flight conditions. The details of the modeling is described; the force accounting, trajectory analysis, solving the flow in the sub-systems (air intake, primary rocket, secondary combustion chamber and secondary nozzle), matching the subsystem flow fields and determining the mode of operation. Operational features are listed of the computer software developed, air breathing integrated design and analysis engineering software. It gives all the propulsion and flight parameters from take-off of the rocket to end of flight and has been instrumental in the design of the research air breathing rocket ABR-200(I). The hundreds of flight performance analyses required for design is possible by the engineering approach adopted for solving the propulsor flow field. The software results are compared with ejector mode and connected pipe mode static tests. The overall validation of the software is achieved by flight tests; the performance predictions have matched exactly with that measured during thee first and second flights of the ABR-200(I).

  7. Evaluation of Exalenz Bioscience's BreathID for Helicobacter pylori detection.

    PubMed

    Broide, Efrat; Shirin, Haim

    2015-03-01

    Carbon-labeled urea breath tests, which have high sensitivity and specificity, are the preferred method used in epidemiological studies, screening dyspeptic patients and assessing eradication or recurrence of Helicobacter pylori infection. The principle of the (13)C-urea breath test relies upon the ability of the H. pylori urease to hydrolyze the orally administered (13)C-urea. The BreathID (Exalenz Bioscience Inc., Union, NJ, USA) provides a competitive solution for breath testing, including unique features such as automatic continuous breath collection and analysis. This is an unattended convenient test, with no human error as the correct part of the breath is collected and patients' assistance is not required. The test results are available in real time at the point of care and enable shortened breath testing procedures. Additionally, several studies showing expanded utility of the BreathID in pediatrics, after therapy and during proton pump inhibitors intake, further support the safety and performance of the BreathID in the diagnosis of H. pylori. PMID:25634297

  8. General practitioners' habits and knowledge in relation to the management of H. pylori-associated dyspepsia and their views about a locally available 13-carbon urea breath test.

    PubMed Central

    Heaney, A; Collins, J S; Watson, P R; Kalin, R M

    2000-01-01

    We report the results of general practitioners' views on Helicobacter pylori-associated dyspepsia and use of screening tests in the community. The use of office serology tests in screening is of concern as independent validation in specialist units has been disappointing. PMID:10750235

  9. Palliative care - shortness of breath

    MedlinePlus

    ... to control shortness of breath: Call your doctor, palliative care team, or hospice nurse for advice Call 911 ... Bicanovsky L. Comfort care: symptom control in the dying. In: Walsh ... . 1st ed. Philadelphia, PA: Elsevier Saunders; 2008:chap 181.

  10. Visualizing Breath using Digital Holography

    NASA Astrophysics Data System (ADS)

    Hobson, P. R.; Reid, I. D.; Wilton, J. B.

    2013-02-01

    Artist Jayne Wilton and physicists Peter Hobson and Ivan Reid of Brunel University are collaborating at Brunel University on a project which aims to use a range of techniques to make visible the normally invisible dynamics of the breath and the verbal and non-verbal communication it facilitates. The breath is a source of a wide range of chemical, auditory and physical exchanges with the direct environment. Digital Holography is being investigated to enable a visually stimulating articulation of the physical trajectory of the breath as it leaves the mouth. Initial findings of this research are presented. Real time digital hologram replay allows the audience to move through holographs of breath-born particles.

  11. Liquid-Air Breathing Apparatus

    NASA Technical Reports Server (NTRS)

    Mills, Robert D.

    1990-01-01

    Compact unit supplies air longer than compressed-air unit. Emergency breathing apparatus stores air as cryogenic liquid instead of usual compressed gas. Intended for firefighting or rescue operations becoming necessary during planned potentially hazardous procedures.

  12. Detection of cancer through exhaled breath: a systematic review

    PubMed Central

    Krilaviciute, Agne; Heiss, Jonathan Alexander; Leja, Marcis; Kupcinskas, Juozas; Haick, Hossam; Brenner, Hermann

    2015-01-01

    Background Timely diagnosis of cancer represents a challenging task; in particular, there is a need for reliable non-invasive screening tools that could achieve high levels of adherence at virtually no risk in population-based screening. In this review, we summarize the current evidence of exhaled breath analysis for cancer detection using standard analysis techniques and electronic nose. Methods Relevant studies were identified searching Pubmed and Web of Science databases until April 30, 2015. Information on breath test performance, such as sensitivity and specificity, was extracted together with volatile compounds that were used to discriminate cancer patients from controls. Performance of different breath analysis techniques is provided for various cancers together with information on methodological issues, such as breath sampling protocol and validation of the results. Results Overall, 73 studies were included, where two-thirds of the studies were conducted on lung cancer. Good discrimination usually required a combination of multiple biomarkers, and area under the receiver operating characteristic curve or accuracy reached levels of 0.9 or higher in multiple studies. In 25% of the reported studies, classification models were built and validated on the same datasets. Huge variability was seen in different aspects among the studies. Conclusions Analyses of exhaled breath yielded promising results, although standardization of breath collection, sample storage and data handling remain critical issues. In order to foster breath analysis implementation into practice, larger studies should be implemented in true screening settings, paying particular attention to standardization in breath collection, consideration of covariates, and validation in independent population samples. PMID:26440312

  13. Standardization of exhaled breath condensate (EBC) collection using a feedback regulated breathing pattern

    EPA Science Inventory

    Collection of exhaled breath condensate (EBC) fluid by cooling of expired breath is a potentially valuable approach for the detection of biomarkers associated with disease or exposure to xenobiotics. EBC is generally collected using unregulated breathing patterns, perceived to el...

  14. A Study of the Effects of Breath Management Instruction on the Breathing Mode, Knowledge of Breathing, and Performance Skills of College-Level Brass Players.

    ERIC Educational Resources Information Center

    Phillips, Kenneth H.; Sehmann, Karin Harfst

    1990-01-01

    Investigates the effectiveness of breathing instruction on the breath management, performance, and knowledge of breathing among college-level brass musicians. Finds that breathing instruction significantly improved the breath management and knowledge of the breathing for the experimental groups and the musical range of the trombone players in the…

  15. Reliability and Determinants of Self-Evaluation of Breathing Questionnaire (SEBQ) Score: A Symptoms-Based Measure of Dysfunctional Breathing.

    PubMed

    Mitchell, A J; Bacon, C J; Moran, R W

    2016-03-01

    Dysfunctional breathing is characterised by an abnormal breathing pattern leading to respiratory symptoms. The 25-item Self Evaluation of Breathing Questionnaire (SEBQ) has been developed to measure breathing-related symptoms and their severity but lacks thorough evaluation. To determine reproducibility, internal consistency and predictors of SEBQ score, 180 participants completed an online SEBQ with additional demographic and lifestyle questions. Two weeks later, 155 of those repeated SEBQ. Test-retest correlation of the SEBQ was high [intraclass correlation coefficient (3, 1) = 0.89; 95 % CI 0.85-0.92]. There was no difference in SEBQ score between test and retest (15.1 (11.6) [mean (SD)] versus 14.7 (12.4); P = 0.4) and the score showed a typical error (standard error of measurement) of 4.0. Internal consistency was high (Cronbach's α = 0.93), and a single factor structure for items was shown. Smoking status, reported respiratory disease, recent respiratory illness and female gender were positively-associated predictors of SEBQ score, and together explained 25.6 % of score variance (P ≤ 0.001). The SEBQ has high test-retest reproducibility and its score may be predicted by current smoking, chronic respiratory disease, recent respiratory illness and female gender, thus may be a useful clinical screening tool for dysfunctional breathing. PMID:26400252

  16. Imposed Work of Breathing for Flow Meters with In-Line versus Flow-Through Technique during Simulated Neonatal Breathing

    PubMed Central

    2015-01-01

    Background The ability to determine airflow during nasal CPAP (NCPAP) treatment without adding dead space or resistance would be useful when investigating the physiologic effects of different NCPAP systems on breathing. The aim of this study was to investigate the effect on pressure stability of different flow measuring devices at the in-line and flow-through position, using simulated neonatal breathing. Methods Six different flow measure devices were evaluated by recording pressure changes and imposed work of breathing for breaths with 16 and 32 ml tidal volumes. The tests were performed initially with the devices in an in line position and with 5 and 10 L/min using flow through technique, without CPAP. The flow meters were then subsequently tested with an Infant Flow CPAP system at 3, 5 and 8 cm H2O pressure using flow through technique. The quality of the recorded signals was compared graphically. Results The resistance of the measuring devices generated pressure swings and imposed work of breathing. With bias flow, the resistance also generated CPAP pressure. Three of the devices had low resistance and generated no changes in pressure stability or CPAP pressure. The two devices intended for neonatal use had the highest measured resistance. Conclusion The importance of pressure stability and increased work of breathing during non-invasive respiratory support are insufficiently studied. Clinical trials using flow-through technique have not focused on pressure stability. Our results indicate that a flow-through technique might be a way forward in obtaining a sufficiently high signal quality without the added effects of rebreathing and increased work of breathing. The results should stimulate further research and the development of equipment for dynamic flow measurements in neonates. PMID:26192188

  17. Understanding Lung Problems: Make Each Breath Healthy

    MedlinePlus

    ... Each Breath Healthy Heath and Aging Understanding Lung Problems—Make Each Breath Healthy Chronic Obstructive Pulmonary Disease ( ... time your likelihood of having a serious lung problem increases, especially if you smoke. Lung problems that ...

  18. Engineering task plan for determining breathing rates in singleshell tanks using tracer gas

    SciTech Connect

    Andersen, J.A.

    1997-04-02

    The testing of single shell tanks to determine breathing rates. Inert tracer gases helium, and sulfur hexafluoride will be injected into the tanks AX-103, BY-105, C-107 and U-103. Periodic samples will be taken over a three month interval to determine actual headspace breathing rates.

  19. Mathematical and statistical approaches for interpreting biomarker compounds in exhaled human breath

    EPA Science Inventory

    The various instrumental techniques, human studies, and diagnostic tests that produce data from samples of exhaled breath have one thing in common: they all need to be put into a context wherein a posed question can actually be answered. Exhaled breath contains numerous compoun...

  20. Assessing and ensuring patient safety during breath-holding for radiotherapy

    PubMed Central

    Green, S; Stevens, A M; Clutton-Brock, T H

    2014-01-01

    Objective: While there is recent interest in using repeated deep inspiratory breath-holds, or prolonged single breath-holds, to improve radiotherapy delivery, breath-holding has risks. There are no published guidelines for monitoring patient safety, and there is little clinical awareness of the pronounced blood pressure rise and the potential for gradual asphyxia that occur during breath-holding. We describe the blood pressure rise during deep inspiratory breath-holding with air and test whether it can be abolished simply by pre-oxygenation and hypocapnia. Methods: We measured blood pressure, oxygen saturation (SpO2) and heart rate in 12 healthy, untrained subjects performing breath-holds. Results: Even for deep inspiratory breath-holds with air, the blood pressure rose progressively (e.g. mean systolic pressure rose from 133 ± 5 to 175 ± 8 mmHg at breakpoint, p < 0.005, and in two subjects, it reached 200 mmHg). Pre-oxygenation and hypocapnia prolonged breath-hold duration and prevented the development of asphyxia but failed to abolish the pressure rise. The pressure rise was not a function of breath-hold duration and was not signalled by any fall in heart rate (remaining at resting levels of 72 ± 2 beats per minute). Conclusion: Colleagues should be aware of the progressive blood pressure rise during deep inspiratory breath-holding that so far is not easily prevented. In breast cancer patients scheduled for breath-holds, we recommend routine screening for heart, cardiovascular, renal and cerebrovascular disease, routine monitoring of patient blood pressure and SpO2 during breath-holding and requesting patients to stop if systolic pressure rises consistently >180 mmHg and or SpO2 falls <94%. Advances in knowledge: There is recent interest in using deep inspiratory breath-holds, or prolonged single breath-holding techniques, to improve radiotherapy delivery. But there appears to be no clinical awareness of the risks to patients from breath

  1. Shortness of Breath

    MedlinePlus

    ... may also order an electrocardiogram (also called an ECG). During this test, your doctor will have you ... down so your heart can be monitored. The ECG machine creates a picture, or tracing, that shows ...

  2. Breathing difficulty - lying down

    MedlinePlus

    ... What other symptoms do you have? The physical exam will include special attention to the heart and lungs ( cardiovascular and respiratory systems). Tests that may be performed include the following: ...

  3. Submarines, Spacecraft, and Exhaled Breath

    EPA Science Inventory

    The International Association of Breath Research (IABR) meetings are an eclectic gathering of researchers in the medical, environmental and instrumentation fields; our focus is on human health as assessed by the measurement and interpretation of trace chemicals in human exhaled b...

  4. Breathing Problems: An Individualized Program.

    ERIC Educational Resources Information Center

    Vodola, Thomas M.

    As one of the components of the Project ACTIVE (All Children Totally Involved Exercising) Teacher Training Model Kit, the manual is designed to enable the educator to organize, conduct, and evaluate individualized-personalized physical education programs for children (prekindergarten through high school) with breathing problems. An introductory…

  5. 21 CFR 868.5620 - Breathing mouthpiece.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Breathing mouthpiece. 868.5620 Section 868.5620...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5620 Breathing mouthpiece. (a) Identification. A breathing mouthpiece is a rigid device that is inserted into a patient's mouth and...

  6. Functional Analysis and Intervention for Breath Holding.

    ERIC Educational Resources Information Center

    Kern, Lee; And Others

    1995-01-01

    A functional analysis of breath-holding episodes in a 7-year-old girl with severe mental retardation and Cornelia-de-Lange syndrome indicated that breath holding served an operant function, primarily to gain access to attention. Use of extinction, scheduled attention, and a picture card communication system decreased breath holding. (Author/SW)

  7. Interactions between breathing rate and low-frequency fluctuations in blood pressure and cardiac intervals.

    PubMed

    Horsman, H M; Peebles, K C; Tzeng, Y C

    2015-10-01

    Evidence derived from spontaneous measures of cardiovagal baroreflex sensitivity (BRS) suggests that slow breathing at 6 breaths/min augments BRS. However, increases in BRS associated with slow breathing may simply reflect the frequency-dependent nature of the baroreflex rather than the modulation of baroreflex function by changes in breathing rate per se. To test this hypothesis we employed a crossover study design (n = 14) wherein breathing rate and systolic arterial blood pressure (SAP) oscillation induced via the application of oscillating lower body negative pressure (OLBNP) were independently varied at fixed frequencies. Breathing rate was controlled at 6 or 10 breaths/min with the aid of a metronome, and SAP oscillations were driven at 0.06 Hz and 0.1 Hz using OLBNP. The magnitudes of SAP and R-R interval (cardiac period) oscillations were quantified using power spectral analysis, and the transfer function gain between SAP and R-R interval was used to estimate BRS. Linear mixed-effects models were used to examine the main effects and interactions between breathing rate and OLBNP frequency. There was no statistical interaction between breathing and OLBNP frequency (P = 0.59), indicating that the effect of breathing rate on BRS did not differ according to OLBNP frequency (and vice versa). Additionally, there was no main effect for breathing rate (P = 0.28). However, we observed a significant main effect for OLBNP frequency (P = 0.01) consistent with the frequency-dependent nature of baroreflex. These findings suggest that increases in spectral indices of BRS reflect the frequency dependence of the baroreflex and are not due to slow breathing per se. PMID:26205543

  8. Changes in breathing while listening to read speech: the effect of reader and speech mode

    PubMed Central

    Rochet-Capellan, Amélie; Fuchs, Susanne

    2013-01-01

    The current paper extends previous work on breathing during speech perception and provides supplementary material regarding the hypothesis that adaptation of breathing during perception “could be a basis for understanding and imitating actions performed by other people” (Paccalin and Jeannerod, 2000). The experiments were designed to test how the differences in reader breathing due to speaker-specific characteristics, or differences induced by changes in loudness level or speech rate influence the listener breathing. Two readers (a male and a female) were pre-recorded while reading short texts with normal and then loud speech (both readers) or slow speech (female only). These recordings were then played back to 48 female listeners. The movements of the rib cage and abdomen were analyzed for both the readers and the listeners. Breathing profiles were characterized by the movement expansion due to inhalation and the duration of the breathing cycle. We found that both loudness and speech rate affected each reader’s breathing in different ways. Listener breathing was different when listening to the male or the female reader and to the different speech modes. However, differences in listener breathing were not systematically in the same direction as reader differences. The breathing of listeners was strongly sensitive to the order of presentation of speech mode and displayed some adaptation in the time course of the experiment in some conditions. In contrast to specific alignments of breathing previously observed in face-to-face dialog, no clear evidence for a listener–reader alignment in breathing was found in this purely auditory speech perception task. The results and methods are relevant to the question of the involvement of physiological adaptations in speech perception and to the basic mechanisms of listener–speaker coupling. PMID:24367344

  9. Neural Mechanisms Underlying Breathing Complexity

    PubMed Central

    Hess, Agathe; Yu, Lianchun; Klein, Isabelle; De Mazancourt, Marine; Jebrak, Gilles; Mal, Hervé; Brugière, Olivier; Fournier, Michel; Courbage, Maurice; Dauriat, Gaelle; Schouman-Clayes, Elisabeth; Clerici, Christine; Mangin, Laurence

    2013-01-01

    Breathing is maintained and controlled by a network of automatic neurons in the brainstem that generate respiratory rhythm and receive regulatory inputs. Breathing complexity therefore arises from respiratory central pattern generators modulated by peripheral and supra-spinal inputs. Very little is known on the brainstem neural substrates underlying breathing complexity in humans. We used both experimental and theoretical approaches to decipher these mechanisms in healthy humans and patients with chronic obstructive pulmonary disease (COPD). COPD is the most frequent chronic lung disease in the general population mainly due to tobacco smoke. In patients, airflow obstruction associated with hyperinflation and respiratory muscles weakness are key factors contributing to load-capacity imbalance and hence increased respiratory drive. Unexpectedly, we found that the patients breathed with a higher level of complexity during inspiration and expiration than controls. Using functional magnetic resonance imaging (fMRI), we scanned the brain of the participants to analyze the activity of two small regions involved in respiratory rhythmogenesis, the rostral ventro-lateral (VL) medulla (pre-Bötzinger complex) and the caudal VL pons (parafacial group). fMRI revealed in controls higher activity of the VL medulla suggesting active inspiration, while in patients higher activity of the VL pons suggesting active expiration. COPD patients reactivate the parafacial to sustain ventilation. These findings may be involved in the onset of respiratory failure when the neural network becomes overwhelmed by respiratory overload We show that central neural activity correlates with airflow complexity in healthy subjects and COPD patients, at rest and during inspiratory loading. We finally used a theoretical approach of respiratory rhythmogenesis that reproduces the kernel activity of neurons involved in the automatic breathing. The model reveals how a chaotic activity in neurons can

  10. Drive mechanism for production of simulated human breath

    NASA Technical Reports Server (NTRS)

    Bartlett, R. G.; Hendricks, C. M.; Lambert, J. W.; Morison, W. B.

    1972-01-01

    Simulated breath drive mechanism was developed as subsystem to breathing metabolic simulator. Mechanism reproduces complete range of human breath rate, breath depth, and breath waveform, as well as independently controlled functional residual capacity. Mechanism was found capable of simulating various individual human breathing characteristics without any changes of parts.

  11. Abdominal breathing manoeuvre reduces passive drag acting on gliding swimmers.

    PubMed

    Maruyama, Yusuke; Yanai, Toshimasa

    2015-01-01

    The purpose of this study was to test the hypothesis that the passive drag acting on a gliding swimmer is reduced if the swimmer adopts an abdominal breathing manoeuvre (expanding the abdominal wall) rather than chest breathing manoeuvre (expanding the rib cage). Eleven male participants participated in this study. A specialised towing machine was used to tow each participant with tension set at various magnitudes and to record time series data of towing velocity. Participants were asked to inhale air by expanding the abdominal wall or the rib cage and to maintain the same body configuration throughout gliding. The steady-state velocity was measured and the coefficient of drag was calculated for each towing trial to compare between the breathing manoeuvres. The results showed that the towing velocity was increased by 0.02 m/s with a towing force of 34.3 N and by 0.06 m/s with a towing force of 98.1 N. The coefficient of drag was reduced by 5% with the abdominal breathing manoeuvre, which was found to be statistically significant (p < 0.05). These results indicate that adopting the abdominal breathing manoeuvre during gliding reduces the passive drag and the hypothesis was supported. PMID:26715235

  12. Waldorf Education: Breathing Creativity

    ERIC Educational Resources Information Center

    Nordlund, Carrie

    2013-01-01

    After 10 years of teaching art in public schools, Carrie Nordlund arrived at a state of query that set in motion her search for alternative approaches to learning. As she was feeling stifled in a seemingly sterile education institution with its overdependence on and pedagogy aimed at standardized tests, she came across a reference to Waldorf…

  13. A Portable Real-Time Ringdown Breath Acetone Analyzer: Toward Potential Diabetic Screening and Management.

    PubMed

    Jiang, Chenyu; Sun, Meixiu; Wang, Zhennan; Chen, Zhuying; Zhao, Xiaomeng; Yuan, Yuan; Li, Yingxin; Wang, Chuji

    2016-01-01

    Breath analysis has been considered a suitable tool to evaluate diseases of the respiratory system and those that involve metabolic changes, such as diabetes. Breath acetone has long been known as a biomarker for diabetes. However, the results from published data by far have been inconclusive regarding whether breath acetone is a reliable index of diabetic screening. Large variations exist among the results of different studies because there has been no "best-practice method" for breath-acetone measurements as a result of technical problems of sampling and analysis. In this mini-review, we update the current status of our development of a laser-based breath acetone analyzer toward real-time, one-line diabetic screening and a point-of-care instrument for diabetic management. An integrated standalone breath acetone analyzer based on the cavity ringdown spectroscopy technique has been developed. The instrument was validated by using the certificated gas chromatography-mass spectrometry. The linear fittings suggest that the obtained acetone concentrations via both methods are consistent. Breath samples from each individual subject under various conditions in total, 1257 breath samples were taken from 22 Type 1 diabetic (T1D) patients, 312 Type 2 diabetic (T2D) patients, which is one of the largest numbers of T2D subjects ever used in a single study, and 52 non-diabetic healthy subjects. Simultaneous blood glucose (BG) levels were also tested using a standard diabetic management BG meter. The mean breath acetone concentrations were determined to be 4.9 ± 16 ppm (22 T1D), and 1.5 ± 1.3 ppm (312 T2D), which are about 4.5 and 1.4 times of the one in the 42 non-diabetic healthy subjects, 1.1 ± 0.5 ppm, respectively. A preliminary quantitative correlation (R = 0.56, p < 0.05) between the mean individual breath acetone concentration and the mean individual BG levels does exist in 20 T1D subjects with no ketoacidosis. No direct correlation is observed in T1D subjects, T2D

  14. Liquid breathing trials and animal studies with a demand-regulated liquid breathing system.

    PubMed

    Moskowitz, G D; Shaffer, T H; Dubin, S E

    1975-01-01

    Experimental results of in vivo animal tests conducted on a demand-regulated liquid breathing system are presented. When a liquid replaces gas as the medium in which oxygen and carbon dioxide are transported, several problems not typical in gas respiration occur. The increased mass and viscosity of a liquid as compared with a gas necessitate some means of mechanical assistance. The lower diffusion rates of gases in liquids as compared with gas rates places several constraints on the design of a mechanically assisted liquid breathing system. The liquid breathing system reported in this study has been designed to be demand-regulated, i.e., the animal has control over cycling the pumps which mechanically assist the circulation of an oxygenated liquid to and from the lungs. This system consists of a gas-operated diaphragm pump, demand controller, liquid regenerator with heater and gas scrubber, and ancillary equipment. A demand controller is described which obtains a control signal from an esophageal balloon catheter in the animal and governs operation of the pneumatically driven diaphragm pump. PMID:1055284

  15. Changes in CYP2C19 enzyme activity evaluated by the [(13)C]-pantoprazole breath test after co-administration of clopidogrel and proton pump inhibitors following percutaneous coronary intervention and correlation to platelet reactivity.

    PubMed

    Harvey, Adrien; Modak, Anil; Déry, Ugo; Roy, Mélanie; Rinfret, Stéphane; Bertrand, Olivier F; Larose, Éric; Rodés-Cabau, Josep; Barbeau, Gérald; Gleeton, Onil; Nguyen, Can Manh; Proulx, Guy; Noël, Bernard; Roy, Louis; Paradis, Jean-Michel; De Larochellière, Robert; Déry, Jean-Pierre

    2016-03-01

    Dual antiplatelet therapy (DAPT) with clopidogrel and aspirin is used for the prevention of cardiovascular events following percutaneous coronary intervention (PCI). These agents increase the risk of gastrointestinal bleeding. To prevent these events, proton pump inhibitors (PPI) are routinely prescribed. It has been reported that with the exception of pantoprazole and dexlanzoprazole, PPIs can impede conversion of clopidogrel by cytochrome P450 2C19 (CYP2C19) to its active metabolite, a critical step required for clopidogrel efficacy. Changes in CYP2C19 enzyme activity (phenotype) and its correlation with platelet reactivity following PPI therapy has not yet been fully described. In this study we attempted to determine if the [ (13)C]-pantoprazole breath test (Ptz-BT) can evaluate changes in CYP2C19 enzyme activity (phenoconversion) following the administration of PPI in coronary artery disease (CAD) patients treated with DAPT after PCI. Thirty (30) days after successful PCI with stent placement, 59 patients enrolled in the Evaluation of the Influence of Statins and Proton Pump Inhibitors on Clopidogrel Antiplatelet Effects (SPICE) trial (ClinicalTrials.gov Identifier: NCT00930670) were recruited to participate in this sub study. Patients were randomized to one of 4 antacid therapies (omeprazole, esomeprazole. pantoprazole or ranitidine). Subjects were administered the Ptz-BT and platelet function was evaluated by vasodilator-stimulated phosphoprotein (VASP) phosphorylation and light transmittance aggregometry before and 30 d after treatment with antacid therapy. Patients randomized to esomeprazole and omeprazole had greater high on-treatment platelet reactivity and lowering of CYP2C19 enzyme activity at Day 60 after 30 d of PPI therapy. Patients randomized to ranitidine and pantoprazole did not show any changes in platelet activity or CYP 2C19 enzyme activity. In patients treated with esomeprazole and omeprazole, changes in CYP2C19 enzyme activity

  16. Changes in breathing pattern upon 100% oxygen in children at early school age.

    PubMed

    Jost, K; Lenherr, N; Singer, F; Schulzke, S M; Frey, U; Latzin, P; Yammine, S

    2016-07-01

    Nitrogen multiple-breath washout (N2MBW) is an increasingly used tidal breathing test in young children to assess ventilation inhomogeneity. However, the test requires 100% oxygen to perform. We aimed to examine the potential influence of pure oxygen on breathing pattern in school-aged children. We performed tidal breathing measurements under room air followed by N2MBW in 16 former preterm children and 24 healthy controls. We compared tidal volume (VT), coefficient of variation of VT (CVVT), respiratory rate (RR), and minute ventilation (VE) between tidal breathing and N2MBW, and between the start and end of tidal breathing. Mean (range) age was 6.8 (5.9, 9.0) years. VT, RR and VE showed no significant change upon oxygen-exposure, while CVVT significantly decreased by 5% (95% CI: 1.2, 9.0; p=0.012). However CVVT was also the only parameter which significantly decreased during tidal breathing. Overall, pure oxygen has no systematic effect on breathing pattern in young school-aged children. N2MBW can reliably be used as tracer gas in this age group. PMID:26970571

  17. Self-contained breathing apparatus

    NASA Technical Reports Server (NTRS)

    Sullivan, J. L.; Giorgini, E. A.; Simmonds, M. R. (Inventor)

    1976-01-01

    A self-contained breathing apparatus with automatic redundant fluid pressure controls and a facemask mounted low pressure whistle alarm is described. The first stage of the system includes pair of pressure regulators connected in parallel with different outlet pressures, both of which reduce the pressure of the stored supply gas to pressures compatible with the second stage breathing demand regulator. A primary regulator in the first stage delivers a low output pressure to the demand regulator. In the event of a failure closed condition of the primary regulator an automatic transfer valve switches on the backup regulator. A warning that the supply pressure has been depleted is also provided by a supply pressure actuated transfer valve which transfers the output of the first stage pressure regulators from the primary to the backup regulator. The alarm is activated in either the failure closed condition or if the supply pressure is reduced to a dangerously low level.

  18. The athlete "out of breath".

    PubMed

    Couto, M; Moreira, A

    2016-03-01

    Athletes often complain about breathing problems. This is a crucial issue due to potential implications not only on their general health, but also on their competing performance. Asthma and exercise-induced bronchoconstriction are prevalent conditions in elite athletes, which leads doctors to rely most of the times on asthma medication to treat athletes feeling "out of breath". However, there are several other conditions that may mimic asthma and cause dyspnea in athletes. Effective treatment of dyspnea requires appropriate identification and treatment of all disorders. Proper knowledge and accurate diagnosis of such entities is mandatory, since asthma medication is not effective in those conditions. Herein we review the most common differential diagnosis of dyspnea in athletes, and describe the diagnostic strategies in order to increase awareness and to improve doctor's confidence on dealing with these patients. PMID:26934737

  19. Breathing Mode in Complex Plasmas

    NASA Astrophysics Data System (ADS)

    Fujioka, K.; Henning, C.; Ludwig, P.; Bonitz, M.; Melzer, A.; Vitkalov, S.

    2007-11-01

    The breathing mode is a fundamental normal mode present in Coulomb systems, and may have utility in identifying particle charge and the Debye length of certain systems. The question remains whether this mode can be extended to strongly coupled Yukawa balls [1]. These systems are characterized by particles confined within a parabolic potential well and interacting through a shielded Coulomb potential [2,3]. The breathing modes for a variety of systems in 1, 2, and 3 dimensions are computed by solving the eigenvalue problem given by the dynamical (Hesse) matrix. These results are compared to theoretical investigations that assume a strict definition for a breathing mode within the system, and an analysis is made of the most fitting model to utilize in the study of particular systems of complex plasmas [1,4]. References [1] T.E. Sheridan, Phys. of Plasmas. 13, 022106 (2006)[2] C. Henning et al., Phys. Rev. E 74, 056403 (2006)[3] M. Bonitz et al., Phys. Rev. Lett. 96, 075001 (2006)[4] C. Henning et al., submitted for publication

  20. Breathing Dynamics in Heteropolymer DNA

    PubMed Central

    Ambjörnsson, Tobias; Banik, Suman K.; Krichevsky, Oleg; Metzler, Ralf

    2007-01-01

    While the statistical mechanical description of DNA has a long tradition, renewed interest in DNA melting from a physics perspective is nourished by measurements of the fluctuation dynamics of local denaturation bubbles by single molecule spectroscopy. The dynamical opening of DNA bubbles (DNA breathing) is supposedly crucial for biological functioning during, for instance, transcription initiation and DNA's interaction with selectively single-stranded DNA binding proteins. Motivated by this, we consider the bubble breathing dynamics in a heteropolymer DNA based on a (2+1)-variable master equation and complementary stochastic Gillespie simulations, providing the bubble size and the position of the bubble along the sequence as a function of time. We utilize new experimental data that independently obtain stacking and hydrogen bonding contributions to DNA stability. We calculate the spectrum of relaxation times and the experimentally measurable autocorrelation function of a fluorophore-quencher tagged basepair, and demonstrate good agreement with fluorescence correlation experiments. A significant dependence of opening probability and waiting time between bubble events on the local DNA sequence is revealed and quantified for a promoter sequence of the T7 phage. The strong dependence on sequence, temperature and salt concentration for the breathing dynamics of DNA found here points at a good potential for nanosensing applications by utilizing short fluorophore-quencher dressed DNA constructs. PMID:17237209

  1. Running and Breathing in Mammals

    NASA Astrophysics Data System (ADS)

    Bramble, Dennis M.; Carrier, David R.

    1983-01-01

    Mechanical constraints appear to require that locomotion and breathing be synchronized in running mammals. Phase locking of limb and respiratory frequency has now been recorded during treadmill running in jackrabbits and during locomotion on solid ground in dogs, horses, and humans. Quadrupedal species normally synchronize the locomotor and respiratory cycles at a constant ratio of 1:1 (strides per breath) in both the trot and gallop. Human runners differ from quadrupeds in that while running they employ several phase-locked patterns (4:1, 3:1, 2:1, 1:1, 5:2, and 3:2), although a 2:1 coupling ratio appears to be favored. Even though the evolution of bipedal gait has reduced the mechanical constraints on respiration in man, thereby permitting greater flexibility in breathing pattern, it has seemingly not eliminated the need for the synchronization of respiration and body motion during sustained running. Flying birds have independently achieved phase-locked locomotor and respiratory cycles. This hints that strict locomotor-respiratory coupling may be a vital factor in the sustained aerobic exercise of endothermic vertebrates, especially those in which the stresses of locomotion tend to deform the thoracic complex.

  2. Exhaled breath analysis and sleep.

    PubMed

    Carpagnano, Giovanna E

    2011-10-15

    It is currently estimated that the economic burden for obstructive sleep apnea syndrome (OSAS) cases not coming to medical attention is steadily increasing, thus making OSAS a major public health concern. For its increasing incidence among the common population, the interest of researchers and clinicians has been recently directed to the study of pathological mechanisms underlying sleep disorders. Current opinion is that airway inflammation and oxidative stress play a crucial role in the pathophysiology of OSAS. Recently there has been increasing interest in the investigation of lungs by non-invasive means measuring the exhaled breath volatile mediators, such as nitric oxide (NO), carbon monoxide (CO), ethane and pentane and finally the non-volatile substances in the liquid phase of exhalate, termed breath condensate. The non-invasiveness of these techniques for the study of airways affected by different respiratory disorders and among those, the OSAS, makes these ideally suited for the evaluation and serial monitoring of patients. Notwithstanding the increasing number of scientific contributions on the use of the exhaled markers in sleep disorders, at the moment, their use is not completely suitable for clinical application. An important contribution to the increase of our knowledge on exhaled markers and for their possible concrete application in clinical practice may come from future studies using proteomics, genomics and metabolomics. In this review, we focus on exhaled breath analysis giving an update on its general aspects, its application in OSAS, and finally its actual clinical applicability and areas for future direction. PMID:22003329

  3. Tensilon test

    MedlinePlus

    ... dummy medicine (inactive placebo) is given during this test. The health care provider gives the medicine through one of your ... fainting or breathing failure. This is why the test is done by a health care provider in a medical setting.

  4. Distress Reduction for Palliative Care Patients and Families With 5-Minute Mindful Breathing: A Pilot Study.

    PubMed

    Beng, Tan Seng; Ahmad, Fazlina; Loong, Lam Chee; Chin, Loh Ee; Zainal, Nor Zuraida; Guan, Ng Chong; Ann, Yee Hway; Li, Lee Mei; Meng, Christopher Boey Chiong

    2016-07-01

    A pilot study was conducted to evaluate the efficacy of 5-minute mindful breathing in distress reduction. Twenty palliative care patients and family caregivers with a distress score ≥4 measured by the Distress Thermometer were recruited and randomly assigned to mindful breathing or "listening" (being listened to). Median distress reductions after 5 minutes were 2.5 for the mindful breathing group and 1.0 for the listening group. A significantly larger reduction in the distress score was observed in the mindful breathing group (Mann-Whitney U test: U = 8.0, n1 = n2 = 10, mean rank1 = 6.30, mean rank2 = 14.70, z = -3.208, P = .001). The 5-minute mindful breathing could be useful in distress reduction in palliative care. PMID:25632044

  5. Differentiation between genetic mutations of breast cancer by breath volatolomics

    PubMed Central

    Hua, Qing-Ling; Pan, Yue-Yin; Kayal, Haneen; Khoury, Kayan; Liu, Hu; Davies, Michael P.A.; Haick, Hossam

    2015-01-01

    Mapping molecular sub-types in breast cancer (BC) tumours is a rapidly evolving area due to growing interest in, for example, targeted therapy and screening high-risk populations for early diagnosis. We report a new concept for profiling BC molecular sub-types based on volatile organic compounds (VOCs). For this purpose, breath samples were collected from 276 female volunteers, including healthy, benign conditions, ductal carcinoma in situ (DCIS) and malignant lesions. Breath samples were analysed by gas chromatography mass spectrometry (GC-MS) and artificially intelligent nanoarray technology. Applying the non-parametric Wilcoxon/Kruskal-Wallis test, GC-MS analysis found 23 compounds that were significantly different (p < 0.05) in breath samples of BC patients with different molecular sub-types. Discriminant function analysis (DFA) of the nanoarray identified unique volatolomic signatures between cancer and non-cancer cases (83% accuracy in blind testing), and for the different molecular sub-types with accuracies ranging from 82 to 87%, sensitivities of 81 to 88% and specificities of 76 to 96% in leave-one-out cross-validation. These results demonstrate the presence of detectable breath VOC patterns for accurately profiling molecular sub-types in BC, either through specific compound identification by GC-MS or by volatolomic signatures obtained through statistical analysis of the artificially intelligent nanoarray responses. PMID:26540569

  6. Guidelines proposal for clinical recognition of mouth breathing children

    PubMed Central

    Pacheco, Maria Christina Thomé; Casagrande, Camila Ferreira; Teixeira, Lícia Pacheco; Finck, Nathalia Silveira; de Araújo, Maria Teresa Martins

    2015-01-01

    INTRODUCTION: Mouth breathing (MB) is an etiological factor for sleep-disordered breathing (SDB) during childhood. The habit of breathing through the mouth may be perpetuated even after airway clearance. Both habit and obstruction may cause facial muscle imbalance and craniofacial changes. OBJECTIVE: The aim of this paper is to propose and test guidelines for clinical recognition of MB and some predisposing factors for SDB in children. METHODS: Semi-structured interviews were conducted with 110 orthodontists regarding their procedures for clinical evaluation of MB and their knowledge about SDB during childhood. Thereafter, based on their answers, guidelines were developed and tested in 687 children aged between 6 and 12 years old and attending elementary schools. RESULTS: There was no standardization for clinical recognition of MB among orthodontists. The most common procedures performed were inefficient to recognize differences between MB by habit or obstruction. CONCLUSIONS: The guidelines proposed herein facilitate clinical recognition of MB, help clinicians to differentiate between habit and obstruction, suggest the most appropriate treatment for each case, and avoid maintenance of mouth breathing patterns during adulthood. PMID:26352843

  7. Exhaled breath analysis: The new interface between medicine and engineering

    PubMed Central

    Mashir, Alquam; Dweik, Raed A.

    2010-01-01

    Exhaled breath testing is becoming an increasingly important non-invasive diagnostic method that can be used in the evaluation of health and disease states in the lung and beyond. Potential advantages of breath tests over other conventional medical tests include their non-invasive nature, low cost, and safety. To advance in this area further, however, there has to be a close collaboration between technical experts and engineers who have devices looking for clinical application(s), the medical experts who have the clinical problems looking for a test/biomarker that can be helpful in diagnosis or monitoring, and industry/commercial experts who can build and commercialize the final product. PMID:20948990

  8. Breathing and sense of self: visuo-respiratory conflicts alter body self-consciousness.

    PubMed

    Adler, Dan; Herbelin, Bruno; Similowski, Thomas; Blanke, Olaf

    2014-11-01

    Bodily self-consciousness depends on the processing of interoceptive and exteroceptive signals. It can be disrupted by inducing signal conflicts. Breathing, at the crossroad between interoception and exteroception, should contribute to bodily self-consciousness. We induced visuo-respiratory conflicts in 17 subjects presented with a virtual body or a parallelepidedal object flashing synchronously or asynchronously with their breathing. A questionnaire detected illusory changes in bodily self-consciousness and breathing agency (the feeling of sensing one's breathing command). Changes in self-location were tested by measuring reaction time during mental ball drop (MBD). Synchronous illumination changed the perceived location of breathing (body: p=0.008 vs. asynchronous; object: p=0.013). It resulted in a significant change in breathing agency, but no changes in self-identification. This was corroborated by prolonged MBD reaction time (body: +0.045s, 95%CI [0.013; 0.08], p=0.007). We conclude that breathing modulates bodily self-consciousness. We also conclude that one can induce the irruption of unattended breathing into consciousness without modifying respiratory mechanics or gas exchange. PMID:25194692

  9. Reprint of "Breathing and sense of self: visuo-respiratory conflicts alter body self-consciousness".

    PubMed

    Adler, Dan; Herbelin, Bruno; Similowski, Thomas; Blanke, Olaf

    2014-12-01

    Bodily self-consciousness depends on the processing of interoceptive and exteroceptive signals. It can be disrupted by inducing signal conflicts. Breathing, at the crossroad between interoception and exteroception, should contribute to bodily self-consciousness. We induced visuo-respiratory conflicts in 17 subjects presented with a virtual body or a parallelepidedal object flashing synchronously or asynchronously with their breathing. A questionnaire detected illusory changes in bodily self-consciousness and breathing agency (the feeling of sensing one's breathing command). Changes in self-location were tested by measuring reaction time during mental ball drop (MBD). Synchronous illumination changed the perceived location of breathing (body: p=0.008 vs. asynchronous; object: p=0.013). It resulted in a significant change in breathing agency, but no changes in self-identification. This was corroborated by prolonged MBD reaction time (body: +0.045s, 95%CI [0.013; 0.08], p=0.007). We conclude that breathing modulates bodily self-consciousness. We also conclude that one can induce the irruption of unattended breathing into consciousness without modifying respiratory mechanics or gas exchange. PMID:25266397

  10. Kidney motion during free breathing and breath hold for MR-guided radiotherapy

    NASA Astrophysics Data System (ADS)

    Stam, Mette K.; van Vulpen, Marco; Barendrecht, Maurits M.; Zonnenberg, Bernard A.; Intven, Martijn; Crijns, Sjoerd P. M.; Lagendijk, Jan J. W.; Raaymakers, Bas W.

    2013-04-01

    Current treatments for renal cell carcinoma have a high complication rate due to the invasiveness of the treatment. With the MRI-linac it may be possible to treat renal tumours non-invasively with high-precision radiotherapy. This is expected to reduce complications. To deliver a static dose distribution, radiation gating will be used. In this study the reproducibility and efficiency of free breathing gating and a breath hold treatment of the kidney was investigated. For 15 patients with a renal lesion the kidney motion during 2 min of free breathing and 10 consecutive expiration breath holds was studied with 2D cine MRI. The variability in kidney expiration position and treatment efficiency for gating windows of 1 to 20 mm was measured for both breathing patterns. Additionally the time trend in free breathing and the variation in expiration breath hold kidney position with baseline shift correction was determined. In 80% of the patients the variation in expiration position during free breathing is smaller than 2 mm. No clinically relevant time trends were detected. The variation in expiration breath hold is for all patients larger than the free breathing expiration variation. Gating on free breathing is, for gating windows of 1 to 5 mm more efficient than breath hold without baseline correction. When applying a baseline correction to the breath hold it increases the treatment efficiency. The kidney position is more reproducible in expiration free breathing than non-guided expiration breath hold. For small gating windows it is also more time efficient. Since free breathing also seems more comfortable for the patients it is the preferred breathing pattern for MRI-Linac treatments of the kidney.

  11. Cardiovascular and Respiratory Effect of Yogic Slow Breathing in the Yoga Beginner: What Is the Best Approach?

    PubMed Central

    Mason, Heather; Vandoni, Matteo; deBarbieri, Giacomo; Codrons, Erwan; Ugargol, Veena; Bernardi, Luciano

    2013-01-01

    Slow breathing increases cardiac-vagal baroreflex sensitivity (BRS), improves oxygen saturation, lowers blood pressure, and reduces anxiety. Within the yoga tradition slow breathing is often paired with a contraction of the glottis muscles. This resistance breath “ujjayi” is performed at various rates and ratios of inspiration/expiration. To test whether ujjayi had additional positive effects to slow breathing, we compared BRS and ventilatory control under different breathing patterns (equal/unequal inspiration/expiration at 6 breath/min, with/without ujjayi), in 17 yoga-naive young healthy participants. BRS increased with slow breathing techniques with or without expiratory ujjayi (P < 0.05 or higher) except with inspiratory + expiratory ujjayi. The maximal increase in BRS and decrease in blood pressure were found in slow breathing with equal inspiration and expiration. This corresponded with a significant improvement in oxygen saturation without increase in heart rate and ventilation. Ujjayi showed similar increase in oxygen saturation but slightly lesser improvement in baroreflex sensitivity with no change in blood pressure. The slow breathing with equal inspiration and expiration seems the best technique for improving baroreflex sensitivity in yoga-naive subjects. The effects of ujjayi seems dependent on increased intrathoracic pressure that requires greater effort than normal slow breathing. PMID:23710236

  12. Sleep disordered breathing in pregnancy

    PubMed Central

    2015-01-01

    Key points Sleep disordered breathing (SDB) is common and the severity increases as pregnancy progresses. Frequent snoring, older age and high pre-pregnancy body mass index (>25 kg⋅m−2) could be reliable indicators for SDB in early pregnancy. SDB screening tools, including questionnaires, used in the nonpregnant population have poor predictive ability in pregnancy. Accumulating evidence suggests that SDB during pregnancy may be associated with increased risk of adverse pregnancy outcomes, including gestational diabetes and pre-eclampsia. However, the results should be interpreted cautiously because several studies failed to adjust for potential maternal confounders and have other study limitations. There are no pregnancy-specific practice guidelines for SDB treatment. Many clinicians and practices follow recommendations for the treatment in the general population. Women with pre-existing SDB might need to be reassessed, particularly after the sixth month of pregnancy, because symptoms can worsen with nasal congestion and weight gain. Educational aims To highlight the prevalence and severity of sleep disordered breathing (SDB) in the pregnant population. To inform readers about risk factors for SDB in pregnancy. To explore the impact of SDB on adverse maternal and fetal outcomes, and biological pathways for associated adverse maternal and fetal outcomes. To introduce current management options for SDB in pregnancy, including medical and behavioural approaches. Sleep disordered breathing (SDB) is very common during pregnancy, and is most likely explained by hormonal, physiological and physical changes. Maternal obesity, one of the major risk factors for SDB, together with physiological changes in pregnancy may predispose women to develop SDB. SDB has been associated with poor maternal and fetal outcomes. Thus, early identification, diagnosis and treatment of SDB are important in pregnancy. This article reviews the pregnancy-related changes affecting the

  13. Calculating rhythmicity of infant breathing using wavelets

    NASA Astrophysics Data System (ADS)

    Macey, Katherine E.; Page, Wyatt H.; Harper, Ronald M.; Macey, Paul M.; Ford, Rodney P. K.

    2000-12-01

    Breathing signals are one set of physiological data that may provide information regarding the mechanisms that cause SIDS. Isolated breathing pauses have been implicated in fatal events. Other features of interest include slow amplitude modulation of the breathing signal, a phenomenon whose origin is unclear, and periodic breathing. The latter describes a repetitive series of apnea, and may be considered an extreme manifestation of amplitude modulation with successive cessations of breathing. Rhythmicity is defined to assess the impact of amplitude modulation on breathing signals and describes the extent to which frequency components remain constant for the duration of the signal. The wavelet transform was used to identify sections of constant frequency components within signals. Rhythmicity can be evaluated for all the frequency components in a signal, for individual frequencies. The rhythmicity of eight breathing epochs from sleeping infants at high and low risk for SIDS was calculated. Initial results show breathing from infants at high risk for SIDS exhibits greater rhythmicity of modulating frequencies than breathing from low risk infants.

  14. The chemical neuroanatomy of breathing

    PubMed Central

    Alheid, George F.; McCrimmon, Donald R.

    2008-01-01

    The chemical neuroanatomy of breathing must ultimately encompass all the various neuronal elements physiologically identified in brainstem respiratory circuits and their apparent aggregation into “compartments” within the medulla and pons. These functionally defined respiratory compartments in the brainstem provide the major source of input to cranial motoneurons controlling the airways, and to spinal motoneurons activating inspiratory and expiratory pump muscles. This review provides an overview of the neuroanatomy of the major compartments comprising brainstem respiratory circuits, and a synopsis of the transmitters used by their constituent respiratory neurons. PMID:18706532

  15. 42 CFR 84.72 - Breathing tubes; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing tubes; minimum requirements. 84.72...-Contained Breathing Apparatus § 84.72 Breathing tubes; minimum requirements. Flexible breathing tubes used in conjunction with breathing apparatus shall be designed and constructed to prevent: (a)...

  16. 42 CFR 84.85 - Breathing bags; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing bags; minimum requirements. 84.85 Section...-Contained Breathing Apparatus § 84.85 Breathing bags; minimum requirements. (a) Breathing bags shall have.... (b) Breathing bags shall be constructed of materials which are flexible and resistant to...

  17. Breathing

    MedlinePlus Videos and Cool Tools

    ... size of the thoracic cavity and decreases the pressure inside. As a result, air rushes in and ... volume of the thoracic cavity decreases, while the pressure within it increases. As a result, the lungs ...

  18. Breathing

    MedlinePlus Videos and Cool Tools

    ... respiratory system conduct air to the lungs, such as the trachea (windpipe) which branches into smaller structures ... the thoracic cavity and decreases the pressure inside. As a result, air rushes in and fills the ...

  19. 42 CFR 84.81 - Compressed breathing gas and liquefied breathing gas containers; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from American National Standards... APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Self-Contained Breathing Apparatus § 84.81 Compressed breathing... the container. (d) Compressed breathing gas contained valves or a separate charging system or...

  20. 42 CFR 84.81 - Compressed breathing gas and liquefied breathing gas containers; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from American National Standards... APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Self-Contained Breathing Apparatus § 84.81 Compressed breathing... the container. (d) Compressed breathing gas contained valves or a separate charging system or...

  1. 42 CFR 84.81 - Compressed breathing gas and liquefied breathing gas containers; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from American National Standards... APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Self-Contained Breathing Apparatus § 84.81 Compressed breathing... the container. (d) Compressed breathing gas contained valves or a separate charging system or...

  2. 42 CFR 84.81 - Compressed breathing gas and liquefied breathing gas containers; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from American National Standards... APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Self-Contained Breathing Apparatus § 84.81 Compressed breathing... the container. (d) Compressed breathing gas contained valves or a separate charging system or...

  3. Lung function measurement with multiple-breath-helium washout system.

    PubMed

    Wang, J-Y; Suddards, M E; Mellor, C J; Owers-Bradley, J R

    2013-04-01

    Multiple-breath-washout (MBW) measurements are regarded as a sensitive technique which can reflect the ventilation inhomogeneity of respiratory airways. Typically nitrogen is used as the tracer gas and is washed out by pure oxygen in multiple-breath-nitrogen washout (MBNW) tests. In this study, instead of using nitrogen, (4)He is used as the tracer gas with smaller gas density which may be able to reach deeper into our lungs in a given time and the helium washout results may be more sensitive to the ventilation inhomogeneity in small airways. A multiple-breath-helium-washout (MBHW) system developed for the lung function study is also presented. Quartz tuning forks with a resonance frequency of 32,768Hz have been used for detecting the change of the respiratory gas density. The resonance frequency of the quartz tuning fork decreases linearly with increasing density of the surrounding gas. Knowing the CO2 concentration from the infrared carbon dioxide detector, the helium concentration can be determined. Results from 14 volunteers (3 mild asthmatics, 4 tobacco smokers, 1 with asthma history, 1 with COPD history, 5 normal) have shown that mild asthmatics have higher ventilation inhomogeneity in either conducting or acinar airways (or both). A feature has been found in washout curve of single breaths from 4 tobacco smokers with different length of smoking history which may indicate the early stage of respiratory ventilation inhomogeneity in acinar airways. PMID:22835436

  4. Medical Diagnostic Breath Analysis by Cavity Ring Down Spectroscopy

    NASA Astrophysics Data System (ADS)

    Guss, Joseph S.; Metsälä, Markus; Halonen, Lauri

    2009-06-01

    Certain medical conditions give rise to the presence of chemicals in the bloodstream. These chemicals - known as biomarkers - may also be present in low concentrations in human breath. Cavity ring down spectroscopy possesses the requisite selectivity and sensitivity to detect such biomarkers in the congested spectrum of a breath sample. The ulcer-causing bacterium, Helicobacter pylori, is a prolific producer of the enzyme urease, which catalyses the breakdown of urea ((NH_2)_2CO) in the stomach as follows: (NH_2)_2CO + H_2O ⟶ CO_2 + 2NH_3 Currently, breath tests seeking altered carbon-isotope ratios in exhaled CO_2 after the ingestion of ^{13}C- or ^{14}C-labeled urea are used to diagnose H. pylori infection. We present recent results from an ongoing collaboration with Tampere Area University Hospital. The study involves 100 patients (both infected and uninfected) and concerns the possible correlation between the bacterial infection and breath ammonia. D. Y. Graham, P. D. Klein, D. J. Evans, Jr, D. G. Evans, L. C. Alpert, A. R. Opekun, T. W. Boutton, Lancet 1(8543), 1174-7 March 1987.

  5. Clinical utility of breath ammonia for evaluation of ammonia physiology in healthy and cirrhotic adults

    PubMed Central

    Spacek, Lisa A; Mudalel, Matthew; Tittel, Frank; Risby, Terence H; Solga, Steven F

    2016-01-01

    Blood ammonia is routinely used in clinical settings to assess systemic ammonia in hepatic encephalopathy and urea cycle disorders. Despite its drawbacks, blood measurement is often used as a comparator in breath studies because it is a standard clinical test. We sought to evaluate sources of measurement error and potential clinical utility of breath ammonia compared to blood ammonia. We measured breath ammonia in real time by quartz enhanced photoacoustic spectrometry and blood ammonia in 10 healthy and 10 cirrhotic participants. Each participant contributed 5 breath samples and blood for ammonia measurement within 1 h. We calculated the coefficient of variation (CV) for 5 breath ammonia values, reported medians of healthy and cirrhotic participants, and used scatterplots to display breath and blood ammonia. For healthy participants, mean age was 22 years (±4), 70% were men, and body mass index (BMI) was 27 (±5). For cirrhotic participants, mean age was 61 years (±8), 60% were men, and BMI was 31 (±7). Median blood ammonia for healthy participants was within normal range, 10 μmol L−1 (interquartile range (IQR), 3–18) versus 46 μmol L−1 (IQR, 23–66) for cirrhotic participants. Median breath ammonia was 379 pmol mL−1 CO2 (IQR, 265–765) for healthy versus 350 pmol mL−1 CO2 (IQR, 180–1013) for cirrhotic participants. CV was 17 ± 6%. There remains an important unmet need in the evaluation of systemic ammonia, and breath measurement continues to demonstrate promise to fulfill this need. Given the many differences between breath and blood ammonia measurement, we examined biological explanations for our findings in healthy and cirrhotic participants. We conclude that based upon these preliminary data breath may offer clinically important information this is not provided by blood ammonia. PMID:26658550

  6. Respiration-correlated treatment delivery using feedback-guided breath hold: A technical study

    SciTech Connect

    Nelson, Christopher; Starkschall, George; Balter, Peter; Fitzpatrick, Mathew J.; Antolak, John A.; Tolani, Naresh; Prado, Karl

    2005-01-01

    Respiratory motion causes movement of internal structures in the thorax and abdomen, making accurate delivery of radiation therapy to tumors in those areas a challenge. To reduce the uncertainties caused by this motion, we have developed feedback-guided breath hold (FGBH), a novel delivery technique in which radiation is delivered only during a voluntary breath hold that is sustained for as long as the patient feels comfortable. Here we present the technical aspects of FGBH, which involve (1) fabricating the hardware so the respiratory trace can be displayed to the patient, (2) assembling a delay box to be used as a breath-hold detector, and (3) performing quality control tests to ensure that FGBH can be delivered accurately and safely. A commercial respiratory tracking system that uses an external fiducial to monitor abdominal wall motion generates and displays the breathing trace and specific positions in the breathing cycle where a breath hold needs to occur. Hardware was developed to present this display to the patient in the treatment position. Patients view the presentation either on a liquid crystal display or through a pair of virtual reality goggles. Using the respiratory trace as a visual aid, the patient performs a breath hold so that the position representing the location of a fiducial is held within a specified gating window. A delay box was fabricated to differentiate between gating signals received during free breathing and those received during breath hold, allowing radiation delivery only when the fiducial was within the breath-hold gating window. A quality control analysis of the gating delay box and the integrated system was performed to ensure that all of the hardware and components were ready for clinical use.

  7. Protective supplied breathing air garment

    DOEpatents

    Childers, Edward L.; von Hortenau, Erik F.

    1984-07-10

    A breathing air garment for isolating a wearer from hostile environments containing toxins or irritants includes a suit and a separate head protective enclosure or hood engaging a suit collar in sealing attachment. The hood and suit collar are cylindrically shaped and dimensioned to enable the wearer to withdraw his hands from the suit sleeves to perform manual tasks within the hood interior. Breathing air is supplied from an external air line with an air delivery hose attached to the hood interior. The hose feeds air into an annular halo-like fiber-filled plenum having spaced discharge orifices attached to the hood top wall. A plurality of air exhaust/check valves located at the suit extremities cooperate with the hood air delivery system to provide a cooling flow of circulating air from the hood throughout the suit interior. A suit entry seal provided on the suit rear torso panel permits access into the suit and is sealed with an adhesive sealing flap.

  8. [Stahl, Leibniz, Hoffmann and breathing].

    PubMed

    Carvallo, Sarah

    2006-01-01

    At the beginning of the XVIII th century, Wilhelm Gottfried Leibniz and Friedrich Hoffmann criticize Georg Ernst Stahl's medical theory. They differenciate between unsound and true reasonings. Namely, they validate Stahl's definition of breath but extracting it from its animist basis and placing it in an epistemology obeying to the principle of sufficient reason and to the mechanical model. The stahlian discovery consists in understanding breath as a calorific ventilation against the ancient conception; the iatromechanists recognize its accuracy, but they try then to transpose it to a mechanical model of ventilation. Using it in a different epistemological context implies that they analyze the idea of discovery "true" in its contents, but "wrong" in its hypothesis. It impels to examine the epistemology of medical knowledge, as science and therapeutics, and in its links with the other scientific theories. Thus, if Leibniz as philosopher and Hoffmann as doctor consider Stahl's animism so important, it is because its discoveries question the fundamental principles of medicine. PMID:17153053

  9. Protective supplied breathing air garment

    DOEpatents

    Childers, E.L.; Hortenau, E.F. von.

    1984-07-10

    A breathing air garment is disclosed for isolating a wearer from hostile environments containing toxins or irritants includes a suit and a separate head protective enclosure or hood engaging a suit collar in sealing attachment. The hood and suit collar are cylindrically shaped and dimensioned to enable the wearer to withdraw his hands from the suit sleeves to perform manual tasks within the hood interior. Breathing air is supplied from an external air line with an air delivery hose attached to the hood interior. The hose feeds air into an annular halo-like fiber-filled plenum having spaced discharge orifices attached to the hood top wall. A plurality of air exhaust/check valves located at the suit extremities cooperate with the hood air delivery system to provide a cooling flow of circulating air from the hood throughout the suit interior. A suit entry seal provided on the suit rear torso panel permits access into the suit and is sealed with an adhesive sealing flap. 17 figs.

  10. Submarines, spacecraft and exhaled breath.

    PubMed

    Pleil, Joachim D; Hansel, Armin

    2012-03-01

    Foreword The International Association of Breath Research (IABR) meetings are an eclectic gathering of researchers in the medical, environmental and instrumentation fields; our focus is on human health as assessed by the measurement and interpretation of trace chemicals in human exhaled breath. What may have escaped our notice is a complementary field of research that explores the creation and maintenance of artificial atmospheres practised by the submarine air monitoring and air purification (SAMAP) community. SAMAP is comprised of manufacturers, researchers and medical professionals dealing with the engineering and instrumentation to support human life in submarines and spacecraft (including shuttlecraft and manned rockets, high-altitude aircraft, and the International Space Station (ISS)). Here, the immediate concerns are short-term survival and long-term health in fairly confined environments where one cannot simply 'open the window' for fresh air. As such, one of the main concerns is air monitoring and the main sources of contamination are CO(2) and other constituents of human exhaled breath. Since the inaugural meeting in 1994 in Adelaide, Australia, SAMAP meetings have been held every two or three years alternating between the North American and European continents. The meetings are organized by Dr Wally Mazurek (a member of IABR) of the Defense Systems Technology Organization (DSTO) of Australia, and individual meetings are co-hosted by the navies of the countries in which they are held. An overriding focus at SAMAP is life support (oxygen availability and carbon dioxide removal). Certainly, other air constituents are also important; for example, the closed environment of a submarine or the ISS can build up contaminants from consumer products, cooking, refrigeration, accidental fires, propulsion and atmosphere maintenance. However, the most immediate concern is sustaining human metabolism: removing exhaled CO(2) and replacing metabolized O(2). Another

  11. Apolo Ohno: Breathing Easier | NIH MedlinePlus the Magazine

    MedlinePlus

    ... of this page please turn Javascript on. Feature: Breathing Easier Apolo Ohno: Breathing Easier Past Issues / Fall 2013 Table of Contents ... training, I started experiencing decreased exercise endurance, trouble breathing, and coughing. These symptoms affected my ability to ...

  12. How Does a Hopping Kangaroo Breathe?

    ERIC Educational Resources Information Center

    Giuliodori, Mauricio J.; Lujan, Heidi L.; Janbaih, Hussein; DiCarlo, Stephen E.

    2010-01-01

    We developed a model to demonstrate how a hopping kangaroo breathes. Interestingly, a kangaroo uses less energy to breathe while hopping than while standing still. This occurs, in part, because rather than using muscle power to move air into and out of the lungs, air is pulled into (inspiration) and pushed out of (expiration) the lungs as the…

  13. Tracheomalacia and breath holding: a case report.

    PubMed

    Griffiths, H; Doull, I; Williams, R G; Marnane, C

    2000-10-01

    A child with a long standing history of cyanotic breath holding attacks presented with acute respiratory distress. Subsequent investigation established that her clinical condition was caused by tracheomalacia. We hypothesise that tracheomalacia might be an under recognised contributor to cyanotic breath holding attacks, the pathogenesis of which is poorly understood. PMID:10999873

  14. EXHALED BREATH ANALYSIS FOR HUMAN EXPOSURE RESEARCH

    EPA Science Inventory

    Exhaled breath collection and analysis has historically been used in environmental research studies to characterize exposures to volatile organic compounds. The use of this approach is based on the fact that many compounds present in blood are reflected in the breath, and that...

  15. Sigh-induced changes of breathing pattern in preterm infants

    PubMed Central

    Jost, Kerstin; Latzin, Philipp; Fouzas, Sotirios; Proietti, Elena; Delgado-Eckert, Edgar W; Frey, Urs; Schulzke, Sven M

    2015-01-01

    Sighs are thought to play an important role in control of breathing. It is unclear how sighs are triggered, and whether preterm birth and lung disease influence breathing pattern prior to and after a sigh in infants. To assess whether frequency, morphology, size, and short-term variability in tidal volume (VT) before, during, and after a sigh are influenced by gestational age at birth and lung disease (bronchopulmonary dysplasia, BPD) in former preterm infants and healthy term controls measured at equivalent postconceptional age (PCA). We performed tidal breathing measurements in 143 infants during quiet natural sleep at a mean (SD) PCA of 44.8 (1.3) weeks. A total of 233 sighs were analyzed using multilevel, multivariable regression. Sigh frequency in preterm infants increased with the degree of prematurity and severity of BPD, but was not different from that of term controls when normalized to respiratory rate. After a sigh, VT decreased remarkably in all infants (paired t-test: P < 0.001). There was no major effect of prematurity or BPD on various indices of sigh morphology and changes in VT prior to or after a sigh. Short-term variability in VT modestly increased with maturity at birth and infants with BPD showed an earlier return to baseline variability in VT following a sigh. In early infancy, sigh-induced changes in breathing pattern are moderately influenced by prematurity and BPD in preterm infants. The major determinants of sigh-related breathing pattern in these infants remain to be investigated, ideally using a longitudinal study design. PMID:26564066

  16. Slow breathing influences cardiac autonomic responses to postural maneuver: Slow breathing and HRV.

    PubMed

    Vidigal, Giovanna Ana de Paula; Tavares, Bruna S; Garner, David M; Porto, Andrey A; Carlos de Abreu, Luiz; Ferreira, Celso; Valenti, Vitor E

    2016-05-01

    Chronic slow breathing has been reported to improve Heart Rate Variability (HRV) in patients with cardiovascular disorders. However, it is not clear regarding its acute effects on HRV responses on autonomic analysis. We evaluated the acute effects of slow breathing on cardiac autonomic responses to postural change manoeuvre (PCM). The study was conducted on 21 healthy male students aged between 18 and 35 years old. In the control protocol, the volunteer remained at rest seated for 15 min under spontaneous breathing and quickly stood up within 3 s and remained standing for 15 min. In the slow breathing protocol, the volunteer remained at rest seated for 10 min under spontaneous breath, then performed slow breathing for 5 min and rapidly stood up within 3 s and remained standing for 15 min. Slow breathing intensified cardiac autonomic responses to postural maneuver. PMID:27157952

  17. Computer simulation of breathing systems for divers

    SciTech Connect

    Sexton, P.G.; Nuckols, M.L.

    1983-02-01

    A powerful new tool for the analysis and design of underwater breathing gas systems is being developed. A versatile computer simulator is described which makes possible the modular ''construction'' of any conceivable breathing gas system from computer memory-resident components. The analysis of a typical breathing gas system is demonstrated using this simulation technique, and the effects of system modifications on performance of the breathing system are shown. This modeling technique will ultimately serve as the foundation for a proposed breathing system simulator under development by the Navy. The marriage of this computer modeling technique with an interactive graphics system will provide the designer with an efficient, cost-effective tool for the development of new and improved diving systems.

  18. Treatment of Chronic Breath-Holding in an Adult with Severe Mental Retardation: A Clinical Case Study

    ERIC Educational Resources Information Center

    Reed, Derek D.; Martens, Brian K.

    2008-01-01

    We describe a clinical case study surrounding the behavioral assessment and operant treatment of, an adult with severe mental retardation who engaged in chronic breath-holding. In this clinical case, previous neurological and medical testing had ruled out biological bases for the individual's breath-holding. A functional behavioral assessment…

  19. Breathing synchronization in interconnected networks

    PubMed Central

    Louzada, V. H. P.; Araújo, N. A. M.; Andrade, J. S.; Herrmann, H. J.

    2013-01-01

    Global synchronization in a complex network of oscillators emerges from the interplay between its topology and the dynamics of the pairwise interactions among its numerous components. When oscillators are spatially separated, however, a time delay appears in the interaction which might obstruct synchronization. Here we study the synchronization properties of interconnected networks of oscillators with a time delay between networks and analyze the dynamics as a function of the couplings and communication lag. We discover a new breathing synchronization regime, where two groups appear in each network synchronized at different frequencies. Each group has a counterpart in the opposite network, one group is in phase and the other in anti-phase with their counterpart. For strong couplings, instead, networks are internally synchronized but a phase shift between them might occur. The implications of our findings on several socio-technical and biological systems are discussed. PMID:24256765

  20. The indoor air we breathe.

    PubMed

    Oliver, L C; Shackleton, B W

    1998-01-01

    Increasingly recognized as a potential public health problem since the outbreak of Legionnaire's disease in Philadelphia in 1976, polluted indoor air has been associated with health problems that include asthma, sick building syndrome, multiple chemical sensitivity, and hypersensitivity pneumonitis. Symptoms are often nonspecific and include headache, eye and throat irritation, chest tightness and shortness of breath, and fatigue. Air-borne contaminants include commonly used chemicals, vehicular exhaust, microbial organisms, fibrous glass particles, and dust. Identified causes include defective building design and construction, aging of buildings and their ventilation systems, poor climate control, inattention to building maintenance. A major contributory factor is the explosion in the use of chemicals in building construction and furnishing materials over the past four decades. Organizational issues and psychological variables often contribute to the problem and hinder its resolution. This article describes the health problems related to poor indoor air quality and offers solutions. PMID:9769764

  1. Breath acetone monitoring by portable Si:WO3 gas sensors

    PubMed Central

    Righettoni, Marco; Tricoli, Antonio; Gass, Samuel; Schmid, Alex; Amann, Anton; Pratsinis, Sotiris E.

    2013-01-01

    Breath analysis has the potential for early stage detection and monitoring of illnesses to drastically reduce the corresponding medical diagnostic costs and improve the quality of life of patients suffering from chronic illnesses. In particular, the detection of acetone in the human breath is promising for non-invasive diagnosis and painless monitoring of diabetes (no finger pricking). Here, a portable acetone sensor consisting of flame-deposited and in situ annealed, Si-doped epsilon-WO3 nanostructured films was developed. The chamber volume was miniaturized while reaction-limited and transport-limited gas flow rates were identified and sensing temperatures were optimized resulting in a low detection limit of acetone (~20 ppb) with short response (10–15 s) and recovery times (35–70 s). Furthermore, the sensor signal (response) was robust against variations of the exhaled breath flow rate facilitating application of these sensors at realistic relative humidities (80–90%) as in the human breath. The acetone content in the breath of test persons was monitored continuously and compared to that of state-of-the-art proton transfer reaction mass spectrometry (PTR-MS). Such portable devices can accurately track breath acetone concentration to become an alternative to more elaborate breath analysis techniques. PMID:22790702

  2. How does breathing frequency affect the performance of an N95 filtering facepiece respirator and a surgical mask against surrogates of viral particles?

    PubMed

    He, Xinjian; Reponen, Tiina; McKay, Roy; Grinshpun, Sergey A

    2014-01-01

    Breathing frequency (breaths/min) differs among individuals and levels of physical activity. Particles enter respirators through two principle penetration pathways: faceseal leakage and filter penetration. However, it is unknown how breathing frequency affects the overall performance of N95 filtering facepiece respirators (FFRs) and surgical masks (SMs) against viral particles, as well as other health-relevant submicrometer particles. A FFR and SM were tested on a breathing manikin at four mean inspiratory flows (MIFs) (15, 30, 55, and 85 L/min) and five breathing frequencies (10, 15, 20, 25, and 30 breaths/min). Filter penetration (Pfilter) and total inward leakage (TIL) were determined for the tested respiratory protection devices against sodium chloride (NaCl) aerosol particles in the size range of 20 to 500 nm. "Faceseal leakage-to-filter" (FLTF) penetration ratios were calculated. Both MIF and breathing frequency showed significant effects (p < 0.05) on Pfilter and TIL. Increasing breathing frequency increased TIL for the N95 FFR whereas no clear trends were observed for the SM. Increasing MIF increased Pfilter and decreased TIL resulting in decreasing FLTF ratio. Most of FLTF ratios were >1, suggesting that the faceseal leakage was the primary particle penetration pathway at various breathing frequencies. Breathing frequency is another factor (besides MIF) that can significantly affect the performance of N95 FFRs, with higher breathing frequencies increasing TIL. No consistent trend of increase or decrease of TIL with either MIF or breathing frequency was observed for the tested SM. To potentially extend these findings beyond the manikin/breathing system used, future studies are needed to fully understand the mechanism causing the breathing frequency effect on the performance of respiratory protection devices on human subjects. PMID:24521067

  3. Measurement of low breath-alcohol concentrations: laboratory studies and field experience.

    PubMed

    Dubowski, K M; Essary, N A

    1999-10-01

    Recent federal rules and traffic law changes impose breath-alcohol thresholds of 0.02 and 0.04 g/210 L upon some classes of motor vehicle operators, such as juveniles and commercial vehicle operators. In federally regulated alcohol testing in the workplace, removal of covered workers from safety-sensitive duties, and other adverse actions, also occur at breath-alcohol concentrations (BrACs) of 0.02 and 0.04 g/210 L. We therefore studied performance of vapor-alcohol and breath-alcohol measurement at low alcohol concentrations in the laboratory and in the field, with current-generation evidential analyzers. We report here chiefly our field experience with evidential breath-alcohol testing of drinking drivers on paired breath samples using 62 Intoxilyzer 5000-D analyzers, for BrACs of 0-0.059 g/210 L. The data from 62 law enforcement breath-alcohol testing sites were collected and pooled, with BrACs recorded to three decimal places, and otherwise carried out under the standard Oklahoma evidential breath-alcohol testing protocol. For 2105 pooled simulator control tests at 0.06-0.13 g/210 L the mean +/- SD of the differences between target and result were -0.001 +/- 0.0035 g/210 L and 0.003 +/- 0.0023 g/210 L for signed and absolute differences, respectively (spans -0.016-0.010, 0.000-0.016). For 2078 paired duplicate breath-alcohol measurements with the Intoxilyzer 5000-D, the mean +/- SD difference (BrAC1-BrAC2) were 0.002 +/- 0.0026 (span 0-0.020 g/210 L). Variability of breath-alcohol measurements was related inversely to the alcohol concentration. Ninety-nine percent prediction limits for paired BrAC measurements correspond to a 0.020 g/210 L maximum absolute difference, meeting the NSC/CAOD recommendation that paired breath-alcohol analysis results within 0.02 g/210 L shall be deemed to be in acceptable agreement. We conclude that the field system for breath-alcohol analysis studied by us can and does perform reliably and accurately at low BrACs. PMID:10517542

  4. Breath Hydrogen as a Biomarker for Glucose Malabsorption after Roux-en-Y Gastric Bypass Surgery

    PubMed Central

    Andalib, Iman; Shah, Hiral; Bal, Bikram S.; Shope, Timothy R.; Finelli, Frederick C.; Koch, Timothy R.

    2015-01-01

    Objective. Abdominal symptoms are common after bariatric surgery, and these individuals commonly have upper gut bacterial overgrowth, a known cause of malabsorption. Breath hydrogen determination after oral glucose is a safe and inexpensive test for malabsorption. This study is designed to investigate breath hydrogen levels after oral glucose in symptomatic individuals who had undergone Roux-en-Y gastric bypass surgery. Methods. This is a retrospective study of individuals (n = 63; 60 females; 3 males; mean age 49 years) who had gastric bypass surgery and then glucose breath testing to evaluate abdominal symptoms. Results. Among 63 postoperative individuals, 51 (81%) had a late rise (≥45 minutes) in breath hydrogen or methane, supporting glucose malabsorption; 46 (90%) of these 51 subjects also had an early rise (≤30 minutes) in breath hydrogen or methane supporting upper gut bacterial overgrowth. Glucose malabsorption was more frequent in subjects with upper gut bacterial overgrowth compared to subjects with no evidence for bacterial overgrowth (P < 0.001). Conclusion. These data support the presence of intestinal glucose malabsorption associated with upper gut bacterial overgrowth in individuals with abdominal symptoms after gastric bypass surgery. Breath hydrogen testing after oral glucose should be considered to evaluate potential malabsorption in symptomatic, postoperative individuals. PMID:26538792

  5. Active breathing control (ABC): Determination and reduction of breathing-induced organ motion in the chest

    SciTech Connect

    Gagel, Bernd . E-mail: BGagel@UKAachen.de; Demirel, Cengiz M.P.; Kientopf, Aline; Pinkawa, Michael; Piroth, Marc; Stanzel, Sven; Breuer, Christian; Asadpour, Branka; Jansen, Thomas; Holy, Richard; Wildberger, Joachim E.; Eble, Michael J.

    2007-03-01

    Purpose: Extensive radiotherapy volumes for tumors of the chest are partly caused by interfractional organ motion. We evaluated the feasibility of respiratory observation tools using the active breathing control (ABC) system and the effect on breathing cycle regularity and reproducibility. Methods and Materials: Thirty-six patients with unresectable tumors of the chest were selected for evaluation of the ABC system. Computed tomography scans were performed at various respiratory phases starting at the same couch position without patient movement. Threshold levels were set at minimum and maximum volume during normal breathing cycles and at a volume defined as shallow breathing, reflecting the subjective maximal tolerable reduction of breath volume. To evaluate the extent of organ movement, 13 landmarks were considering using commercial software for image coregistration. In 4 patients, second examinations were performed during therapy. Results: Investigating the differences in a normal breathing cycle versus shallow breathing, a statistically significant reduction of respiratory motion in the upper, middle, and lower regions of the chest could be detected, representing potential movement reduction achieved through reduced breath volume. Evaluating interfraction reproducibility, the mean displacement ranged between 0.24 mm (chest wall/tracheal bifurcation) to 3.5 mm (diaphragm) for expiration and shallow breathing and 0.24 mm (chest wall) to 5.25 mm (diaphragm) for normal inspiration. Conclusions: By modifying regularity of the respiratory cycle through reduction of breath volume, a significant and reproducible reduction of chest and diaphragm motion is possible, enabling reduction of treatment planning margins.

  6. Breath analysis: translation into clinical practice.

    PubMed

    Brodrick, Emma; Davies, Antony; Neill, Paul; Hanna, Louise; Williams, E Mark

    2015-06-01

    Breath analysis in respiratory disease is a non-invasive technique which has the potential to complement or replace current screening and diagnostic techniques without inconvenience or harm to the patient. Recent advances in ion mobility spectrometry (IMS) have allowed exhaled breath to be analysed rapidly, reliably and robustly thereby facilitating larger studies of exhaled breath profiles in clinical environments. Preliminary studies have demonstrated that volatile organic compound (VOC) breath profiles of people with respiratory disease can be distinguished from healthy control groups but there is a need to validate, standardise and ensure comparability between laboratories before real-time breath analysis becomes a clinical reality. It is also important that breath sampling procedures and methodologies are developed in conjunction with clinicians and the practicalities of working within the clinical setting are considered to allow the full diagnostic potential of these techniques to be realised. A protocol is presented, which has been developed over three years and successfully deployed for quickly and accurately collecting breath samples from 323 respiratory patients recruited from 10 different secondary health care clinics. PMID:25971863

  7. An Ultrasonic Contactless Sensor for Breathing Monitoring

    PubMed Central

    Arlotto, Philippe; Grimaldi, Michel; Naeck, Roomila; Ginoux, Jean-Marc

    2014-01-01

    The monitoring of human breathing activity during a long period has multiple fundamental applications in medicine. In breathing sleep disorders such as apnea, the diagnosis is based on events during which the person stops breathing for several periods during sleep. In polysomnography, the standard for sleep disordered breathing analysis, chest movement and airflow are used to monitor the respiratory activity. However, this method has serious drawbacks. Indeed, as the subject should sleep overnight in a laboratory and because of sensors being in direct contact with him, artifacts modifying sleep quality are often observed. This work investigates an analysis of the viability of an ultrasonic device to quantify the breathing activity, without contact and without any perception by the subject. Based on a low power ultrasonic active source and transducer, the device measures the frequency shift produced by the velocity difference between the exhaled air flow and the ambient environment, i.e., the Doppler effect. After acquisition and digitization, a specific signal processing is applied to separate the effects of breath from those due to subject movements from the Doppler signal. The distance between the source and the sensor, about 50 cm, and the use of ultrasound frequency well above audible frequencies, 40 kHz, allow monitoring the breathing activity without any perception by the subject, and therefore without any modification of the sleep quality which is very important for sleep disorders diagnostic applications. This work is patented (patent pending 2013-7-31 number FR.13/57569). PMID:25140632

  8. Delayed feedback applied to breathing in humans

    NASA Astrophysics Data System (ADS)

    Janson, N. B.; Pototsky, A.; Parkes, C.

    2013-10-01

    We studied the response of healthy volunteers to the delayed feedback generated from the breathing signals. Namely, in the freely-breathing volunteers the breathing signal was recorded, delayed by τ seconds and fed back to the same volunteer in real time in the form of a visual and auditory stimulus of low intensity, i.e. the stimulus was crucially non-intrusive. In each case volunteers were instructed to breathe in the way which was most comfortable for them, and no explanation about the kind of applied stimulus was provided to them. Each volunteer experienced 10 different delay times ranging between 10% and 100% of the average breathing period without external stimulus. It was observed that in a significant proportion of subjects (11 out of 24) breathing was slowed down in the presence of delayed feedback with moderate delay. Also, in 6 objects out of 24 the delayed feedback was able to induce transition from nearly periodic to irregular breathing. These observations are consistent with the phenomena observed in numerical simulation of the models of periodic and chaotic self-oscillations with delays, and also in experiments with simpler self-oscillating systems.

  9. An ultrasonic contactless sensor for breathing monitoring.

    PubMed

    Arlotto, Philippe; Grimaldi, Michel; Naeck, Roomila; Ginoux, Jean-Marc

    2014-01-01

    The monitoring of human breathing activity during a long period has multiple fundamental applications in medicine. In breathing sleep disorders such as apnea, the diagnosis is based on events during which the person stops breathing for several periods during sleep. In polysomnography, the standard for sleep disordered breathing analysis, chest movement and airflow are used to monitor the respiratory activity. However, this method has serious drawbacks. Indeed, as the subject should sleep overnight in a laboratory and because of sensors being in direct contact with him, artifacts modifying sleep quality are often observed. This work investigates an analysis of the viability of an ultrasonic device to quantify the breathing activity, without contact and without any perception by the subject. Based on a low power ultrasonic active source and transducer, the device measures the frequency shift produced by the velocity difference between the exhaled air flow and the ambient environment, i.e., the Doppler effect. After acquisition and digitization, a specific signal processing is applied to separate the effects of breath from those due to subject movements from the Doppler signal. The distance between the source and the sensor, about 50 cm, and the use of ultrasound frequency well above audible frequencies, 40 kHz, allow monitoring the breathing activity without any perception by the subject, and therefore without any modification of the sleep quality which is very important for sleep disorders diagnostic applications. This work is patented (patent pending 2013-7-31 number FR.13/57569). PMID:25140632

  10. Applications of breath gas analysis in medicine

    NASA Astrophysics Data System (ADS)

    Amann, Anton; Poupart, Guy; Telser, Stefan; Ledochowski, Maximilian; Schmid, Alex; Mechtcheriakov, Sergei

    2004-12-01

    Volatile organic compounds (VOCs) in exhaled breath gas provide valuable information about the subjects' physiological and pathophysiological condition. Proton-transfer-reaction mass spectrometry (PTR-MS) allows rapid and online measurements of these substances. We present results of three studies illustrating the potential of breath gas analysis by PTR-MS in various contexts: long-time online monitoring of VOCs in sleeping subjects suggests that VOC profiles are related to sleep stages. Analysis of VOC concentrations in the breath of carbohydrate malabsorbers emphasizes the role played by bacteria in the gut. Finally, we demonstrate the large intra- and intersubject concentration variability of VOCs by considering one particular mass.

  11. Uncertainty in the Results of Breath-Alcohol Analyses

    NASA Astrophysics Data System (ADS)

    Labianca, Dominick A.

    1999-04-01

    This article provides information that expands upon and clarifies certain points put forth by Robert Q. Thompson in his article, "The Thermodynamics of Drunk Driving" (J. Chem. Educ. 1997, 74, 532-536). I have reservations concerning the limited scope and basis of some of Thompson's conclusions, and offer information consistent with a broader perspective. The principal focus of Thompson's work is on the postabsorptive state of alcohol metabolism. He makes recommendations concerning the application of breath-alcohol analysis to motor vehicle operators arrested for driving under the influence (DUI) of alcohol, assuming they are postabsorptive. I question the validity of a uniform application of this assumption to all DUI arrestees. Arguments are presented to support the position that many DUI arrestees can be in the absorptive state. Under that condition, breath-alcohol analysis can be particularly discriminatory to test subjects, and I have provided data consistent with this conclusion.

  12. Improved fireman's compressed air breathing system pressure vessel development program

    NASA Technical Reports Server (NTRS)

    King, H. A.; Morris, E. E.

    1973-01-01

    Prototype high pressure glass filament-wound, aluminum-lined pressurant vessels suitable for use in a fireman's compressed air breathing system were designed, fabricated, and acceptance tested in order to demonstrate the feasibility of producing such high performance, lightweight units. The 4000 psi tanks have a 60 standard cubic foot (SCF) air capacity, and have a 6.5 inch diamter, 19 inch length, 415 inch volume, weigh 13 pounds when empty, and contain 33 percent more air than the current 45 SCF (2250 psi) steel units. The current steel 60 SCF (3000 psi) tanks weigh approximately twice as much as the prototype when empty, and are 2 inches, or 10 percent shorter. The prototype units also have non-rusting aluminum interiors, which removes the hazard of corrosion, the need for internal coatings, and the possibility of rust particles clogging the breathing system.

  13. Welfare support-equipment for character input with head tilting and breathing

    NASA Astrophysics Data System (ADS)

    Nakazawa, Nobuaki; Yamada, Kou; Matsui, Toshikazu; Itoh, Isao

    2005-12-01

    This paper describes support-equipment of operating a personal computer for users who have an obstacle on the regions of upper limb. The user wears a head set device with an angle sensor, and holds a plastic pipe connected to a pressure sensor in his or her mouth. Tilting his or her head and breathing are used for mouse cursor operation and characters input. Considering user's body conditions, the voluntary angle range of head tilting and strength of breathing are memorized to the controller beforehand, and obtained information is reflected for operations without fatigue. The character display board is used to indicate the Japanese characters and input options such as Back Space or Enter. Tilting motions change the indicated character and breathing actions can select and input the illuminated functions on the character display board. In test trial, it is confirmed that Japanese characters including Kanji and Katakana can be input with head tilting and breathing, instead of a general keyboard.

  14. Transient Suppression of Dbx1 PreBötzinger Interneurons Disrupts Breathing in Adult Mice.

    PubMed

    Vann, Nikolas C; Pham, Francis D; Hayes, John A; Kottick, Andrew; Del Negro, Christopher A

    2016-01-01

    Interneurons derived from Dbx1-expressing precursors located in the brainstem preBötzinger complex (preBötC) putatively form the core oscillator for inspiratory breathing movements. We tested this Dbx1 core hypothesis by expressing archaerhodopsin in Dbx1-derived interneurons and then transiently hyperpolarizing these neurons while measuring respiratory rhythm in vitro or breathing in vagus-intact adult mice. Transient illumination of the preBötC interrupted inspiratory rhythm in both slice preparations and sedated mice. In awake mice, light application reduced breathing frequency and prolonged the inspiratory duration. Support for the Dbx1 core hypothesis previously came from embryonic and perinatal mouse experiments, but these data suggest that Dbx1-derived preBötC interneurons are rhythmogenic in adult mice too. The neural origins of breathing behavior can be attributed to a localized and genetically well-defined interneuron population. PMID:27611210

  15. A breath sampling system assessing the influence of respiratory rate on exhaled breath composition.

    PubMed

    Lomonaco, T; Salvo, P; Ghimenti, S; Biagini, D; Bellagambi, F; Fuoco, R; Di Francesco, F

    2015-08-01

    This work presents a computerized system to monitor mouth pressure, tidal volume, exhaled airflow, respiration rate and end-tidal partial pressure of CO2 during breath collection. The system was used to investigate the effect of different respiratory rates on the volatile organic compounds (VOCs) concentrations in exhaled breath. For this purpose, VOCs with well-defined biochemical pathways and different chemical and physical properties were selected as biomarkers related to metabolism (acetone and isopropyl alcohol), cholesterol synthesis (isoprene) and intestinal microflora activity (ethanol). Mixed breath was collected from a nominally healthy volunteer in resting conditions by filling a Nalophan bag. The subject followed a regimented breathing pattern at different respiratory rates (10, 30 and 50 breaths per minute). Results highlight that ventilation pattern strongly influences the concentration of the selected compounds. The proposed system allows exhaled breath to be collected also in patients showing dyspnea such as in case of chronic heart failure, asthma and pulmonary diseases. PMID:26738056

  16. Portable breathing apparatus for coal mines

    NASA Technical Reports Server (NTRS)

    Vandolah, R. W.

    1972-01-01

    The state of the art in portable oxygen breathing equipment is reported. Considered are self-containing as well as chemically generating oxygen sources and their effectiveness and limitations in mine rescue operations.

  17. Does a Smaller Waist Mean Smelly Breath?

    MedlinePlus

    ... overnight on the surface of the tongue when saliva production is diminished." ; Tips to combat halitosis: ; 1. Drink ... after meals can help keep bad breath away. Saliva production increases during chewing and this can help neutralize ...

  18. Shortness of Breath in Infants and Children

    MedlinePlus

    ... object? Yes Any small object can block an airway and cause shortness of breath or CHOKING. Take ... remove the object). If necessary, carefully clear the airway with a sweeping motion of your finger. If ...

  19. Breathing Problems - Multiple Languages: MedlinePlus

    MedlinePlus

    ... Supplements Videos & Tools You Are Here: Home → Multiple Languages → All Health Topics → Breathing Problems URL of this page: https://medlineplus.gov/languages/breathingproblems.html Other topics A-Z A B ...

  20. Breathing exercises for adults with asthma.

    PubMed

    2015-11-01

    Asthma is a common long-term condition that remains poorly controlled in many people despite the availability of pharmacological interventions, evidence-based treatment guidelines and care pathways.(1) There is considerable public interest in the use of non-pharmacological approaches for the treatment of asthma.(2) A survey of people with asthma reported that many have used complementary and alternative medicine, often without the knowledge of their clinical team.(3) Such interventions include breathing techniques, herbal products, homeopathy and acupuncture. The role of breathing exercises within the management of asthma has been controversial, partly because early claims of effectiveness were exaggerated.(4) UK national guidance and international guidelines on the management of asthma have included the option of breathing exercise programmes as an adjuvant to pharmacological treatment.(5,6) Here we discuss the types of breathing exercises used and review the evidence for their effectiveness. PMID:26563876

  1. Progress in the Development of Volatile Exhaled Breath Signatures of Lung Cancer

    PubMed Central

    Wang, Xiao-Feng; Lim, Sung; Jett, James; Choi, Humberto; Zhang, Qi; Beukemann, Mary; Seeley, Meredith; Martino, Ray; Rhodes, Paul

    2015-01-01

    Rationale: Volatile organic compounds present in the exhaled breath have shown promise as biomarkers of lung cancer. Advances in colorimetric sensor array technology, breath collection methods, and clinical phenotyping may lead to the development of a more accurate breath biomarker. Objectives: Perform a discovery-level assessment of the accuracy of a colorimetric sensor array–based volatile breath biomarker. Methods: Subjects with biopsy-confirmed untreated lung cancer, and others at risk for developing lung cancer, performed tidal breathing into a breath collection instrument designed to expose a colorimetric sensor array to the alveolar portion of the breath. Random forest models were built from the sensor output of 70% of the study subjects and were tested against the remaining 30%. Models were developed to separate cancer and subgroups from control, and to characterize the cancer. Additional models were developed after matching the clinical phenotypes of cancer and control subjects. Measurements and Main Results: Ninety-seven subjects with lung cancer and 182 control subjects participated. The accuracies, reported as C-statistics, for models of cancer and subgroups versus control ranged from 0.794 to 0.861. The accuracy was improved by developing models for cancer and control groups selected through propensity matching for clinical variables. A model built using only subjects from the largest available clinical subgroup (49 subjects) had a C-statistic of 0.982. Models developed and tested to characterize cancer histology, and to compare early- with late-stage cancer, had C-statistics of 0.881–0.960. Conclusions: The colorimetric sensor array signature of exhaled breath volatile organic compounds was capable of distinguishing patients with lung cancer from clinically relevant control subjects in a discovery level trial. The incorporation of clinical phenotypes into the further development of this biomarker may optimize its accuracy. PMID:25965541

  2. Breathing patterns during eccentric exercise.

    PubMed

    Lechauve, J B; Perrault, H; Aguilaniu, B; Isner-Horobeti, M E; Martin, V; Coudeyre, E; Richard, R

    2014-10-01

    Eccentric (ECC) work is interesting for rehabilitation purposes because it is more efficient than concentric (CON). This study assessed respiratory patterns and electromyographic activity (EMG) during ECC and CON cycling, both at similar power outputs and VO2 in eight healthy male subjects. Measurements include ventilation (VE), tidal volume (Vt), breathing frequency (Fb), arterial blood gases, and vastus lateralis (VL) and biceps brachii (BB) EMG. At the same mechanical power, VO2 and VE were fivefold lower in ECC as was VL EMG while BB EMG, Vd/Vt, PaO2 and PaCO2, were not different between modalities. At the same VO2, there was no difference in VE but Vt was lower and Fb higher in ECC. VL EMG was not different between modalities while BB EMG was higher in ECC. The latter observation suggests that ECC cycling may result in arm bracing and restricted chest expansion. Since hyperpnea is a known trigger of exaggerated dynamic hyperinflation, the prescription of ECC cycling for patient rehabilitation requires further assessment. PMID:25083913

  3. The retrotrapezoid nucleus and breathing.

    PubMed

    Guyenet, Patrice G; Stornetta, Ruth L; Abbott, Stephen B G; Depuy, Seth D; Kanbar, Roy

    2012-01-01

    The retrotrapezoid nucleus (RTN) is located in the rostral medulla oblongata close to the ventral surface and consists of a bilateral cluster of glutamatergic neurons that are non-aminergic and express homeodomain transcription factor Phox2b throughout life. These neurons respond vigorously to increases in local pCO(2) via cell-autonomous and paracrine (glial) mechanisms and receive additional chemosensory information from the carotid bodies. RTN neurons exclusively innervate the regions of the brainstem that contain the respiratory pattern generator (RPG). Lesion or inhibition of RTN neurons largely attenuates the respiratory chemoreflex of adult rats whereas their activation increases respiratory rate, inspiratory amplitude and active expiration. Phox2b mutations that cause congenital central hypoventilation syndrome in humans prevent the development of RTN neurons in mice. Selective deletion of the RTN Phox2b-VGLUT2 neurons by genetic means in mice eliminates the respiratory chemoreflex in neonates.In short, RTN Phox2b-VGLUT2 neurons are a major nodal point of the CNS network that regulates pCO(2) via breathing and these cells are probable central chemoreceptors. PMID:23080151

  4. Haemoptysis after breath-hold diving.

    PubMed

    Boussuges, A; Pinet, C; Thomas, P; Bergmann, E; Sainty, J M; Vervloet, D

    1999-03-01

    Pulmonary oedema has been described in swimmers and self-contained underwater breathing apparatus (Scuba) divers. This study reports three cases of haemoptysis secondary to alveolar haemorrhage in breath-hold divers. Contributory factors, such as haemodynamic modifications secondary to immersion, cold exposure, exercise and exposure to an increase in ambient pressure, could explain this type of accident. Furthermore, these divers had taken aspirin, which may have aggravated the bleeding. PMID:10232449

  5. Breathing hospital air can make you sick.

    PubMed

    Brownson, K

    1999-12-01

    Indoor air quality has deteriorated so much since the 1970s oil shortage and subsequent energy-efficient construction of buildings that people are becoming seriously ill by just breathing the indoor air. This is a problem with all industrial buildings and hospital staff are at particular risk. There are various things that hospital managers from different departments can do to make the air safe for staff and patients to breathe. PMID:10787631

  6. Monitoring breath markers under controlled conditions.

    PubMed

    Righettoni, Marco; Ragnoni, Alessandro; Güntner, Andreas T; Loccioni, Claudio; Pratsinis, Sotiris E; Risby, Terence H

    2015-12-01

    Breath analysis has the potential to detect and monitor diseases as well as to reduce the corresponding medical costs while improving the quality of a patient's life. Herein, a portable prototype, consisting of a commercial breath sampler modified to work as a platform for solid-state gas sensors was developed. The sensor is placed close to the mouth (<10 cm) and minimizes the mouth-to-sensor path to avoid contamination and dilution of the target breath marker. Additionally with an appropriate cooling concept, even high sensor operating temperatures (e.g. 350 °C) could be used. Controlled sampling is crucial for accurate repeatable analysis of the human breath and these concerns have been addressed by this novel prototype. The device helps a subject control their exhaled flow rate which increases reproducibility of intra-subject breath samples. The operation of this flame-made selective chemo-resistive gas sensor is demonstrated by the detection of breath acetone. PMID:26469378

  7. A free-breathing lung motion model

    NASA Astrophysics Data System (ADS)

    Zhao, Tianyu

    Lung cancer has been the leading cause of cancer deaths for decades in the United States. Although radiotherapy is one of the most effective treatments, side effects from error in delivery of radiation due to organ motion during breathing remain a significant issue. To compensate the breathing motion during the treatment, a free breathing lung motion model, x= x0+αv+betaf, was developed and discussed, where x is the position of a piece of tissue located at reference position x0. α is a parameter which characterizes the motion due to local air filling (motion as a function of tidal volume) and beta is the parameter that accounts for the motion due to the imbalance of dynamical stress distributions during inspiration and exhalation which cause lung motion hysteresis (motion as a function of airflow). The parameters α and beta together provide a quantitative characterization of breathing motion that inherently includes the complex hysteresis interplay. The theoretical foundation of the model was built by investigating the stress distribution inside of a lung and the biomechanical properties of the lung tissues. Accuracy of the model was investigated by using 49 free-breathing patient data sets. Applications of the model in localizing lung cancer, monitoring radiation damage and suppressing artifacts in free-breathing PET images were also discussed. This work supported in part by NIHR01CA096679 and NIHR01CA116712.

  8. Breath-based biomarkers for tuberculosis

    NASA Astrophysics Data System (ADS)

    Kolk, Arend H. J.; van Berkel, Joep J. B. N.; Claassens, Mareli M.; Walters, Elisabeth; Kuijper, Sjoukje; Dallinga, Jan W.; van Schooten, Fredrik-Jan

    2012-06-01

    We investigated the potential of breath analysis by gas chromatography - mass spectrometry (GC-MS) to discriminate between samples collected prospectively from patients with suspected tuberculosis (TB). Samples were obtained in a TB endemic setting in South Africa where 28% of the culture proven TB patients had a Ziehl-Neelsen (ZN) negative sputum smear. A training set of breath samples from 50 sputum culture proven TB patients and 50 culture negative non-TB patients was analyzed by GC-MS. A classification model with 7 compounds resulted in a training set with a sensitivity of 72%, specificity of 86% and accuracy of 79% compared with culture. The classification model was validated with an independent set of breath samples from 21 TB and 50 non-TB patients. A sensitivity of 62%, specificity of 84% and accuracy of 77% was found. We conclude that the 7 volatile organic compounds (VOCs) that discriminate breath samples from TB and non-TB patients in our study population are probably host-response related VOCs and are not derived from the VOCs secreted by M. tuberculosis. It is concluded that at present GC-MS breath analysis is able to differentiate between TB and non-TB breath samples even among patients with a negative ZN sputum smear but a positive culture for M. tuberculosis. Further research is required to improve the sensitivity and specificity before this method can be used in routine laboratories.

  9. Improved oxygen sources for breathing apparatus

    NASA Technical Reports Server (NTRS)

    Wood, P. C.; Wydeven, T.

    1983-01-01

    Research is described which is directed toward the preparation of chemical oxygen sources which exhibited improved O2 storage and reaction characteristics when compared to potassium superoxide (KO2). The initial focus of the research was the preparation of calcium superoxide (Ca(O2)2) by the disproportionation of calcium peroxide diperoxyhydrate. the Ca(O2)2 was characterized by chemical, thermal, and x ray analyses. Several methods for scaling up the Ca(O2)2 syntheis process were studied. The reactivity of Ca(O2)2 toward humidified carbon dioxide (CO2) was evaluated and was compared to that of KO2 under flow test conditions approximating those existing in portable breathing apparatus. The reactivities of mixtures of KO2 and Ca(O2)2 or lithium peroxide towards humidified CO2 were also studied. Finally, an analysis of two commercial, KO2-based, self contained self rescuers was conducted to determine the potential weight and volume savings which would be possible if Ca(O2)2 or a mixture of KO2 and Ca(O2)2 were used as a replacement for KO2.

  10. Transcutaneous carbon dioxide during sleep-disordered breathing.

    PubMed

    Rimpilä, Ville; Hosokawa, Keisuke; Huhtala, Heini; Saaresranta, Tarja; Salminen, Aaro V; Polo, Olli

    2015-12-01

    Respiratory drive is tightly controlled by the carbon dioxide levels. We tested the hypothesis that sequences of sleep apnoea (obstructive, central or mixed), hypopnoea and flow limitation are characterized by different levels of transcutaneous CO2 (PtcCO2). Polygraphic recordings (n=555) from patients with suspected sleep-disordered breathing (SDB) were retrospectively screened to find sequences (5 min or 10 events) of both SDB and steady breathing. Eighty-eight SDB sequences from 44 patients were included and PtcCO2 and SpO2 values were collected. PtcCO2 values during sequences were normalized by setting wakefulness level as 100%. In terms of PtcCO2, apnoea sequences with central component (central (n=7) and mixed (n=3) apnoea) did not differ from wakefulness (102.0% vs 100%, p=0.122) whereas obstructive apnoea (105.8%, p<0.001) and hypopnoea did (105.4%, p<0.001). PtcCO2 during flow limitation was higher than that during any other sequence, including steady breathing (112.2% vs 108.4%, p=0.022). Continuous PtcCO2 monitoring during sleep adds to the understanding of different SDB phenotypes. PMID:26474829

  11. Investigation of breathing parameters during odor perception and olfactory imagery.

    PubMed

    Kleemann, A M; Kopietz, R; Albrecht, J; Schöpf, V; Pollatos, O; Schreder, T; May, J; Linn, J; Brückmann, H; Wiesmann, M

    2009-01-01

    Compared with visual and auditory imagery, little is known about olfactory imagery. There is evidence that respiration may be altered by both olfactory perception and olfactory imagery. In order to investigate this relationship, breathing parameters (respiratory minute volume, respiratory amplitude, and breathing rate) in human subjects during olfactory perception and olfactory imagery were investigated. Fifty-six subjects having normal olfactory function were tested. Nasal respiration was measured using a respiratory pressure sensor. Using an experimental block design, we alternately presented odors or asked the subjects to imagine a given smell. Four different pleasant odors were used: banana, rose, coffee, and lemon odor. We detected a significant increase in respiratory minute volume between olfactory perception and the baseline condition as well as between olfactory imagery and baseline condition. Additionally we found significant differences in the respiratory amplitude between imagery and baseline condition and between odor and imagery condition. Differences in the breathing rate between olfactory perception, olfactory imagery, and baseline were not statistically significant. We conclude from our results that olfactory perception and olfactory imagery both have effects on the human respiratory profile and that these effects are based on a common underlying mechanism. PMID:18701432

  12. The effect of breathing an ambient low‐density, hyperoxic gas on the perceived effort of breathing and maximal performance of exercise in well‐trained athletes

    PubMed Central

    Ansley, L; Petersen, D; Thomas, A; Gibson, A St Clair; Robson‐Ansley, P; Noakes, T D

    2007-01-01

    Background The role of the perception of breathing effort in the regulation of performance of maximal exercise remains unclear. Aims To determine whether the perceived effort of ventilation is altered through substituting a less dense gas for normal ambient air and whether this substitution affects performance of maximal incremental exercise in trained athletes. Methods Eight highly trained cyclists (mean SD) maximal oxygen consumption (VO2max) = 69.9 (7.9) (mlO2/kg/min) performed two randomised maximal tests in a hyperbaric chamber breathing ambient air composed of either 35% O2/65% N2 (nitrox) or 35% O2/65% He (heliox). A ramp protocol was used in which power output was incremented at 0.5 W/s. The trials were separated by at least 48 h. The perceived effort of breathing was obtained via Borg Category Ratio Scales at 3‐min intervals and at fatigue. Oxygen consumption (VO2) and minute ventilation (VE) were monitored continuously. Results Breathing heliox did not change the sensation of dyspnoea: there were no differences between trials for the Borg scales at any time point. Exercise performance was not different between the nitrox and heliox trials (peak power output = 451 (58) and 453 (56) W), nor was VO2max (4.96 (0.61) and 4.88 (0.65) l/min) or maximal VE (157 (24) and 163 (22) l/min). Between‐trial variability in peak power output was less than either VO2max or maximal VE. Conclusion Breathing a less dense gas does not improve maximal performance of exercise or reduce the perception of breathing effort in highly trained athletes, although an attenuated submaximal tidal volume and VE with a concomitant reduction in VO2 suggests an improved gas exchange and reduced O2 cost of ventilation when breathing heliox. PMID:17062658

  13. Increased oxygen load in the prefrontal cortex from mouth breathing: a vector-based near-infrared spectroscopy study

    PubMed Central

    Sano, Sayaka; Oka, Noriyuki; Yoshino, Kayoko; Kato, Toshinori

    2013-01-01

    Individuals who habitually breathe through the mouth are more likely than nasal breathers to have sleep disorders and attention deficit hyperactive disorder. We hypothesized that brain hemodynamic responses in the prefrontal cortex might be different for mouth and nasal breathing. To test this hypothesis, we measured changes in oxyhemoglobin and deoxyhemoglobin in the prefrontal cortex during mouth breathing and nasal breathing in healthy adults (n=9) using vector-based near-infrared spectroscopy. The angle k, calculated from changes in oxyhemoglobin and deoxyhemoglobin and indicating the degree of oxygen exchange, was significantly higher during mouth breathing (P<0.05), indicating an increased oxygen load. Mouth breathing also caused a significant increase in deoxyhemoglobin, but oxyhemoglobin did not increase. This difference in oxygen load in the brain arising from different breathing routes can be evaluated quantitatively using vector-based near-infrared spectroscopy. Phase responses could help to provide an earlier and more reliable diagnosis of a patient’s habitual breathing route than a patient interview. PMID:24169579

  14. Detection of response to command using voluntary control of breathing in disorders of consciousness

    PubMed Central

    Charland-Verville, Vanessa; Lesenfants, Damien; Sela, Lee; Noirhomme, Quentin; Ziegler, Erik; Chatelle, Camille; Plotkin, Anton; Sobel, Noam; Laureys, Steven

    2014-01-01

    Background: Detecting signs of consciousness in patients in a vegetative state/unresponsive wakefulness syndrome (UWS/VS) or minimally conscious state (MCS) is known to be very challenging. Plotkin et al. (2010) recently showed the possibility of using a breathing-controlled communication device in patients with locked in syndrome. We here aim to test a breathing-based “sniff controller” that could be used as an alternative diagnostic tool to evaluate response to command in severely brain damaged patients with chronic disorders of consciousness (DOC). Methods: Twenty-five DOC patients were included. Patients’ resting breathing-amplitude was measured during a 5 min resting condition. Next, they were instructed to end the presentation of a music sequence by sniffing vigorously. An automated detection of changes in breathing amplitude (i.e., >1.5 SD of resting) ended the music and hence provided positive feedback to the patient. Results: None of the 11 UWS/VS patients showed a sniff-based response to command. One out of 14 patients with MCS was able to willfully modulate his breathing pattern to answer the command on 16/19 trials (accuracy 84%). Interestingly, this patient failed to show any other motor response to command. Discussion: We here illustrate the possible interest of using breathing-dependent response to command in the detection of residual cognition in patients with DOC after severe brain injury. PMID:25566035

  15. Breath Analysis Using a Time-of-Flight Camera and Pressure Belts.

    PubMed

    Zalud, Ludek; Kotova, Marketa; Kocmanová, Petra; Dobsak, Petr; Kolarova, Jana

    2016-06-01

    The proper way of breathing is important for everyone. Healthy people often do not follow respiration until breathing problems start-during stress or during sport activity in physiological cases. More serious cases are stroke, injury, or surgery of the chest and others. So, learning to breathe correctly and/or breathing diagnosis is considerable for many reasons. Two novel methods of breath analysis suitable for diagnostics and rehabilitation are presented. The first technique utilizes pressure belts fastened to the patient's belly and chest, and the second method relies on a SwissRanger SR-4000 time-of-flight camera. The measurement principles are described together with the advantages and disadvantages of the applied techniques. The SwissRanger camera depth calibration is proposed to facilitate better results during the breath analysis. The methods are tested on a group of students to provide a comparison of their individual performances. As it was demonstrated, presented methods proved to work reliably. The method based on time-of-flight camera seems to be more suitable for diagnosis, while the method based on pressure belts is more suitable for rehabilitation and biofeedback applications. PMID:26527126

  16. Hydrogen sulphide in exhaled breath: a potential biomarker for small intestinal bacterial overgrowth in IBS.

    PubMed

    Banik, Gourab Dutta; De, Anulekha; Som, Suman; Jana, Subhra; Daschakraborty, Sunil B; Chaudhuri, Sujit; Pradhan, Manik

    2016-06-01

    There is a pressing need to develop a novel early-detection strategy for the precise evolution of small intestinal bacterial overgrowth (SIBO) in irritable bowel syndrome (IBS) patients. The current method based on a hydrogen breath test (HBT) for the detection of SIBO is highly controversial. HBT has many limitations and drawbacks. It often fails to indentify SIBO when IBS individuals have 'non-hydrogen-producing' colonic bacteria. Here, we show that hydrogen sulphide (H2S) in exhaled breath is distinctly altered for diarrhea-predominant IBS individuals with positive and negative SIBO by the activity of intestinal sulphate-reducing bacteria. Subsequently, by analyzing the excretion kinetics of breath H2S, we found a missing link between breath H2S and SIBO when HBT often fails to diagnose SIBO. Moreover, breath H2S can track the precise evolution of SIBO, even after the eradication of bacterial overgrowth. Our findings suggest that the changes in H2S in the bacterial environment may contribute to the pathogenesis of SIBO and the breath H2S as a potential biomarker for non-invasive, rapid and precise assessment of SIBO without the endoscopy-based microbial culture of jejunal aspirates, and thus may open new perspectives into the pathophysiology of SIBO in IBS subjects. PMID:27163246

  17. A novel approach to detecting breathing-fatigue cracks based on dynamic characteristics

    NASA Astrophysics Data System (ADS)

    Yan, Guirong; De Stefano, Alessandro; Matta, Emiliano; Feng, Ruoqiang

    2013-01-01

    During the service life of structures, breathing-fatigue cracks may occur in structural members due to dynamic loadings acting on them. These fatigue cracks, if undetected, might lead to a catastrophic failure of the whole structural system. Although a number of approaches have been proposed to detect breathing-fatigue cracks, some of them appear rather sophisticated or expensive (requiring complicated equipment), and others suffer from a lack of sensitivity. In this study, a simple and efficient approach to detecting breathing-fatigue cracks is developed based on dynamic characteristics of breathing cracks. First, considering that breathing cracks introduce bilinearity into structures, a simple system identification method for bilinear systems is proposed by taking best advantage of dynamic characteristics of bilinear systems. This method transfers nonlinear system identification into linear system identification by dividing impulse or free-vibration responses into different parts corresponding to each stiffness region according to the stiffness interface. In this way, the natural frequency of each region can be identified using any modal identification approach applicable to linear systems. Second, the procedure for identifying the existence of breathing fatigue cracks and quantifying the cracks qualitatively is proposed by looking for the difference in the identified natural frequency between regions. Third, through introducing Hilbert transform, the proposed procedure is extended to identify fatigue cracks in piecewise-nonlinear systems. The proposed system identification method and crack detection procedure have been successfully validated by numerical simulations and experimental tests.

  18. Tracking performance with two breathing oxygen concentrations after high altitude rapid decompression

    NASA Technical Reports Server (NTRS)

    Nesthus, Thomas E.; Schiflett, Samuel G.; Oakley, Carolyn J.

    1992-01-01

    Current military aircraft Liquid Oxygen (LOX) systems supply 99.5 pct. gaseous Aviator's Breathing Oxygen (ABO) to aircrew. Newer Molecular Sieve Oxygen Generation Systems (MSOGS) supply breathing gas concentration of 93 to 95 pct. O2. The margin is compared of hypoxia protection afforded by ABO and MSOGS breathing gas after a 5 psi differential rapid decompression (RD) in a hypobaric research chamber. The barometric pressures equivalent to the altitudes of 46000, 52000, 56000, and 60000 ft were achieved from respective base altitudes in 1 to 1.5 s decompressions. During each exposure, subjects remained at the simulated peak altitude breathing either 100 or 94 pct. O2 with positive pressure for 60 s, followed by a rapid descent to 40000 ft. Subjects used the Tactical Life Support System (TLSS) for high altitude protection. Subcritical tracking task performance on the Performance Evaluation Device (PED) provided psychomotor test measures. Overall tracking task performance results showed no differences between the MSOGS breathing O2 concentration of 94 pct. and ABO. Significance RMS error differences were found between the ground level and base altitude trials compared to peak altitude trials. The high positive breathing pressures occurring at the peak altitudes explained the differences.

  19. Allergens involved in occupational asthma caused by baby's breath (Gypsophila paniculata).

    PubMed

    Schroeckenstein, D C; Meier-Davis, S; Yunginger, J W; Bush, R K

    1990-08-01

    Although the floral industry deals with many potential allergens, few examples of occupational asthma exist in this industry. A 22-year-old florist experienced symptoms of rhinitis, conjunctivitis, and asthma on exposure to baby's breath. To determine the contribution of baby's breath to the patient's symptoms, an extract of baby's breath was prepared. Prick skin tests with a 1:10(-5) wt/vol concentration of the extract produced an immediate response, whereas nonexposed atopic and normal control subjects did not react. The patient's asthmatic response to baby's breath was confirmed by bronchial challenge that caused an immediate fall in FEV1 of 26.2% from baseline after inhalation of 88 breath units of the extract. With a direct RAST, the patient's serum bound 38 times the amount of IgE bound by the negative control. IgE binding in the RAST was inhibited by the baby's breath extract but not by unrelated inhibitors (ragweed and tree pollens). Immunoblotting demonstrated IgE binding to 13 protein bands in the extract with molecular weights ranging from 11.5 to 68 kd. Serum from a patient previously reported to have sensitivity to baby's breath recognized five protein bands. Three proteins with molecular weights of 27, 31, and 37 kd were recognized by both patients' sera. We conclude that this patient developed IgE-mediated sensitivity to multiple allergens in baby's breath. This study confirms the importance of this plant as a potential cause of occupational asthma in the floral industry. PMID:2384649

  20. Gated CT imaging using a free-breathing respiration signal from flow-volume spirometry

    SciTech Connect

    D'Souza, Warren D.; Kwok, Young; Deyoung, Chad; Zacharapoulos, Nicholas; Pepelea, Mark; Klahr, Paul; Yu, Cedric X.

    2005-12-15

    Respiration-induced tumor motion is known to cause artifacts on free-breathing spiral CT images used in treatment planning. This leads to inaccurate delineation of target volumes on planning CT images. Flow-volume spirometry has been used previously for breath-holds during CT scans and radiation treatments using the active breathing control (ABC) system. We have developed a prototype by extending the flow-volume spirometer device to obtain gated CT scans using a PQ 5000 single-slice CT scanner. To test our prototype, we designed motion phantoms to compare image quality obtained with and without gated CT scan acquisition. Spiral and axial (nongated and gated) CT scans were obtained of phantoms with motion periods of 3-5 s and amplitudes of 0.5-2 cm. Errors observed in the volume estimate of these structures were as much as 30% with moving phantoms during CT simulation. Application of motion-gated CT with active breathing control reduced these errors to within 5%. Motion-gated CT was then implemented in patients and the results are presented for two clinical cases: lung and abdomen. In each case, gated scans were acquired at end-inhalation, end-exhalation in addition to a conventional free-breathing (nongated) scan. The gated CT scans revealed reduced artifacts compared with the conventional free-breathing scan. Differences of up to 20% in the volume of the structures were observed between gated and free-breathing scans. A comparison of the overlap of structures between the gated and free-breathing scans revealed misalignment of the structures. These results demonstrate the ability of flow-volume spirometry to reduce errors in target volumes via gating during CT imaging.

  1. 42 CFR 84.81 - Compressed breathing gas and liquefied breathing gas containers; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Compressed breathing gas and liquefied breathing gas containers; minimum requirements. 84.81 Section 84.81 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE...

  2. Blinded Validation of Breath Biomarkers of Lung Cancer, a Potential Ancillary to Chest CT Screening

    PubMed Central

    Phillips, Michael; Bauer, Thomas L.; Cataneo, Renee N.; Lebauer, Cassie; Mundada, Mayur; Pass, Harvey I.; Ramakrishna, Naren; Rom, William N.; Vallières, Eric

    2015-01-01

    Background Breath volatile organic compounds (VOCs) have been reported as biomarkers of lung cancer, but it is not known if biomarkers identified in one group can identify disease in a separate independent cohort. Also, it is not known if combining breath biomarkers with chest CT has the potential to improve the sensitivity and specificity of lung cancer screening. Methods Model-building phase (unblinded): Breath VOCs were analyzed with gas chromatography mass spectrometry in 82 asymptomatic smokers having screening chest CT, 84 symptomatic high-risk subjects with a tissue diagnosis, 100 without a tissue diagnosis, and 35 healthy subjects. Multiple Monte Carlo simulations identified breath VOC mass ions with greater than random diagnostic accuracy for lung cancer, and these were combined in a multivariate predictive algorithm. Model-testing phase (blinded validation): We analyzed breath VOCs in an independent cohort of similar subjects (n = 70, 51, 75 and 19 respectively). The algorithm predicted discriminant function (DF) values in blinded replicate breath VOC samples analyzed independently at two laboratories (A and B). Outcome modeling: We modeled the expected effects of combining breath biomarkers with chest CT on the sensitivity and specificity of lung cancer screening. Results Unblinded model-building phase. The algorithm identified lung cancer with sensitivity 74.0%, specificity 70.7% and C-statistic 0.78. Blinded model-testing phase: The algorithm identified lung cancer at Laboratory A with sensitivity 68.0%, specificity 68.4%, C-statistic 0.71; and at Laboratory B with sensitivity 70.1%, specificity 68.0%, C-statistic 0.70, with linear correlation between replicates (r = 0.88). In a projected outcome model, breath biomarkers increased the sensitivity, specificity, and positive and negative predictive values of chest CT for lung cancer when the tests were combined in series or parallel. Conclusions Breath VOC mass ion biomarkers identified lung cancer in a

  3. Experimental and modeling study of thermal exposure of a self-contained breathing apparatus (SCBA).

    PubMed

    Donnelly, Michelle K; Yang, Jiann C

    2015-08-01

    An experimental apparatus designed to study firefighter safety equipment exposed to a thermal environment was developed. The apparatus consisted of an elevated temperature flow loop with the ability to heat the air stream up to 200°C. The thermal and flow conditions at the test section were characterized using thermocouples and bi-directional probes. The safety equipment examined in this study was a self-contained breathing apparatus (SCBA), including a facepiece and an air cylinder. The SCBA facepiece was placed on a mannequin headform and coupled to a breathing simulator that was programmed with a prescribed breathing pattern. The entire SCBA assembly was placed in the test section of the flow loop for these thermal exposure experiments. Three air stream temperatures, 100°C, 150°C, and 200°C, were used with the average air speed at the test section set at 1.4m/s and thermal exposure durations up to 1200 s. Measurements were made using type-K bare-bead thermocouples located in the mannequin's mouth and on the outer surface of the SCBA cylinder. The experimental results indicated that increasing the thermal exposure severity and duration increased the breathing air temperatures supplied by the SCBA. Temperatures of breathing air from the SCBA cylinder in excess of 60°C were observed over the course of the thermal exposure conditions used in most of the experiments. A mathematical model for transient heat transfer was developed to complement the thermal exposure experimental study. The model took into consideration forced convective heat transfer, quasi-steady heat conduction through the composite layers of the SCBA cylinder wall, the breathing pattern and action of the breathing simulator, and predicted air temperatures from the thermally exposed SCBA cylinder and temperatures at the outer surface of the SCBA cylinder. Model predictions agreed reasonably well with the experimental measurements. PMID:25681021

  4. Attraction of the tropical bont tick, Amblyomma variegatum, to human breath and to the breath components acetone, NO and CO2

    NASA Astrophysics Data System (ADS)

    McMahon, C.; Guerin, P. M.

    2002-04-01

    Ticks are of medical and veterinary importance and employ several cues in search of a host. Olfaction is one modality by which ticks locate a blood-meal and breath is the major vent of gaseous and volatile metabolites from the host that could contribute to this search. We studied the responses of a hunter tick, Amblyomma variegatum, to diluted human breath and five of its components (acetone, CO2, NO, isoprene and NH3) while walking in an air stream on a locomotion compensator. Diluted breath elicited the greatest responses of all treatments in terms of time to onset of upwind walk, attraction, speed and local search behaviour after stimulus off. Acetone, NO and CO2 also attracted, but with a reduced speed in the case of acetone and NO. Neither isoprene nor NH3 induced any response. Our study indicates that breath was the most adequate stimulus tested. It also attracted two other ixodid tick species, Rhipicephalus sanguineus and Ixodes ricinus, as well as the argasid tick, Ornithodorus moubata. It appears that the evolution of resource tracking in ticks included sensory and behavioural adaptations for recognition and orientation to host metabolites that are regularly expelled in breath.

  5. Ecological sounds affect breath duration more than artificial sounds.

    PubMed

    Murgia, Mauro; Santoro, Ilaria; Tamburini, Giorgia; Prpic, Valter; Sors, Fabrizio; Galmonte, Alessandra; Agostini, Tiziano

    2016-01-01

    Previous research has demonstrated that auditory rhythms affect both movement and physiological functions. We hypothesized that the ecological sounds of human breathing can affect breathing more than artificial sounds of breathing, varying in tones for inspiration and expiration. To address this question, we monitored the breath duration of participants exposed to three conditions: (a) ecological sounds of breathing, (b) artificial sounds of breathing having equal temporal features as the ecological sounds, (c) no sounds (control). We found that participants' breath duration variability was reduced in the ecological sound condition, more than in the artificial sound condition. We suggest that ecological sounds captured the timing of breathing better than artificial sounds, guiding as a consequence participants' breathing. We interpreted our results according to the Theory of Event Coding, providing further support to its validity, and suggesting its possible extension in the domain of physiological functions which are both consciously and unconsciously controlled. PMID:25637249

  6. Pulse Ejection Presentation System Synchronized with Breathing

    NASA Astrophysics Data System (ADS)

    Kadowaki, Ami; Sato, Junta; Ohtsu, Kaori; Bannai, Yuichi; Okada, Kenichi

    Trials on transmission of olfactory information together with audio/visual information are currently being conducted in the field of multimedia. However, continuous emission of scents in high concentration creates problems of human adaptation and remnant odors in air. To overcome such problems we developed an olfactory display in conjunction with Canon Inc. This display has high emission control in the ink-jet so that it can provide stable pulse emission of scents. Humans catch a scent when they breathe in and inhale smell molecules in air. Therefore, it is important that the timing of scent presentation is synchronized with human breathing. We also developed a breath sensor which detects human inspiration. In this study, we combined the olfactory display with the breath sensor to make a pulse ejection presentation system synchronized the breath. The experimental evaluation showed that the system had more than 90 percent of detection rate. Another evaluation was held at KEIO TECHNO-MALL 2007. From questionnaire results of the participants, we found that the system made the user feel continuous sense of smell avoiding adaptation. It is expected that our system enables olfactory information to be synchronized with audio/visual information in arbitrary duration at any time.

  7. Sudarshan kriya yoga: Breathing for health

    PubMed Central

    Zope, Sameer A.; Zope, Rakesh A

    2013-01-01

    Breathing techniques are regularly recommended for relaxation, stress management, control of psychophysiological states, and to improve organ function. Yogic breathing, defined as a manipulation of breath movement, has been shown to positively affect immune function, autonomic nervous system imbalances, and psychological or stress-related disorders. The aim of this study was to assess and provide a comprehensive review of the physiological mechanisms, the mind–body connection, and the benefits of Sudarshan Kriya Yoga (SKY) in a wide range of clinical conditions. Various online databases searched were Medline, Psychinfo, EMBASE, and Google Scholar. All the results were carefully screened and articles on SKY were selected. The references from these articles were checked to find any other potentially relevant articles. SKY, a unique yogic breathing practice, involves several types of cyclical breathing patterns, ranging from slow and calming to rapid and stimulating. There is mounting evidence to suggest that SKY can be a beneficial, low-risk, low-cost adjunct to the treatment of stress, anxiety, post-traumatic stress disorder, depression, stress-related medical illnesses, substance abuse, and rehabilitation of criminal offenders. PMID:23440614

  8. Sudarshan kriya yoga: Breathing for health.

    PubMed

    Zope, Sameer A; Zope, Rakesh A

    2013-01-01

    Breathing techniques are regularly recommended for relaxation, stress management, control of psychophysiological states, and to improve organ function. Yogic breathing, defined as a manipulation of breath movement, has been shown to positively affect immune function, autonomic nervous system imbalances, and psychological or stress-related disorders. The aim of this study was to assess and provide a comprehensive review of the physiological mechanisms, the mind-body connection, and the benefits of Sudarshan Kriya Yoga (SKY) in a wide range of clinical conditions. Various online databases searched were Medline, Psychinfo, EMBASE, and Google Scholar. All the results were carefully screened and articles on SKY were selected. The references from these articles were checked to find any other potentially relevant articles. SKY, a unique yogic breathing practice, involves several types of cyclical breathing patterns, ranging from slow and calming to rapid and stimulating. There is mounting evidence to suggest that SKY can be a beneficial, low-risk, low-cost adjunct to the treatment of stress, anxiety, post-traumatic stress disorder, depression, stress-related medical illnesses, substance abuse, and rehabilitation of criminal offenders. PMID:23440614

  9. eAMI: A Qualitative Quantification of Periodic Breathing Based on Amplitude of Oscillations

    PubMed Central

    Fernandez Tellez, Helio; Pattyn, Nathalie; Mairesse, Olivier; Dolenc-Groselj, Leja; Eiken, Ola; Mekjavic, Igor B.; Migeotte, P. F.; Macdonald-Nethercott, Eoin; Meeusen, Romain; Neyt, Xavier

    2015-01-01

    Study Objectives: Periodic breathing is sleep disordered breathing characterized by instability in the respiratory pattern that exhibits an oscillatory behavior. Periodic breathing is associated with increased mortality, and it is observed in a variety of situations, such as acute hypoxia, chronic heart failure, and damage to respiratory centers. The standard quantification for the diagnosis of sleep related breathing disorders is the apnea-hypopnea index (AHI), which measures the proportion of apneic/hypopneic events during polysomnography. Determining the AHI is labor-intensive and requires the simultaneous recording of airflow and oxygen saturation. In this paper, we propose an automated, simple, and novel methodology for the detection and qualification of periodic breathing: the estimated amplitude modulation index (eAMI). Patients or Participants: Antarctic cohort (3,800 meters): 13 normal individuals. Clinical cohort: 39 different patients suffering from diverse sleep-related pathologies. Measurements and Results: When tested in a population with high levels of periodic breathing (Antarctic cohort), eAMI was closely correlated with AHI (r = 0.95, P < 0.001). When tested in the clinical setting, the proposed method was able to detect portions of the signal in which subclinical periodic breathing was validated by an expert (n = 93; accuracy = 0.85). Average eAMI was also correlated with the loop gain for the combined clinical and Antarctica cohorts (r = 0.58, P < 0.001). Conclusions: In terms of quantification and temporal resolution, the eAMI is able to estimate the strength of periodic breathing and the underlying loop gain at any given time within a record. The impaired prognosis associated with periodic breathing makes its automated detection and early diagnosis of clinical relevance. Citation: Fernandez Tellez H, Pattyn N, Mairesse O, Dolenc-Groselj L, Eiken O, Mekjavic IB, Migeotte PF, Macdonald-Nethercott E, Meeusen R, Neyt X. eAMI: a qualitative

  10. Technologies for Clinical Diagnosis Using Expired Human Breath Analysis

    PubMed Central

    Mathew, Thalakkotur Lazar; Pownraj, Prabhahari; Abdulla, Sukhananazerin; Pullithadathil, Biji

    2015-01-01

    This review elucidates the technologies in the field of exhaled breath analysis. Exhaled breath gas analysis offers an inexpensive, noninvasive and rapid method for detecting a large number of compounds under various conditions for health and disease states. There are various techniques to analyze some exhaled breath gases, including spectrometry, gas chromatography and spectroscopy. This review places emphasis on some of the critical biomarkers present in exhaled human breath, and its related effects. Additionally, various medical monitoring techniques used for breath analysis have been discussed. It also includes the current scenario of breath analysis with nanotechnology-oriented techniques. PMID:26854142

  11. Ventilatory response to helium-oxygen breathing during exercise: effect of airway anesthesia.

    PubMed

    Krishnan, B S; Clemens, R E; Zintel, T A; Stockwell, M J; Gallagher, C G

    1997-07-01

    The substitution of a normoxic helium mixture (HeO2) for room air (Air) during exercise results in a sustained hyperventilation, which is present even in the first breath. We hypothesized that this response is dependent on intact airway afferents; if so, airway anesthesia (Anesthesia) should affect this response. Anesthesia was administered to the upper airways by topical application and to lower central airways by aerosol inhalation and was confirmed to be effective for over 15 min. Subjects performed constant work-rate exercise (CWE) at 69 +/- 2 (SE) % maximal work rate on a cycle ergometer on three separate days: twice after saline inhalation (days 1 and 3) and once after Anesthesia (day 2). CWE commenced after a brief warm-up, with subjects breathing Air for the first 5 min (Air-1), HeO2 for the next 3 min, and Air again until the end of CWE (Air-2). The resistance of the breathing circuit was matched for Air and HeO2. Breathing HeO2 resulted in a small but significant increase in minute ventilation (VI) and decrease in alveolar PCO2 in both the Saline (average of 2 saline tests; not significant) and Anesthesia tests. Although Anesthesia had no effect on the sustained hyperventilatory response to HeO2 breathing, the VI transients within the first six breaths of HeO2 were significantly attenuated with Anesthesia. We conclude that the VI response to HeO2 is not simply due to a reduction in external tubing resistance and that, in humans, airway afferents mediate the transient but not the sustained hyperventilatory response to HeO2 breathing during exercise. PMID:9216948

  12. Effect of dietary turmeric on breath hydrogen.

    PubMed

    Shimouchi, Akito; Nose, Kazutoshi; Takaoka, Motoko; Hayashi, Hiroko; Kondo, Takaharu

    2009-08-01

    Turmeric is widely used in Indian cuisine. The main constituents of turmeric are curcumin and its analogues, which are well-known antioxidant compounds. In the present study, we hypothesized that turmeric in curry might increase bowel motility and activate hydrogen-producing bacterial flora in the colon, thereby increasing the concentration of breath hydrogen. Eight healthy subjects fasted for 12 h and ingested curry and rice with or without turmeric (turmeric knockout curry). Breath-hydrogen concentrations were analyzed every 15 min for 6 h by gas chromatography with a semiconductor detector. Curry with turmeric significantly increased the area under the curve of breath hydrogen and shortened small-bowel transit time, compared with curry not containing turmeric. These results suggested that dietary turmeric activated bowel motility and carbohydrate colonic fermentation. PMID:19034660

  13. Sleep and Breathing at High Altitude.

    PubMed

    Wickramasinghe, Himanshu; Anholm, James D.

    1999-01-01

    Sleep at high altitude is characterized by poor subjective quality, increased awakenings, frequent brief arousals, marked nocturnal hypoxemia, and periodic breathing. A change in sleep architecture with an increase in light sleep and decreasing slow-wave and REM sleep have been demonstrated. Periodic breathing with central apnea is almost universally seen amongst sojourners to high altitude, although it is far less common in long-standing high altitude dwellers. Hypobaric hypoxia in concert with periodic breathing appears to be the principal cause of sleep disruption at altitude. Increased sleep fragmentation accounts for the poor sleep quality and may account for some of the worsened daytime performance at high altitude. Hypoxic sleep disruption contributes to the symptoms of acute mountain sickness. Hypoxemia at high altitude is most severe during sleep. Acetazolamide improves sleep, AMS symptoms, and hypoxemia at high altitude. Low doses of a short acting benzodiazepine (temazepam) may also be useful in improving sleep in high altitude. PMID:11898114

  14. Modeling of deep breath vasoconstriction reflex.

    PubMed

    Chalacheva, Patjanaporn; Khoo, Michael C K

    2015-08-01

    Deep breaths akin to sighs have been reported to cause peripheral vasoconstriction. Our previous simulation studies have shown that this phenomenon cannot be reproduced in existing circulatory control models without inclusion of a respiratory-vascular coupling mechanism. To better understand this "sigh-vasoconstriction reflex", we investigated the effect of spontaneous and passively induced sighs as well as spontaneous breathing on peripheral vasoconstriction during wakefulness and non-rapid eye movement sleep in human subjects. We found that both spontaneous and induced sighs caused vasoconstriction during wakefulness and sleep. The coupling between respiration and vasoconstriction is also present even in an absence of deep breaths. The coupling mechanism is largely linear with increased nonlinearity during induced sighs. Since peripheral vascular resistance modulation is known to be sympathetically mediated, investigation of this coupling could potentially allow us to assess sympathetic function through non-invasive measurements and simple interventions. PMID:26738099

  15. New Approaches to Diagnosing Sleep-Disordered Breathing.

    PubMed

    Sands, Scott A; Owens, Robert L; Malhotra, Atul

    2016-06-01

    Novel concepts and technological advances have the potential to change the landscape on which clinical sleep medicine is practiced. Screening for sleep apnea will take advantage of readily available mobile telephone technology (sound, accelerometers) to enable widespread recognition of sleep-disordered breathing. Advanced computer-assisted scoring algorithms will improve efficiency and reliability of sleep apnea diagnoses. As the field adopts a personalized approach to therapies, methods to determine the mechanisms of sleep apnea in individuals will be developed-utilizing simplified tests and available recordings-with the promise of predicting outcomes of novel therapies. PMID:27236052

  16. Hemispherical breathing mode speaker using a dielectric elastomer actuator.

    PubMed

    Hosoya, Naoki; Baba, Shun; Maeda, Shingo

    2015-10-01

    Although indoor acoustic characteristics should ideally be assessed by measuring the reverberation time using a point sound source, a regular polyhedron loudspeaker, which has multiple loudspeakers on a chassis, is typically used. However, such a configuration is not a point sound source if the size of the loudspeaker is large relative to the target sound field. This study investigates a small lightweight loudspeaker using a dielectric elastomer actuator vibrating in the breathing mode (the pulsating mode such as the expansion and contraction of a balloon). Acoustic testing with regard to repeatability, sound pressure, vibration mode profiles, and acoustic radiation patterns indicate that dielectric elastomer loudspeakers may be feasible. PMID:26520355

  17. Decompression sickness following breath-hold diving.

    PubMed

    Schipke, J D; Gams, E; Kallweit, Oliver

    2006-01-01

    Despite convincing evidence of a relationship between breath-hold diving and decompression sickness (DCS), the causal connection is only slowly being accepted. Only the more recent textbooks have acknowledged the risks of repetitive breath-hold diving. We compare four groups of breath-hold divers: (1) Japanese and Korean amas and other divers from the Pacific area, (2) instructors at naval training facilities, (3) spear fishers, and (4) free-dive athletes. While the number of amas is likely decreasing, and Scandinavian Navy training facilities recorded only a few accidents, the number of spear fishers suffering accidents is on the rise, in particular during championships or using scooters. Finally, national and international associations (e.g., International Association of Free Drives [IAFD] or Association Internationale pour Le Developpment De L'Apnee [AIDA]) promote free-diving championships including deep diving categories such as constant weight, variable weight, and no limit. A number of free-diving athletes, training for or participating in competitions, are increasingly accident prone as the world record is presently set at a depth of 171 m. This review presents data found after searching Medline and ISI Web of Science and using appropriate Internet search engines (e.g., Google). We report some 90 cases in which DCS occurred after repetitive breath-hold dives. Even today, the risk of suffering from DCS after repetitive breath-hold diving is often not acknowledged. We strongly suggest that breath-hold divers and their advisors and physicians be made aware of the possibility of DCS and of the appropriate therapeutic measures to be taken when DCS is suspected. Because the risk of suffering from DCS increases depending on depth, bottom time, rate of ascent, and duration of surface intervals, some approaches to assess the risks are presented. Regrettably, none of these approaches is widely accepted. We propose therefore the development of easily manageable

  18. Electrospray ionization of volatiles in breath

    NASA Astrophysics Data System (ADS)

    Martínez-Lozano, P.; de La Mora, J. Fernández

    2007-08-01

    Recent work by Zenobi and colleagues [H. Chen, A. Wortmann, W. Zhang, R. Zenobi, Angew. Chem. Int. Ed. 46 (2007) 580] reports that human breath charged by contact with an electrospray (ES) cloud yields many mass peaks of species such as urea, glucose, and other ions, some with molecular weights above 1000 Da. All these species are presumed to be involatile, and to originate from breath aerosols by so-called extractive electrospray ionization EESI [H. Chen, A. Venter, R.G. Cooks, Chem. Commun. (2006) 2042]. However, prior work by Fenn and colleagues [C.M. Whitehouse, F. Levin, C.K. Meng, J.B. Fenn, Proceedings of the 34th ASMS Conference on Mass Spectrometry and Allied Topics, Denver, 1986 p. 507; S. Fuerstenau, P. Kiselev, J.B. Fenn, Proceedings of the 47th ASMS Conference on Mass Spectrometry, 1999, Dallas, TX, 1999] and by Hill and colleagues [C. Wu, W.F. Siems, H.H. Hill Jr., Anal. Chem. 72 (2000) 396] have reported the ability of electrospray drops to ionize a variety of low vapor pressure substances directly from the gas phase, without an apparent need for the vapor to be brought into the charging ES in aerosol form. The Ph.D. Thesis of Martínez-Lozano [P. Martínez-Lozano Sinués, Ph.D. Thesis, Department of Thermal and Fluid Engineering, University Carlos III of Madrid; April 5, 2006 (in Spanish); http://hdl.handle.net/10016/655] had also previously argued that the numerous human breath species observed via a similar ES ionization approach were in fact ionized directly from the vapor. Here, we observe that passage of the breath stream through a submicron filter does not eliminate the majority of the breath vapors seen in the absence of the filter. We conclude that direct vapor charging is the leading mechanism in breath ionization by electrospray drops, though aerosol ionization may also play a role.

  19. Current diagnostic trends in sleep disordered breathing

    PubMed Central

    Maurer, Joachim T.

    2006-01-01

    Over the past two decades, various methods of sophisticated diagnostics of the upper airway have been tested in patients with sleep disordered breathing (SDB). In this context, endoscopic techniques and pharyngeal pressure recordings are of special interest for the otorhinolaryngologist. Whereas the basic otorhinolaryngological examination is able to detect anatomical pathologies which need to and can be corrected, the Müller-Manoeuvre seems to help exclude patients from uvulopalatopharyngoplasty. To a large extent, videoendoscopy during natural sleep has been replaced by videoendoscopy under sedation. Despite good methodological preparation and impressive presentability of the obstructions, there is not sufficent evidence to demonstrate that videoendoscopy under sedation improves the success rate of surgery in SDB. However, in assessing the impact of the epiglottis on upper airway obstructions in the individual patient, videoendoscopy is the only existing option. Multi-channel pressure recordings permit analysing the entire sleep period and are well tolerated. They can be used to determine the Apnea-Hypopnea-Index as well as to quantify obstructive events in the upper and lower pharyngeal segment. On the other hand, obstructions of the tongue base cannot be distinguished from obstructions related to the epiglottis. According to the data available so far, the benefit of sophisticated diagnostics of the upper airway still has to be judged with caution. Therefore, the promising approaches of both videoendoscopy under sedation and multi-channel pressure recordings deserve further intensive research. According to the personal estimation of the author, they will nevertheless become valuable tools for otorhinolaryngologists in the near future, thus complementing the basic ENT-examination and improving the treatment of patients. PMID:22073071

  20. A breathing mode for warped compactifications

    NASA Astrophysics Data System (ADS)

    Underwood, Bret

    2011-10-01

    In general warped compactifications, non-trivial backgrounds for the warp factor and the dilaton break D-dimensional diffeomorphism invariance, so that dilaton fluctuations can be gauged away completely and eaten by the metric. More specifically, the warped volume modulus and the dilaton are not independent, but combine into a single gauge-invariant degree of freedom in the lower dimensional effective theory, the warped breathing mode. This occurs for all strengths of the warping, even the weakly warped limit. This warped breathing mode appears as a natural zero mode deformation of backgrounds sourced by p-branes and affects the identification of the independent degrees of freedom of flux compactifications.

  1. Blood and breath levels of selected volatile organic compounds in healthy volunteers

    PubMed Central

    King, Julian; Klieber, Martin; Unterkofler, Karl; Hinterhuber, Hartmann; Baumann, Matthias

    2016-01-01

    Gas chromatography with mass spectrometric detection (GC-MS) was used to identify and quantify volatile organic compounds in the blood and breath of healthy individuals. Blood and breath volatiles were preconcentrated using headspace solid phase micro-extraction (HS-SPME) and needle trap devices (NTDs), respectively. The study involved a group of 28 healthy test subjects and resulted in the quantification of a total of 74 compounds in both types of samples. The concentrations of the species under study varied between 0.01 and 6700 nmol L−1 in blood and between 0.02 and 2500 ppb in exhaled air. Limits of detection (LOD) ranged from 0.01 to 270 nmol L−1 for blood compounds and from 0.01 to 0.7 ppb for breath species. Relative standard deviations for both measurement regimes varied from 1.5 to 14%. The predominant chemical classes among the compounds quantified were hydrocarbons (24), ketones (10), terpenes (8), heterocyclic compounds (7) and aromatic compounds (7). Twelve analytes were found to be highly present in both blood and exhaled air (with incidence rates higher than 80%) and for 32 species significant differences (Wilcoxon signed-rank test) between room air and exhaled breath were observed. By comparing blood, room air and breath levels in parallel, a tentative classification of volatiles into endogenous and exogenous compounds can be achieved. PMID:23435188

  2. Oxygen related chemoreceptor drive to breathe during H2S infusion

    PubMed Central

    Philippe, Haouzi; Sonobe, Takashi; Chenuel, Bruno

    2014-01-01

    This study addresses the following question: Could the acute depression in breathing produced by hyperoxia, a reflection of the tonic drive to breathe from the arterial chemoreceptors, be accounted for by the presence a background level of local endogenous H2S? To address this question, we produced a stable but moderate increase in breathing (24 ± 11%) via continuous infusion of low levels of H2S, in 10 spontaneously breathing urethane-sedated rats. We found that acute exposure to 100% O2 (20 tests) decreased minute ventilation (VI) from 301 ± 51 to 210 ± 43 ml/min within 15 seconds in control conditions, but no additional significant drop in VI was observed during H2S induced hyperpnea. In addition, no decrease in the estimated concentrations of gaseous H2S in the arterial blood was observed during the hyperoxic tests. It is concluded that the ventilatory depression induced by high O2 appears to be limited to the tonic background peripheral chemosensory drive to breathe, but has little or no impact on the CB stimulation produced by low levels of H2S. PMID:24973475

  3. Flute ``breath support'' perception and its acoustical correlates

    NASA Astrophysics Data System (ADS)

    Cossette, Isabelle A.; Sabourin, Patrick

    2001-05-01

    Music educators and performers commonly refer to ``breath support'' in flute playing, yet the term ``support'' is neither well-defined nor consistently used. Different breathing strategies used by professional flautists who were instructed to play with and without support were previously identified by the authors. In the current study, 14 musical excerpts with and without support were recorded by five professional flautists. Eleven professional flautists listened to the recordings in a random order and ranked (1 to 6) how much of the following sound qualities they judged to be in each example: support, intonation, control and musical expressiveness. Answers to the test showed that musical expressiveness was associated more closely with the supported excerpts than the answers about support itself. The ratings for each sound quality were highly intercorrelated. Acoustical parameters were analyzed (frequency and centroid variation within each note) and compared with the results of the perception test in order to better understand how the acoustical and psychological variables were related. The acoustical analysis of the central part of the notes did not show evident correlation with the answers of the perception test. [Work funded by the Social Sciences and Humanities Research Council of Canada.

  4. nuMoM2b Sleep Disordered Breathing Study: Objectives and Methods

    PubMed Central

    Facco, Francesca L.; Parker, Corette B.; Reddy, Uma M.; Silver, Robert M.; Louis, Judette M.; Basner, Robert C.; Chung, Judith H.; Schubert, Frank P.; Pien, Grace W.; Redline, Susan; Mobley, Daniel; Koch, Matthew A.; Simhan, Hyagriv N.; Chia-Ling, Nhan-Chang; Parry, Samuel; Grobman, William A.; Haas, David M.; Wing, Deborah A.; Mercer, Brian M.; Saade, George R.; Zee, Phyllis C.

    2015-01-01

    Objective The objective of the Sleep Disordered Breathing substudy of the Nulliparous Pregnancy Outcomes Study Monitoring Mothers-to-be (nuMoM2b) is to determine whether sleep disordered breathing during pregnancy is a risk factor for adverse pregnancy outcomes. Methods nuMoM2b is a prospective cohort study of 10,037 nulliparous women with singleton gestations, conducted across 8 sites, with a central Data Coordinating and Analysis Center. The Sleep Disordered Breathing substudy recruited 3702 women from the cohort to undergo objective, overnight in-home assessments of sleep disordered breathing. A standardized Level 3 home sleep test was performed between 60–150 weeks of pregnancy (Visit 1) and again between 220–310 weeks of pregnancy (Visit 3). Scorings of tests were conducted by a central Sleep Reading Center. Participants and their health care providers were notified if test results met “urgent referral” criteria based on threshold levels of apnea hypopnea indices, oxygen saturation levels or ECG abnormalities, but otherwise were not notified of test results. The primary pregnancy outcomes to be analyzed in relation to maternal sleep disordered breathing are preeclampsia, gestational hypertension, gestational diabetes, fetal growth restriction, and preterm birth. Results Objective data were obtained at Visit 1 on 3261 women, 88.1% of studies attempted; and at Visit 3 on 2511 women, 87.6% of studies attempted. Basic characteristics of the substudy cohort are reported in this methods paper. Conclusion The substudy is designed to address important questions regarding the relationship of sleep disordered breathing on the risk of preeclampsia and other outcomes of relevance to maternal and child health. PMID:25746730

  5. Coughing Wheezing Shortness of Breath Tightness in Chest

    MedlinePlus

    ... Issues Coughing Wheezing Shortness of Breath Tightness in Chest Past Issues / Fall 2006 Table of Contents For ... short of breath or feel tightness in your chest, you might have asthma. If you do, you ...

  6. 42 CFR 84.115 - Breathing tubes; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Gas Masks § 84.115 Breathing tubes; minimum requirements. Flexible breathing tubes used in conjunction with...

  7. 42 CFR 84.115 - Breathing tubes; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Gas Masks § 84.115 Breathing tubes; minimum requirements. Flexible breathing tubes used in conjunction with...

  8. 42 CFR 84.115 - Breathing tubes; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Gas Masks § 84.115 Breathing tubes; minimum requirements. Flexible breathing tubes used in conjunction with...

  9. 42 CFR 84.115 - Breathing tubes; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Gas Masks § 84.115 Breathing tubes; minimum requirements. Flexible breathing tubes used in conjunction with...

  10. Coughing Wheezing Shortness of Breath Tightness in Chest

    MedlinePlus

    ... Current Issue Past Issues Coughing Wheezing Shortness of Breath Tightness in Chest Past Issues / Fall 2006 Table ... you cough a lot, wheeze, are short of breath or feel tightness in your chest, you might ...

  11. Meeting Reports for 2013: Recent Advances in Breath Biomarker Research

    EPA Science Inventory

    This article reports the efforts of the breath research community affiliated with the International Association of Breath Research (IABR) in disseminating research results in high profile technical meetings in the United States (US). Specifically, we describe presentations at a ...

  12. ALVEOLAR BREATH SAMPLING AND ANALYSIS IN HUMAN EXPOSURE ASSESSMENT STUDIES

    EPA Science Inventory

    Alveolar breath sampling and analysis can be extremely useful in exposure assessment studies involving volatile organic compounds (VOCs). Over recent years scientists from the EPA's National Exposure Research Laboratory have developed and refined an alveolar breath collection ...

  13. Differences in spontaneous breathing pattern and mechanics in patients with severe COPD recovering from acute exacerbation.

    PubMed

    Vitacca, M; Porta, R; Bianchi, L; Clini, E; Ambrosino, N

    1999-02-01

    The aims of this study were to assess spontaneous breathing patterns in patients with chronic obstructive pulmonary disease (COPD) recovering from acute exacerbation and to assess the relationship between different breathing patterns and clinical and functional parameters of respiratory impairment. Thirty-four COPD patients underwent assessment of lung function tests, arterial blood gases, haemodynamics, breathing pattern (respiratory frequency (fR), tidal volume (VT), inspiratory and expiratory time (tI and tE), duty cycle (tI/ttot), VT/tI) and mechanics (oesophageal pressure (Poes), work of breathing (WOB), pressure-time product and index, and dynamic intrinsic positive end-expiratory pressure (PEEPi,dyn)). According to the presence (group 1) or absence (group 2) of Poes swings during the expiratory phase (premature inspiration), 20 (59%) patients were included in group 1 and 14 (41%) in group 2. Premature inspirations were observed 4.5+/-6.4 times x min(-1) (range 1-31), i.e. 20+/-21% (3.7-100%) of total fR calculated from VT tracings. In group 1 the coefficient of variation in VT, tE, tI/ttot, PEEPi,dyn, Poes and WOB of the eight consecutive breaths immediately preceding the premature inspiration was greater than that of eight consecutive breaths in group 2. There were no significant differences in the assessed parameters between the two groups in the overall population, whereas patients with chronic hypoxaemia in group 1 showed a more severe impairment in clinical conditions, mechanics and lung function than hypoxaemic patients in group 2. In spontaneously breathing patients with chronic obstructive pulmonary disease recovering from an acute exacerbation, detectable activity of inspiratory muscles during expiration was found in more than half of the cases. This phenomenon was not associated with any significant differences in anthropometric, demographic, physiological or clinical characteristics. PMID:10065683

  14. Design and Evaluation of a Breath Analysis System for Occupational Exposure Assessment

    SciTech Connect

    Soldat, Kelvin L.; Thrall, Karla D.

    2001-06-01

    Exposure assessment is an integral part of industrial hygiene and occupational health. To ensure the health and safety of workers, integrated industrial hygiene methodologies often include biological monitoring strategies. Exhaled breath is an ideal matrix for measuring volatile biomarkers, particularly since the non-invasive collection of breath may improve volunteer participation. A real-time, field-portable system was developed to analyze undiluted exhaled air from experimental animals and humans. The system combines (1) an ion-trap mass spectrometer capable of atmospheric sampling; (2) a breath interface for continual analysis of the exhaled breath stream; (3) chemical dosimeters that are analyzed in the field/workplace; and (4) physiologically based pharmacokinetic (PBPK) models to estimate total exposure and internal target tissue dosimetry. The intent of this development was to provide new instrumentation to evaluate volatile chemical exposures as part of a daily monitoring pro gram. For example, the system was designed to monitor a worker every time they enter and leave a work environment - a vast improvement over current 8-hr integrated monitoring strategies. To evaluate the system in actual work environments, field tests were conducted using volunteers providing exhaled breath samples before and after each specific job task. In these field studies, several volunteers had post-task breath levels higher than pre-task levels. Compared to the breath analysis findings, chemical dosimeters underpredicted exposures, particularly for longer sampling intervals where the volume of air sampled may have diluted exposures. The results of these field studies illustrate the utility of monitoring workers for exposures at numerous times throughout the day, particularly when job-specific tasks may indicate a potential for exposure.

  15. The cerebral cost of breathing: an FMRI case-study in congenital central hypoventilation syndrome.

    PubMed

    Sharman, Mike; Gallea, Cécile; Lehongre, Katia; Galanaud, Damien; Nicolas, Nathalie; Similowski, Thomas; Cohen, Laurent; Straus, Christian; Naccache, Lionel

    2014-01-01

    Certain motor activities--like walking or breathing--present the interesting property of proceeding either automatically or under voluntary control. In the case of breathing, brainstem structures located in the medulla are in charge of the automatic mode, whereas cortico-subcortical brain networks--including various frontal lobe areas--subtend the voluntary mode. We speculated that the involvement of cortical activity during voluntary breathing could impact both on the "resting state" pattern of cortical-subcortical connectivity, and on the recruitment of executive functions mediated by the frontal lobe. In order to test this prediction we explored a patient suffering from central congenital hypoventilation syndrome (CCHS), a very rare developmental condition secondary to brainstem dysfunction. Typically, CCHS patients demonstrate efficient cortically-controlled breathing while awake, but require mechanically-assisted ventilation during sleep to overcome the inability of brainstem structures to mediate automatic breathing. We used simultaneous EEG-fMRI recordings to compare patterns of brain activity between these two types of ventilation during wakefulness. As compared with spontaneous breathing (SB), mechanical ventilation (MV) restored the default mode network (DMN) associated with self-consciousness, mind-wandering, creativity and introspection in healthy subjects. SB on the other hand resulted in a specific increase of functional connectivity between brainstem and frontal lobe. Behaviorally, the patient was more efficient in cognitive tasks requiring executive control during MV than during SB, in agreement with her subjective reports in everyday life. Taken together our results provide insight into the cognitive and neural costs of spontaneous breathing in one CCHS patient, and suggest that MV during waking periods may free up frontal lobe resources, and make them available for cognitive recruitment. More generally, this study reveals how the active

  16. Inhibition of hydrogen sulfide restores normal breathing stability and improves autonomic control during experimental heart failure

    PubMed Central

    Del Rio, Rodrigo; Marcus, Noah J.

    2013-01-01

    Cardiovascular autonomic imbalance and breathing instability are major contributors to the progression of heart failure (CHF). Potentiation of the carotid body (CB) chemoreflex has been shown to contribute to these effects. Hydrogen sulfide (H2S) recently has been proposed to mediate CB hypoxic chemoreception. We hypothesized that H2S synthesis inhibition should decrease CB chemoreflex activation and improve breathing stability and autonomic function in CHF rats. Using the irreversible inhibitor of cystathione γ-lyase dl-propargylglycine (PAG), we tested the effects of H2S inhibition on resting breathing patterns, the hypoxic and hypercapnic ventilatory responses, and the hypoxic sensitivity of CB chemoreceptor afferents in rats with CHF. In addition, heart rate variability (HRV) and systolic blood pressure variability (SBPV) were calculated as an index of autonomic function. CHF rats, compared with sham rats, exhibited increased breath interval variability and number of apneas, enhanced CB afferent discharge and ventilatory responses to hypoxia, decreased HRV, and increased low-frequency SBPV. Remarkably, PAG treatment reduced the apnea index by 90%, reduced breath interval variability by 40–60%, and reversed the enhanced hypoxic CB afferent and chemoreflex responses observed in CHF rats. Furthermore, PAG treatment partially reversed the alterations in HRV and SBPV in CHF rats. Our results show that PAG treatment restores breathing stability and cardiac autonomic function and reduces the enhanced ventilatory and CB chemosensory responses to hypoxia in CHF rats. These results support the idea that PAG treatment could potentially represent a novel pathway to control sympathetic outflow and breathing instability in CHF. PMID:23449938

  17. 49 CFR 219.301 - Testing for reasonable cause.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... breath or body fluid testing, or both, to determine compliance with §§ 219.101 and 219.102 or a railroad... an employee that is required when an employee is required to provide a breath or body fluid specimen... breath testing. In addition to reasonable suspicion as described in § 219.300, the...

  18. 49 CFR 219.301 - Testing for reasonable cause.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... breath or body fluid testing, or both, to determine compliance with §§ 219.101 and 219.102 or a railroad... an employee that is required when an employee is required to provide a breath or body fluid specimen... breath testing. In addition to reasonable suspicion as described in § 219.300, the...

  19. 49 CFR 219.301 - Testing for reasonable cause.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... breath or body fluid testing, or both, to determine compliance with §§ 219.101 and 219.102 or a railroad... an employee that is required when an employee is required to provide a breath or body fluid specimen... breath testing. In addition to reasonable suspicion as described in § 219.300, the...

  20. 49 CFR 219.301 - Testing for reasonable cause.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... breath or body fluid testing, or both, to determine compliance with §§ 219.101 and 219.102 or a railroad... an employee that is required when an employee is required to provide a breath or body fluid specimen... breath testing. In addition to reasonable suspicion as described in § 219.300, the...