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

46 CFR 197.450 - Breathing gas tests.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 7 2013-10-01 2013-10-01 false Breathing gas tests. 197.450 Section 197.450 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE OCCUPATIONAL SAFETY AND HEALTH STANDARDS GENERAL PROVISIONS Commercial Diving Operations Periodic Tests and Inspections of Diving Equipment § 197.450 Breathing gas tests. The diving...

Oxygen-18 isotope of breath CO2 linking to erythrocytes carbonic anhydrase activity: a biomarker for pre-diabetes and type 2 diabetes

PubMed Central

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

2015-01-01

Carbonic anhydrase (CA), a well-characterized metalloenzyme, is associated with oxygen-18 ( 18O)-isotopic fractionations of CO2. To investigate how CA activity links the 18O of breath CO2 to pre-diabetes (PD) and type 2 diabetes (T2D) during metabolism, we studied pre- and post-dose CA activities in erythrocytes with simultaneous monitoring of 18O/ 16O-isotope ratios of breath CO2 and thereafter elucidated potential metabolic pathways underlying CA alteration in the pathogenesis of T2D. Here we show that the post-dose CA activity in both T2D and PD was markedly enhanced, whereas the non-diabetic controls (NDC) exhibited a considerable reduction in post-dose CA activity when compared with their basal CA activities. However, T2D and PD exhibited isotopic enrichments of 18O in breath CO2, while a marked depletion of 18O in CO2 was manifested in NDC. Thus, the isotopic enrichments and depletions of 18O in breath CO2 were well correlated with the changes in CA activities for controls, PD and T2D. Our findings suggest the changes in CA activities in erythrocytes may contribute to the pathogenesis of T2D and the breath C 18O 16O regulated by the CA activity as a potential biomarker for non-invasive assessment of T2D, and thus may open a new method for treating T2D. PMID:25633556

Selective Hydrogen Isotope Separation via Breathing Transition in MIL-53(Al).

PubMed

Kim, Jin Yeong; Zhang, Linda; Balderas-Xicohténcatl, Rafael; Park, Jaewoo; Hirscher, Michael; Moon, Hoi Ri; Oh, Hyunchul

2017-12-13

Breathing of MIL-53(Al), a flexible metal-organic framework (MOF), leads to dynamic changes as narrow pore (np) transitions to large pore (lp). During the flexible and reversible transition, the pore apertures are continuously adjusted, thus providing the tremendous opportunity to separate mixtures of similar-sized and similar-shaped molecules that require precise pore tuning. Herein, for the first time, we report a strategy for effectively separating hydrogen isotopes through the dynamic pore change during the breathing of MIL-53(Al), a representative of flexible MOFs. The experiment shows that the selectivity for D 2 over H 2 is strongly related to the state of the pore structure of MIL-53(Al). The highest selectivity (S D 2 /H 2 = 13.6 at 40 K) was obtained by optimizing the exposure temperature, pressure, and time to systematically tune the pore state of MIL-53(Al).

Performance of the 13C-urea breath test for the diagnosis of H. pylori infection using a substrate synthesized in Brazil: A preliminary study.

PubMed

Coelho, Luiz Gonzaga; Sant'Ana, Carlos Roberto; Oliveira, Ricardo Brandt de; Cezar, Raíra César E; Araujo, Aline Cordeiro Campos de; Silva, Raisa Cristina Teodoro da; Trindade, Osmar Reni; Coelho, Maria Clara; Ferrioli, Eduardo; Bendassolli, José Albertino

2018-06-07

The 13C-urea breath test is the main non-invasive test for the diagnosis of Helicobacter pylori infection. The availability of this test throughout the country is limited, mainly due to the difficulty in obtaining the labeled isotope from abroad. Recently, researchers from the Nuclear Energy Center in Agriculture at the University of São Paulo (CENA/USP) succeeded in synthesizing 13C-enriched urea for Helicobacter pylori diagnosis. The aim of the study was to compare the performance of the 13C-urea breath test using 13C-urea acquired abroad with that of a test using 13C-urea synthesized in Brazil. Sixty-four dyspeptic patients participated in the study (24 men and 40 women). Initially, the patients performed the 13C-urea breath test using the imported substrate (Euriso-Top, France). Seven to fourteen days later, all the patients repeated the test using the Brazilian substrate. The samples from both examinations were processed in an infrared isotope analyzer (IRIS, Wagner Analisen Technik, Germany), and all delta over baseline (DOB) [%] values above four were considered positive results. Twenty-seven patients (42%) exhibited negative results for Helicobacter pylori infection, and thirty-seven patients (58%) exhibited positive results when tested using the foreign substrate (gold standard). There was a 100% concordance regarding the presence or absence of infection when the gold standard results were compared with those obtained using the Brazilian substrate. Similar performance in the diagnosis of Helicobacter pylori infection was demonstrated when using the 13C-urea breath test with the Brazilian 13C-urea substrate and the test with the substrate produced abroad. This validation represents an important step toward increasing the availability of the 13C-urea breath test throughout the country, which will have a positive influence on the management of Helicobacter pylori infection.

Breath biomarkers in toxicology.

PubMed

Pleil, Joachim D

2016-11-01

Exhaled breath has joined blood and urine as a valuable resource for sampling and analyzing biomarkers in human media for assessing exposure, uptake metabolism, and elimination of toxic chemicals. This article focuses current use of exhaled gas, aerosols, and vapor in human breath, the methods for collection, and ultimately the use of the resulting data. Some advantages of breath are the noninvasive and self-administered nature of collection, the essentially inexhaustible supply, and that breath sampling does not produce potentially infectious waste such as needles, wipes, bandages, and glassware. In contrast to blood and urine, breath samples can be collected on demand in rapid succession and so allow toxicokinetic observations of uptake and elimination in any time frame. Furthermore, new technologies now allow capturing condensed breath vapor directly, or just the aerosol fraction alone, to gain access to inorganic species, lung pH, proteins and protein fragments, cellular DNA, and whole microorganisms from the pulmonary microbiome. Future applications are discussed, especially the use of isotopically labeled probes, non-targeted (discovery) analysis, cellular level toxicity testing, and ultimately assessing "crowd breath" of groups of people and the relation to dose of airborne and other environmental chemicals at the population level.

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... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION CONTROL OF ALCOHOL AND DRUG USE Post-Accident Toxicological Testing § 219.206 FRA access to breath test results. Documentation of breath test results must be made available...

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... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION CONTROL OF ALCOHOL AND DRUG USE Post-Accident Toxicological Testing § 219.206 FRA access to breath test results. Documentation of breath test results must be made available...

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... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION CONTROL OF ALCOHOL AND DRUG USE Post-Accident Toxicological Testing § 219.206 FRA access to breath test results. Documentation of breath test results must be made available...

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... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION CONTROL OF ALCOHOL AND DRUG USE Post-Accident Toxicological Testing § 219.206 FRA access to breath test results. Documentation of breath test results must be made available...

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... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION CONTROL OF ALCOHOL AND DRUG USE Post-Accident Toxicological Testing § 219.206 FRA access to breath test results. Documentation of breath test results must be made available...

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

PubMed

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

2002-03-01

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

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

Data Mining Techniques Applied to Hydrogen Lactose Breath Test.

PubMed

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

2017-01-01

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

Outcome of breath tests in adult patients with suspected small intestinal bacterial overgrowth

PubMed Central

Mattsson, Johanna; Minaya, Maria Teresa; Monegro, Milka; Lebwohl, Benjamin; Lewis, Suzanne K.; Green, Peter HR; Stenberg, Reidun

2017-01-01

Aim: The aim was to investigate breath test outcomes in patients with suspected SIBO and indicative symptoms of SIBO, diagnosed by breath testing. Background: Breath testing is used to detect small intestinal bacterial overgrowth (SIBO) by measuring hydrogen and methane produced by intestinal bacteria. Methods: This retrospective cross sectional study included 311 patients with gastrointestinal symptoms who underwent the breath test for evaluation of SIBO at Celiac Disease Center at Columbia University, New York, in 2014-2015. The patients were divided into two groups based on the physician’s choice: lactulose breath test group (72%) and glucose breath test group (28%). Among them, 38% had a history of celiac disease or non-celiac gluten sensitivity. Results: In total, 46% had a positive breath test: 18% were positive for methane, 24 % positive for hydrogen and 4% positive for both gases (p=0.014). Also, 50% had a positive lactulose breath result and 37% had a positive glucose breath result (p=0.036). The most common symptom for performing the breath test was bloating and the only clinical symptom that significantly showed a positive glucose breath test was increased gas (p=0.028). Conclusion: Lactulose breath test was more often positive than glucose breath test. Positivity for hydrogen was more common than methane. Bloating was the most frequently perceived symptom of the patients undergoing the breath test but the only statistically significant clinical symptom for a positive glucose breath test was increased gas. Furthermore, the results showed that there was no significant association between positive breath test result and gender, age, non-celiac gluten sensitivity or celiac disease. PMID:29118931

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...

42 CFR 84.88 - Breathing bag test.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 42 Public Health 1 2012-10-01 2012-10-01 false Breathing bag test. 84.88 Section 84.88 Public 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...

42 CFR 84.88 - Breathing bag test.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 42 Public Health 1 2013-10-01 2013-10-01 false Breathing bag test. 84.88 Section 84.88 Public 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...

42 CFR 84.88 - Breathing bag test.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 42 Public Health 1 2011-10-01 2011-10-01 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...

Breathing simulator of workers for respirator performance test

PubMed Central

YUASA, Hisashi; KUMITA, Mikio; HONDA, Takeshi; KIMURA, Kazushi; NOZAKI, Kosuke; EMI, Hitoshi; OTANI, Yoshio

2014-01-01

Breathing machines are widely used to evaluate respirator performance but they are capable of generating only limited air flow patterns, such as, sine, triangular and square waves. In order to evaluate the respirator performance in practical use, it is desirable to test the respirator using the actual breathing patterns of wearers. However, it has been a difficult task for a breathing machine to generate such complicated flow patterns, since the human respiratory volume changes depending on the human activities and workload. In this study, we have developed an electromechanical breathing simulator and a respiration sampling device to record and reproduce worker’s respiration. It is capable of generating various flow patterns by inputting breathing pattern signals recorded by a computer, as well as the fixed air flow patterns. The device is equipped with a self-control program to compensate the difference in inhalation and exhalation volume and the measurement errors on the breathing flow rate. The system was successfully applied to record the breathing patterns of workers engaging in welding and reproduced the breathing patterns. PMID:25382381

Breathing simulator of workers for respirator performance test.

PubMed

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

2015-01-01

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

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 ...

[Application of the breath hydrogen test in gastroenterology].

PubMed

Loranskaia, I D; Panina, N A; Zheltakova, O V

2006-01-01

The diagnostic capacities of the breath hydrogen test in gastroenterology are discussed in the article. The authors describe the results of their own research--determination of the intestinal bacterial contamination in patients with chronic biliary pancreatitis with the help of the Micro H2 breath hydrogen analyzer.

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

PubMed

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

2003-04-01

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

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Veldhuyzen van Zanten, S.J.; Tytgat, K.M.; Hollingsworth, J.

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%, positivemore » 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.« less

The Wagner-Nelson method can generate an accurate gastric emptying flow curve from CO2 data obtained by a 13C-labeled substrate breath test.

PubMed

Sanaka, Masaki; Yamamoto, Takatsugu; Ishii, Tarou; Kuyama, Yasushi

2004-01-01

In pharmacokinetics, the Wagner-Nelson (W-N) method can accurately estimate the rate of drug absorption from its urinary elimination rate. A stable isotope (13C) breath test attempts to estimate the rate of absorption of 13C, as an index of gastric emptying rate, from the rate of pulmonary elimination of 13CO2. The time-gastric emptying curve determined by the breath test is quite different from that determined by scintigraphy or ultrasonography. In this report, we have shown that the W-N method can adjust the difference. The W-N equation to estimate gastric emptying from breath data is as follows: the fractional cumulative amount of gastric contents emptied by time t = Abreath (t)/Abreath (infinity) + (1/0.65).d[Abreath (t)/Abreath (infinity) ]/dt, where Abreath (t) = the cumulative recovery of 13CO2 in breath by time t and Abreath ( infinity ) = the ultimate cumulative 13CO2 recovery. The emptying flow curve generated by ultrasonography was compared with that generated by the W-N method-adjusted breath test in 6 volunteers. The emptying curves by the W-N method were almost identical to those by ultrasound. The W-N method can generate an accurate emptying flow curve from 13CO2 data, and it can adjust the difference between ultrasonography and the breath test. Copyright 2004 S. Karger AG, Basel

[*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.

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.

Effects of homeopathic mother tinctures on breath alcohol testing.

PubMed

Boatto, Gianpiero; Trignano, Claudia; Burrai, Lucia; Spanu, Andrea; Nieddu, Maria

2015-01-01

In some countries, it is illegal to drive with any detectable amount of alcohol in blood; in others, the legal limit is 0.5 g/L or lower. Recently, some defendants charged with driving under the influence of alcohol and have claimed that positive breath alcohol test results were due to the ingestion of homeopathic mother tinctures. These preparations are obtained by maceration, digestion, infusion, or decoction of herbal material in hydroalcoholic solvent. A series of tests were conducted to evaluate the alcoholic content of three homeopathic mother tinctures and their ability to produce inaccurate breath alcohol results. Nine of 30 subjects gave positive results (0.11-0.82 g/L) when tests were taken within 1 min after drinking mother tincture. All tests taken at least 15 min after the mother tincture consumption and resulted in alcohol-free readings. An observation period of 15-20 min prior to breath alcohol testing eliminates the possibility of false-positive results. © 2014 American Academy of Forensic Sciences.

Clinical significance of the glucose breath test in patients with inflammatory bowel disease.

PubMed

Lee, Ji Min; Lee, Kang-Moon; Chung, Yoon Yung; Lee, Yang Woon; Kim, Dae Bum; Sung, Hea Jung; Chung, Woo Chul; Paik, Chang-Nyol

2015-06-01

Small intestinal bacterial overgrowth which has recently been diagnosed with the glucose breath test is characterized by excessive colonic bacteria in the small bowel, and results in gastrointestinal symptoms that mimic symptoms of inflammatory bowel disease. This study aimed to estimate the positivity of the glucose breath test and investigate its clinical role in inflammatory bowel disease. Patients aged > 18 years with inflammatory bowel disease were enrolled. All patients completed symptom questionnaires. Fecal calprotectin level was measured to evaluate the disease activity. Thirty historical healthy controls were used to determine normal glucose breath test values. A total of 107 patients, 64 with ulcerative colitis and 43 with Crohn's disease, were included. Twenty-two patients (20.6%) were positive for the glucose breath test (30.2%, Crohn's disease; 14.1%, ulcerative colitis). Positive rate of the glucose breath test was significantly higher in patients with Crohn's disease than in healthy controls (30.2% vs 6.7%, P=0.014). Bloating, flatus, and satiety were higher in glucose breath test-positive patients than glucose breath test-negative patients (P=0.021, 0.014, and 0.049, respectively). The positivity was not correlated with the fecal calprotectin level. The positive rate of the glucose breath test was higher in patients with inflammatory bowel disease, especially Crohn's disease than in healthy controls; gastrointestinal symptoms of patients with inflammatory bowel disease were correlated with this positivity. Glucose breath test can be used to manage intestinal symptoms of patients with inflammatory bowel disease. © 2015 Journal of Gastroenterology and Hepatology Foundation and Wiley Publishing Asia Pty Ltd.

[Examination of gastric emptying rate by means of 13C-octanoic acid breath test. Methods of the test for adults and results of the investigation of healthy volunteers].

PubMed

Bures, J; Kopácová, M; Vorísek, V; Bukac, J; Neumann, D; Rejchrt, S; Pozler, O; Douda, T; Zivný, P; Palicka, V

2005-01-01

13C-octanoic acid breath test (13C-OABT) is a simple, safe and non-invasive technique for measuring gastric emptying. However, the method has not been standardized yet. Aim of the study was to work up, introduce and evaluate our own method of the 13C-OABT for adults. Ten healthy volunteers entered the study (5 men, 5 women, mean age 32 years, 50 % Helicobacter pylori positive). Standard test meals (with 100 mg 13C-sodium octanoate) were used three times within 3 weeks. The same solid meal (1,178 kJ) for Tests 1 and 2 contained scrambled egg (+ 3 g oil), white bread (40 g), butter (10 g) and distilled water (200 ml). Semi-solid meal (1,020 kJ) for Test 3 contained milk pudding (200 g) and distilled water (200 ml). Duplicate breath samples were obtained before and every 15 minutes after eating the test meal during 255 minutes. Altogether 1,080 breath samples were analysed twice (isotope ratio mass spectrometry, AP2003 Analytical Precision, UK). To assess the half-life of elimination (t1/2 E), we modelled the process of elimination with the incomplete gamma-function, which has a convenient form for the empiric plotting of breath test data. Mean t1/2E was 136+/-10 minutes (Test 1), 134+/-14 (Test 2) and 123+/-16 minutes (Test 3). Clinical reproducibility of 13C-OABT in particular persons was 98.2% (18 breath samples series), 90.8 % (15 samples) and 87.1% (9 breath samples series). There was a significant correlation between Test 1 and Test 2 results (r=0.887, p<0.0001). Mean difference of duplicate breath sample analysis was 1.460 % (in 540 pairs), mean baseline one-day analysis difference was 0.0982 (99.9274% accuracy). In healthy volunteers, normal range of t1/2E is 110-160 minutes for solids and 91-155 minutes for semisolid test meal. Using our own computed mean time of intermediate metabolism of 13C-octanoic acid (76.5+/-7.5 minutes), gastric emptying half-time is 33.5-83.5 minutes for solids and 14.5-78.5 minutes for semisolid test meal in healthy volunteers. The

A metabolic simulator for unmanned testing of breathing apparatuses in hyperbaric conditions.

PubMed

Frånberg, Oskar; Loncar, Mario; Larsson, Åke; Ornhagen, Hans; Gennser, Mikael

2014-11-01

A major part of testing of rebreather apparatuses for underwater diving focuses on the oxygen dosage system. A metabolic simulator for testing breathing apparatuses was built and evaluated. Oxygen consumption was achieved through catalytic combustion of propene. With an admixture of carbon dioxide in the propene fuel, the system allowed the respiratory exchange ratio to be set freely within human variability and also made it possible to increase test pressures above the condensation pressure of propene. The system was tested by breathing ambient air in a pressure chamber with oxygen uptake (Vo₂) ranging from 1-4 L · min(-1), tidal volume (VT) from 1-3 L, breathing frequency (f) of 20 and 25 breaths/min, and chamber pressures from 100 to 670 kPa. The measured end-tidal oxygen concentration (Fo₂) was compared to calculated end-tidal Fo₂. The largest average difference in end-tidal Fo₂during atmospheric pressure conditions was 0.63%-points with a 0.28%-point average difference during the whole test. During hyperbaric conditions with pressures ranging from 100 to 670 kPa, the largest average difference in Fo₂was 1.68%-points seen during compression from 100 kPa to 400 kPa and the average difference in Fo₂during the whole test was 0.29%-points. In combination with a breathing simulator simulating tidal breathing, the system can be used for dynamic continuous testing of breathing equipment with changes in VT, f, Vo2, and pressure.

Breath analysis with broadly tunable quantum cascade lasers.

PubMed

Wörle, Katharina; Seichter, Felicia; Wilk, Andreas; Armacost, Chris; Day, Tim; Godejohann, Matthias; Wachter, Ulrich; Vogt, Josef; Radermacher, Peter; Mizaikoff, Boris

2013-03-05

With the availability of broadly tunable external cavity quantum cascade lasers (EC-QCLs), particularly bright mid-infrared (MIR; 3-20 μm) light sources are available offering high spectral brightness along with an analytically relevant spectral tuning range of >2 μm. Accurate isotope ratio determination of (12)CO2 and (13)CO2 in exhaled breath is of critical importance in the field of breath analysis, which may be addressed via measurements in the MIR spectral regime. Here, we combine for the first time an EC-QCL tunable across the (12)CO2/(13)CO2 spectral band with a miniaturized hollow waveguide gas cell for quantitatively determining the (12)CO2/(13)CO2 ratio within the exhaled breath of mice. Due to partially overlapping spectral features, these studies are augmented by appropriate multivariate data evaluation and calibration techniques based on partial least-squares regression along with optimized data preprocessing. Highly accurate determinations of the isotope ratio within breath samples collected from a mouse intensive care unit validated via hyphenated gas chromatography-mass spectrometry confirm the viability of IR-HWG-EC-QCL sensing techniques for isotope-selective exhaled breath analysis.

A quantitative evaluation of spurious results in the infrared spectroscopic measurement of CO2 isotope ratios

NASA Astrophysics Data System (ADS)

Mansfield, C. D.; Rutt, H. N.

2002-02-01

The possible generation of spurious results, arising from the application of infrared spectroscopic techniques to the measurement of carbon isotope ratios in breath, due to coincident absorption bands has been re-examined. An earlier investigation, which approached the problem qualitatively, fulfilled its aspirations in providing an unambiguous assurance that 13C16O2/12C16O2 ratios can be confidently measured for isotopic breath tests using instruments based on infrared absorption. Although this conclusion still stands, subsequent quantitative investigation has revealed an important exception that necessitates a strict adherence to sample collection protocol. The results show that concentrations and decay rates of the coincident breath trace compounds acetonitrile and carbon monoxide, found in the breath sample of a heavy smoker, can produce spurious results. Hence, findings from this investigation justify the concern that breath trace compounds present a risk to the accurate measurement of carbon isotope ratios in breath when using broadband, non-dispersive, ground state absorption infrared spectroscopy. It provides recommendations on the length of smoking abstention required to avoid generation of spurious results and also reaffirms, through quantitative argument, the validity of using infrared absorption spectroscopy to measure CO2 isotope ratios in breath.

Limited electromagnetic interference testing of evidential breath testers

DOT National Transportation Integrated Search

1983-05-06

This report summarizes a limited test program conducted to determine the susceptibility of evidential breath testers (EBTs) to radio frequency interference (RFI). Several comprehensive test protocols were prepared based on procedures developed by the...

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

Code of Federal Regulations, 2010 CFR

2010-10-01

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

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

Code of Federal Regulations, 2011 CFR

2011-10-01

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

Results of the first semi-annual qualification testing of devices to measure breath alcohol

DOT National Transportation Integrated Search

1975-01-01

Eight evidential breath testers were performance tested according to the Standard for Devices to Measure Breath Alcohol Federal Register, Vol 38, No. 212, November 5, 1973. In addition, a prototype breath tester not commercially available was tested....

Follow-up of coeliac disease with the novel one-hour 13C-sorbitol breath test versus the H2-sorbitol breath test.

PubMed

Tveito, Kari; Hetta, Anne Kristine; Askedal, Mia; Brunborg, Cathrine; Sandvik, Leiv; Løberg, Else Marit; Skar, Viggo

2011-07-01

We recently developed a (13)C-sorbitol breath test ((13)C-SBT) as an alternative to the H(2)-sorbitol breath test (H(2)-SBT) for coeliac disease. In this study we compared the diagnostic properties of the H(2)-SBT and the (13)C-SBT in follow-up of coeliac disease. Twenty-seven coeliac patients on a gluten-free diet (GFD) performed the breath tests. All had been tested before treatment in the initial study of the (13)C-SBT, in which 39 untreated coeliac patients, 40 patient controls, and 26 healthy volunteers participated. Five gram sorbitol and 100 mg (13)C-sorbitol were dissolved in 250 ml tap water and given orally. H(2), CH(4) and (13)CO(2) were measured in end-expiratory breath samples every 30 min for 4 h. Increased H(2) concentration ≥20 ppm from basal values was used as cut-off for the H(2)-SBT. Sixty minutes values were used as diagnostic index in the (13)C-SBT. (13)CO(2) levels at 60 min increased in 20/26 treated coeliac patients (77%) after GFD, but were significantly lower than in control groups. Out of 20 patients who had a positive H(2)-SBT before GFD, 12 had a negative H(2)-SBT after GFD. Peak H(2) concentrations were not correlated with (13)C-SBT results. The study confirms the sensitivity of a one-hour (13)C-SBT for small intestinal malabsorption. The (13)C-SBT has superior diagnostic properties compared with the H(2)-SBT in follow-up of coeliac disease.

Significance of hydrogen breath tests in children with suspected carbohydrate malabsorption

PubMed Central

2014-01-01

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

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

NASA Astrophysics Data System (ADS)

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

2015-04-01

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

Prediction of heart transplant rejection with a breath test for markers of oxidative stress.

PubMed

Phillips, Michael; Boehmer, John P; Cataneo, Renee N; Cheema, Taseer; Eisen, Howard J; Fallon, John T; Fisher, Peter E; Gass, Alan; Greenberg, Joel; Kobashigawa, Jon; Mancini, Donna; Rayburn, Barry; Zucker, Mark J

2004-12-15

The Heart Allograft Rejection: Detection with Breath Alkanes in Low Levels study evaluated a breath test for oxidative stress in heart transplant recipients, and we report here a mathematical model predicting the probability of grade 3 rejection. The breath test divided the heart transplant recipients into 3 groups: positive for grade 3 rejection, negative for grade 3 rejection, and intermediate. The test was 100% sensitive for grade 3 heart transplant rejection when the p value was >/=0.98, and 100% specific when the p value was breath test determined the probability of grade 3 rejection and the predictive value of the result.

[Breath tests in children with suspected lactose intolerance].

PubMed

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

2015-01-01

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

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 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Toxicology Test Systems § 862...

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 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Toxicology Test Systems § 862...

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 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Toxicology Test Systems § 862...

Prevalence of abnormal lactose breath hydrogen tests in children with functional abdominal pain.

PubMed

Garg, Neha; Basu, Srikanta; Singh, Preeti; Kumar, Ruchika; Sharma, Lokesh; Kumar, Praveen

2017-05-01

The study was undertaken to determine the prevalence of abnormal lactose breath hydrogen test in children with non-organic chronic abdominal pain. Children with chronic abdominal pain were examined and investigated for organic causes. All children without a known organic cause underwent lactose and glucose breath hydrogen test. After a standard dose of 2 g/kg of lactose to a maximum of 50 g, hydrogen in breath was measured at 15 min intervals for 3 h. A rise of 20 ppm above baseline was considered suggestive of lactose malabsorption. Of 108 children screened, organic causes were found in 46 children. Sixty-two patients without any organic cause underwent hydrogen breath test. Lactose hydrogen breath test (HBT) was positive in 36 of 62 (58%), while 11 (17%) had positive HBT with glucose suggestive of small intestinal bacterial overgrowth (SIBO). Twenty out of 34 (59%) improved on lactose free diet while 8 out of 11 (72%) children of SIBO improved on antibiotics. Lactose malabsorption was seen in 58% of children with non-organic chronic abdominal pain.

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.

BreathDx - molecular analysis of exhaled breath as a diagnostic test for ventilator-associated pneumonia: protocol for a European multicentre observational study.

PubMed

van Oort, Pouline M P; Nijsen, Tamara; Weda, Hans; Knobel, Hugo; Dark, Paul; Felton, Timothy; Rattray, Nicholas J W; Lawal, Oluwasola; Ahmed, Waqar; Portsmouth, Craig; Sterk, Peter J; Schultz, Marcus J; Zakharkina, Tetyana; Artigas, Antonio; Povoa, Pedro; Martin-Loeches, Ignacio; Fowler, Stephen J; Bos, Lieuwe D J

2017-01-03

The diagnosis of ventilator-associated pneumonia (VAP) remains time-consuming and costly, the clinical tools lack specificity and a bedside test to exclude infection in suspected patients is unavailable. Breath contains hundreds to thousands of volatile organic compounds (VOCs) that result from host and microbial metabolism as well as the environment. The present study aims to use breath VOC analysis to develop a model that can discriminate between patients who have positive cultures and who have negative cultures with a high sensitivity. The Molecular Analysis of Exhaled Breath as Diagnostic Test for Ventilator-Associated Pneumonia (BreathDx) study is a multicentre observational study. Breath and bronchial lavage samples will be collected from 100 and 53 intubated and ventilated patients suspected of VAP. Breath will be analysed using Thermal Desorption - Gas Chromatography - Mass Spectrometry (TD-GC-MS). The primary endpoint is the accuracy of cross-validated prediction for positive respiratory cultures in patients that are suspected of VAP, with a sensitivity of at least 99% (high negative predictive value). To our knowledge, BreathDx is the first study powered to investigate whether molecular analysis of breath can be used to classify suspected VAP patients with and without positive microbiological cultures with 99% sensitivity. UKCRN ID number 19086, registered May 2015; as well as registration at www.trialregister.nl under the acronym 'BreathDx' with trial ID number NTR 6114 (retrospectively registered on 28 October 2016).

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

PubMed

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

2015-04-01

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

13C-Mixed Triglyceride Breath Test and Fecal Elastase as an Indirect Pancreatic Function Test in Cystic Fibrosis Infants.

PubMed

Kent, Dorothea Stark; Remer, Thomas; Blumenthal, Caron; Hunt, Sharon; Simonds, Sharon; Egert, Sarah; Gaskin, Kevin J

2018-05-01

The 'gold standard' test for the indirect determination of pancreatic function status in infants with cystic fibrosis (CF), the 72-hour fecal fat excretion test, is likely to become obsolete in the near future. Alternative indirect pancreatic function tests with sufficient sensitivity and specificity to determine pancreatic phenotype need further evaluation in CF infants. Evaluation of the clinical utility of both the noninvasive, nonradioactive C-mixed triglyceride (MTG) breath test and fecal elastase-1 (FE1) in comparison with the 72-hour fecal fat assessment in infants with CF. C-MTG breath test and the monoclonal and polyclonal FE1 assessment in stool was compared with the 72-hour fecal fat assessment in 24 infants with CF. Oral pancreatic enzyme substitution (PERT; if already commenced) was stopped before the tests. Sensitivity rates between 82% and 100% for CF patients with pancreatic insufficiency assessed by both the C-MTG breath test and the FE1 tests proved to be high and promising. The C-MTG breath test (31%-38%) as well as both FE1 tests assessed by the monoclonal (46%-54%) and the polyclonal (45%) ELISA kits, however, showed unacceptably low-sensitivity rates for the detection of pancreatic-sufficient CF patients in the present study. The C-MTG breath test with nondispersive infrared spectroscopy (NDIRS) technique, as well as both FE1 tests, are not alternatives to the fecal fat balance test for the evaluation of pancreatic function in CF infants during the first year of life.

[Analysis of breath hydrogen (H2) in diagnosis of gastrointestinal function: validation of a pocket breath H2 test analyzer].

PubMed

Braden, B; Braden, C P; Klutz, M; Lembcke, B

1993-04-01

Breath hydrogen (H2) analysis, as used in gastroenterologic function tests, requires a stationary analysis system equipped with a gaschromatograph or an electrochemical sensor cell. Now a portable breath H2-analyzer has been miniaturized to pocket size (104 mm x 62 mm x 29 mm). The application of this device in clinical practice has been assessed in comparison to the standard GMI-exhaled monitor. The pocket analyzer showed a linear response to standards with H2-concentrations ranging from 0-100 ppm (n = 7), which was not different from the GMI-apparatus. The correlation of both methods during clinical application (lactose tolerance tests, mouth-to-coecum transit time determined with lactulose) was excellent (Y = 1.08 X + 0.96; r = 0.959). Using the new device, both, analysis (3 s vs. 90 s) and the reset-time (43 s vs. 140 s) were shorter whereas calibration was more feasible with the GMI-apparatus. It is concluded, that the considerably cheaper pocket-sized breath H2-analyzer is as precise and sensitive as the GMI-exhaled monitor, and thus presents a valid alternative for H2-breath tests.

Breath test refusals

DOT National Transportation Integrated Search

2007-11-01

The National Highway Traffic Safety Administration has found that the percentage of people who refuse to provide breath samples when arrested for Driving While Intoxicated (DWI) varies considerably across States, and this creates a concern in the cri...

21 CFR 862.3080 - Breath nitric oxide test system.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Breath nitric oxide test system. 862.3080 Section 862.3080 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Toxicology Test...

21 CFR 862.3080 - Breath nitric oxide test system.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Breath nitric oxide test system. 862.3080 Section 862.3080 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Toxicology Test...

21 CFR 862.3080 - Breath nitric oxide test system.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Breath nitric oxide test system. 862.3080 Section 862.3080 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Toxicology Test...

21 CFR 862.3080 - Breath nitric oxide test system.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Breath nitric oxide test system. 862.3080 Section 862.3080 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Toxicology Test...

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.

Breath test refusals and DWI prosecution : traffic tech.

DOT National Transportation Integrated Search

2012-08-01

There are typically about 1.4 million DWI (driving while : impaired) arrests each year in the United States. An officers : request to a driver for a breath (or blood, or urine) test is an : important part of the arrest process. The percentage of d...

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) The...

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) The...

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

Code of Federal Regulations, 2013 CFR

2013-01-01

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

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

Code of Federal Regulations, 2012 CFR

2012-01-01

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

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

Code of Federal Regulations, 2014 CFR

2014-01-01

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

[Detection of Helicobacter pylori by culture and the 13C-urea breath test using an automated breath 13C analyzer].

PubMed

Yamamoto, Y; Kouda, M; Abe, K; Sakurabayashi, S; Sezai, S; Hirano, M; Oka, H

1995-11-01

Up to now, the diagnosis of H. pylori infection has been made by the breath test using 13C-urea. In this study, 13C-urea breath samples were tested in 34 patients (peptic ulcer scar 17, chronic gastritis 17 cases) with an automated breath 13C analyzer (ABCA. Europa Scientific, Crewe, UK) and compared with the results of endoscopical diagnosis for H. pylori infection. Endoscopic and 13C-urea breath test (13C-UBT) were performed before eradicative medication. We described a modified protocol for the growth grade of H. pylori colonies in microbiology (H. pylori score), and for the delta 13C area under curve (AUC; permil*hr) obtained from each sample of expired breath. There was a significant correlation between delta 13C-AUC and the delta 13C level of each sample, but the correlation coefficient obtained at 10min (R2 = 0.582) was lower than that obtained at the other four time points (20min; 0.891, 30min; 0.949, 40min; 0.946, 50min; 0.946, 60min; 0.820). The delta 13C-AUC well correlated with H. pylori score (p < 0.01), none of 26 H. pylori positive patients detected by culture was 13C-UBT negative (delta 13C-AUC < 8.2 permil*hr in mean + 2SD of H. pylori negative group). In conclusion, 13C-UBT using ABCA has high sensitivity and specificity, and it provides a non-invasive method for the detection of H. pylori urease activity.

Isotope-selective sensor for medical diagnostics based on PAS

NASA Astrophysics Data System (ADS)

Wolff, M.; Groninga, H. G.; Harde, H.

2005-06-01

Development of new optical sensor technologies has a major impact on the progression of diagnostic methods. Of the permanently increasing number of non-invasive 13C-breath tests, the Urea Breath Test for detection of Helicobacter pylori is the most prominent. However, many recent developments go beyond gastroenterological applications. We present a new detection scheme for breath analysis that employs an especially compact and simple set-up based on Photoacoustic Spectroscopy. Using a wavelength-modulated DFB-diode laser and taking advantage of acoustical resonances of the sample cell, we performed very sensitive isotope-selective measurements on CO2. Detection limits for 13CO2 of a few ppm and for the variation of the 13CO2 concentration of approximately 1% were achieved.

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.

(13)C breath tests in personalized medicine: fiction or reality?

PubMed

Modak, Anil S

2009-11-01

The concept of personalized medicine is gathering momentum as various biomarkers are being discovered and developed to lead to genotype and phenotype diagnostic tests, which will enable physicians to individualize therapy. Noninvasive, rapid (13)C breath tests have the potential to serve as clinically significant diagnostic tools, especially for evaluating the enzyme activity of polymorphic enzymes. This would enable physicians to rapidly identify responders/nonresponders to various drugs primarily metabolized by these enzymes prior to initiation of therapy. With the information on enzyme activity, the physician can prescribe the right drug, at the right dose, at the right time, to the right individual, for the right clinical outcome. However, the promise of the era of personalized medicine, including the novel (13)C breath tests, will have to overcome several regulatory, business and financial hurdles for diagnostic tests to become part of routine mainstream clinical practice over the next decade.

[Reliability study on the infrared spectrometry for measuring the delta over baseline for breath 13C].

PubMed

Wang, Min; Wang, Zhiling; Gou, Lingyan; Zhang, Yuhui; Yang, Xiaoguang; Sha, Lei; Li, Min

2013-03-01

To assess the validity and reliability of the infrared spectrometry for measuring the delta over baseline for breath 13C. Twenty-four healthy adults were selected, including twelve males and twelve females. 13C-Leucine was used as tracer in stable isotope metabolic experiments. One baseline breath was collected before the tracer protocol began. Other breath samples were collected at 60, 120, 180, 195, 210, 225, 240, 255, 270 and 300 min post-tracer challenge. The delta over baseline for breath 13C was measured by the infrared spectrometry and Heliview 13C breath analyzer. No significant differences were found between the infrared spectrometry and Heliview 13C breath analyzer in measuring the delta over baseline for breath 13C. The F value and p value of two-way ANOVA were 0.29 and 0.5874 respectively. The t and p value of consistency test were 0.48 and 0.6346 respectively. The 13C infrared spectrometry can reliably measure the delta over baseline for breath 13C.

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.

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

PubMed

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

2012-03-01

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

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

Can Handling E85 Motor Fuel Cause Positive Breath Alcohol Test Results?

PubMed Central

Ran, Ran; Mullins, Michael E.

2013-01-01

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

Breath Test Refusals and Their Effect on DWI Prosecution

DOT National Transportation Integrated Search

2012-07-01

This report describes the design and results of a project aimed at estimating the rate that drivers : refuse to submit to a legally-requested breath alcohol concentration test, and the effect of such : refusals on the prosecution of DWI cases. The st...

A better state-of-mind: deep breathing reduces state anxiety and enhances test performance through regulating test cognitions in children.

PubMed

Khng, Kiat Hui

2017-11-01

A pre-test/post-test, intervention-versus-control experimental design was used to examine the effects, mechanisms and moderators of deep breathing on state anxiety and test performance in 122 Primary 5 students. Taking deep breaths before a timed math test significantly reduced self-reported feelings of anxiety and improved test performance. There was a statistical trend towards greater effectiveness in reducing state anxiety for boys compared to girls, and in enhancing test performance for students with higher autonomic reactivity in test-like situations. The latter moderation was significant when comparing high-versus-low autonomic reactivity groups. Mediation analyses suggest that deep breathing reduces state anxiety in test-like situations, creating a better state-of-mind by enhancing the regulation of adaptive-maladaptive thoughts during the test, allowing for better performance. The quick and simple technique can be easily learnt and effectively applied by most children to immediately alleviate some of the adverse effects of test anxiety on psychological well-being and academic performance.

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.

Quantification of Helicobacter pylori infection in gastritis and ulcer disease using a simple and rapid carbon-14-urea breath test

DOE Office of Scientific and Technical Information (OSTI.GOV)

Debongnie, J.C.; Pauwels, S.; Raat, A.

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 wasmore » 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.« less

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

PubMed Central

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

2014-01-01

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

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

Evaluation of 13CO2 breath tests for the detection of fructose malabsorption.

PubMed

Hoekstra, J H; van den Aker, J H; Kneepkens, C M; Stellaard, F; Geypens, B; Ghoos, Y F

1996-03-01

Breath hydrogen (H2) studies have made clear that small intestinal absorption of fructose is limited, especially in toddlers. Malabsorption of fructose may be a cause of recurrent abdominal pain and chronic nonspecific diarrhea (toddler's diarrhea). Fructose absorption is facilitated by equimolar doses of glucose and, as we have found, amino acids (especially L-alanine); the mechanism underlying this effect remains unclear. To study fructose absorption in a more direct way, we combined breath H2 studies with breath 13CO2 studies. Gastric emptying was studied by using L-glycine-1-13C in 4 children from 12.1 to 16.0 years of age. After 25 gm of fructose and 27.5 gm of glucose, when given together, gastric emptying was significantly (p<0.05) slower than with either sugar alone. In a second series of experiments, 5 children from 12.0 to 15.9 years of age were tested with 25 gm of fructose, alone and with equimolar doses of glucose and L-alanine, and 4 younger children from 3.1 to 6.1 years of age were tested with 2 gm/kg (max 37.5 gm) fructose, alone or with an equimolar dose of L-alanine. All fructose solutions were enriched with 15 mg of D-fructose-13C-6. In all 9 children, fructose was malabsorbed as judged by breath H2 increases > or = 20 ppm, and the addition of glucose or L-alanine resulted in significantly lower breath H2 increases (p < or = 0.005 for glucose, p < or = 0.001 for alanine). In contrast, the addition of alanine or glucose did not change the pattern of breath 13CO2 excretion in the 5 older children, whereas in the 4 younger children (with relatively higher doses), L-alanine addition resulted in significantly lower increases in breath 13CO2. In the latter group, for each time point, breath H2 and 13CO2 concentrations after fructose were compared with those after fructose plus L-alanine; in 20 out of 24 points, both H2 and 13CO2 were higher after fructose. These results suggest that 13CO2 not only originated from the oxidation of absorbed substrate

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

PubMed

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

2016-11-28

Respiratory problems are common in horses, and are often diagnosed as a cause of poor athletic performance. Reliable, accurate and sensitive spirometric tests of airway function in resting horses would assist with the diagnosis of limitations to breathing and facilitate investigations of the effects of various treatments on breathing capacity. The evaluation of respiratory function in horses is challenging and suitable procedures are not widely available to equine practitioners. The determination of relative flow or flow-time measures is used in paediatric patients where compliance may limit conventional pulmonary function techniques. The aim of the current study was to characterise absolute and relative indices of respiratory function in healthy horses during eupnoea (tidal breathing) and carbon dioxide (CO 2 )-induced hyperpnoea (rebreathing) using a modified mask pneumotrachographic technique well suited to equine practice, and to evaluate the reliability of this technique over three consecutive days. Coefficients of variation, intra-class correlations, mean differences and 95% confidence intervals across all days of testing were established for each parameter. The technique provided absolute measures of respiratory function (respiratory rate, tidal volume, peak inspiratory and expiratory flows, time to peak flow) consistent with previous studies and there was no significant effect of day on any measure of respiratory function. Variability of measurements was decreased during hyperpnea caused by rebreathing CO 2 , but a number of relative flow-time variables demonstrated good agreement during eupnoeic respiration. The technique was well tolerated by horses and study findings suggest the technique is suitable for evaluation of respiratory function in horses. The use of relative flow-time variables provided reproducible (consistent) results, suggesting the technique may be of use for repeated measures studies in horses during tidal breathing or rebreathing.

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.

42 CFR 84.152 - Breathing tube test; minimum requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

...: (i) Be employed on Type C supplied-air respirators of the demand and pressure-demand class; and (ii... SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Supplied-Air Respirators § 84.152 Breathing tube test; minimum requirements. (a)(1) Type A and Type B supplied-air...

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

PubMed

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

2016-05-01

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

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.

The Effect of Alcohol-Based Hand Sanitizer Vapors on Evidential Breath Alcohol Test Results.

PubMed

Strawsine, Ellen; Lutmer, Brian

2017-11-16

This study was undertaken to determine if the application of alcohol-based hand sanitizers (ABHSs) to the hands of a breath test operator will affect the results obtained on evidential breath alcohol instruments (EBTs). This study obtained breath samples on three different EBTs immediately after application of either gel or foam ABHS to the operator's hands. A small, but significant, number of initial analyses (13 of 130, 10%) resulted in positive breath alcohol concentrations, while 41 samples (31.5%) resulted in a status code. These status codes were caused by ethanol vapors either in the room air or their inhalation by the subject, thereby causing a mouth alcohol effect. Replicate subject samples did not yield any consecutive positive numeric results. As ABHS application can cause a transitory mouth alcohol effect via inhalation of ABHS vapors, EBT operators should forego the use of ABHS in the 15 min preceding subject testing. © 2017 American Academy of Forensic Sciences.

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

46 CFR 197.450 - Breathing gas tests.

Code of Federal Regulations, 2010 CFR

2010-10-01

... taken at the connection point to the distribution system— (1) Every 6 months; and (2) After every repair or modification. (b) Purchased supplies of breathing mixtures supplied to a diver are checked before... commencement of diving operations, at the umbilical or underwater breathing apparatus connection point for the...

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

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.

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.

13C-methacetin and 13C-galactose breath tests can assess restricted liver function even in early stages of primary biliary cirrhosis.

PubMed

Holtmeier, Julia; Leuschner, Maria; Schneider, Arne; Leuschner, Ulrich; Caspary, Wolfgang F; Braden, Barbara

2006-11-01

The 13C-methacetin breath test quantitatively evaluates cytochrome P450-dependent liver function. The 13C-galactose breath test non-invasively measures the galactose oxidation capacity of the liver. The aim of this study was to find out whether these breath tests are sensitive parameters also in non-cirrhotic patients with primary biliary cirrhosis. Nineteen patients with early-stage primary biliary cirrhosis (no cirrhotic alterations in the liver biopsy, Ludwig stage I-III) and 20 healthy controls underwent the 13C-methacetin and 13C-galactose breath tests. Patients with primary biliary cirrhosis metabolized less 13C-methacetin than controls (cumulative recovery within 30 min 7.5+/-2.4% versus 14.0+/-2.6%; p < 0.001). When a cut-off > 9.8% was used for the cumulative recovery after 30 min, the methacetin breath test reached 84.2% sensitivity and 95.0 specificity. In the 13C-galactose breath test, the percentage recovery at 60 min in patients was 3.1+/-1.3%/h, and 6.3+/-1.1%/h in controls (p < 0.001). Using a cut-off > 4.7%/h, the galactose breath test reached 89.5% sensitivity and 95.0 specificity. In non-cirrhotic, early-stage, primary biliary cirrhosis the 13C-methacetin breath test and the 13C-galactose breath test reliably indicate decreased liver function. The 13C-galactose breath test can also predict the histological score.

Aspiration tests in aqueous foam using a breathing simulator

DOE Office of Scientific and Technical Information (OSTI.GOV)

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 inmore » 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.« less

Application of LaserBreath-001 for breath acetone measurement in subjects with diabetes mellitus

NASA Astrophysics Data System (ADS)

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

2016-11-01

Breath acetone is a promising biomarker of diabetes mellitus. With an integrated standalone, on-site cavity ringdown breath acetone analyzer, LaserBreath-001, we tested breath samples from 23 type 1 diabetic (T1D) patients, 312 type 2 diabetic (T2D) patients, 52 healthy subjects. In the cross-sectional studies, the obtained breath acetone concentrations were higher in the diabetic subjects compared with those in the control group. No correlation between breath acetone and simultaneous BG was observed in the T1D, T2D, and healthy subjects. A moderate positive correlation between the mean individual breath acetone concentrations and the mean individual BG levels was observed in the 20 T1D patients without ketoacidosis. In a longitudinal study, the breath acetone concentrations in a T1D patient with ketoacidosis decreased significantly and remained stable during the 5-day hospitalization. The results from a relatively large number of subjects tested indicate that an elevated mean breath acetone concentration exists in diabetic patients in general. Although many physiological parameters affect breath acetone concentrations, fast (<1 min) and on site breath acetone measurement can be used for diabetic screening and management under a specifically controlled condition.

A specialized isotope mass spectrometer for noninvasive diagnostics of Helicobacter pylori infection in human beings

NASA Astrophysics Data System (ADS)

Blashenkov, N. M.; Sheshenya, E. S.; Solov'ev, S. M.; Sachenko, V. D.; Gall, L. N.; Zarutskii, I. V.; Gall, N. R.

2013-05-01

A specialized isotope mass spectrometer for noninvasive diagnostics of Helicobacter pylori infection in human beings based on the carbon-13 isotope breath test has been designed and constructed. Important stages of the work included (i) calculating a low-aberration mass analyzer, (ii) manufacturing and testing special gas inlet system, and (iii) creating a small-size collector of ions. The proposed instrument ensures 13C/12C isotopic ratio measurement to within 1.7‰ (pro mille) accuracy, which corresponds to requirements for a diagnostic tool. Preliminary medical testing showed that the mass spectrometer is applicable to practical diagnostics. The instrument is also capable of measuring isotopic ratios of other light elements, including N, O, B (for BF2+ ions), Ar, Cl, and S.

13C-methacetin-breath test compared to also noninvasive biochemical blood tests in predicting hepatic fibrosis and cirrhosis in chronic hepatitis C.

PubMed

Dinesen, L; Caspary, W F; Chapman, R W; Dietrich, C F; Sarrazin, C; Braden, B

2008-09-01

The (13)C-methacetin-breath test and also several noninvasive blood tests comprising routine laboratory parameters have been proposed to predict fibrosis and cirrhosis in chronic hepatitis C. The aim of the study was to compare the diagnostic accuracy between these tests referring to hepatic histology as gold standard. 96 patients with chronic hepatitis C virus infection underwent percutaneous liver biopsy and the (13)C-methacetin-breath test. The Fibroindex, the aspartate aminotransferase to platelet ratio index , and the aspartate aminotransferase to alanine aminotransferase ratio were used as parameters for the staging of fibrosis. The main endpoint was the area under the characteristic curves for the diagnosis of advanced fibrosis (F3-F4) and cirrhosis (F4) according to the Batts Ludwig criteria. ROC analysis revealed a cut-off <14.6 per thousand best with 92.6% sensitivity and 84.1% specificity for the (13)C-methacetin-breath test, for the Fibroindex >1.82 70.4% sensitivity and 91.3% specificity, for the aspartate aminotransferase to platelet ratio >1.0 a 66.7% sensitivity and 75.4% specificity, and for the aspartate aminotransferase to alanine aminotransferase ratio >1.0 63.0% sensitivity and 59.4% specificity in predicting liver cirrhosis. The areas under the curve for the breath test, the Fibroindex, aspartate aminotransferase to platelet ratio and the aspartate aminotransferase to alanine aminotransferase ratio were 0.958, 0.845, 0.799, and 0.688, respectively, when predicting cirrhosis. For identifying patients with advanced fibrosis, the areas under the curve were 0.827, 0.804, 0.779, and 0.561, respectively. Discordances between Fibroindex (21%), aspartate aminotransferase to platelet ratio (29%) or aspartate aminotransferase to alanine aminotransferase ratio (37.6%) and liver biopsy were significantly more frequent than between (13)C-breath test (11.6%) and liver biopsy (P<0.05). The (13)C-methacetin-breath test is more reliable in predicting advanced

Performance of acidified 14C-urea capsule breath test during pantoprazole and ranitidine treatment.

PubMed

Oztürk, Emel; Yeşilova, Zeki; Ilgan, Seyfettin; Ozgüven, Mehmet; Dağalp, Kemal

2009-07-01

Urea breath test (UBT) results could be false negative in patients taking antisecretory drugs. This effect would be prevented by citric acid administration during UBT. We prospectively investigated whether acidified 14C-urea capsule prevents false negative UBT results in patients taking antisecretory drugs and show interference with the duration of medications. Sixty Helicobacter pylori positive patients were included. Pantoprazole (40 mg/day) was given to 27 patients for 28 days and ranitidine (300 mg. o.d.) to 33 patients for 60 days. Urea breath tests were repeated on days 14 and 28 in both groups and on day 60 in the ranitidine group. The baseline mean breath counts of two groups did not show any significant difference. Pantoprazole led to a significant decrease in mean breath counts on day 14 (P < 0.005). Six of 27 and 3 of 25 patients taking pantoprazole developed negative or equivocal UBT results on days 14 and 28, respectively. Two of 32, 2 of 32 and 3 of 21 patients taking ranitidine developed negative or equivocal UBT results on days 14, 28 and 60, respectively. The use of acidified 14C-urea capsule did not prevent false negative UBT results in patients taking pantoprazole and ranitidine, and the duration of medication does not affect the test results.

A rapid non invasive L-DOPA-¹³C breath test for optimally suppressing extracerebral AADC enzyme activity - toward individualizing carbidopa therapy in Parkinson’s disease.

PubMed

Modak, Anil; Durso, Raymon; Josephs, Ephraim; Rosen, David

2012-01-01

Peripheral carbidopa (CD) levels directly impact on central dopamine (DA) production in Parkinson disease (PD) through extracerebral inhibition of dopa decarboxylase (AADC) resulting in an increase in levodopa (LD) bioavailability. Recent data suggests that higher CD doses than those presently used in PD treatment may result in improved clinical response. Optimizing CD doses in individual patients may, therefore, result in ideal individualized treatment. A single center, randomized, double-blind study was carried out recruiting 5 Parkinson’s disease (PD) patients already on LD/CD and 1 treatment näve PD patient using stable isotope labeled LD-1-¹³C as a substrate for a noninvasive breath test to evaluate individual AADC enzyme activity. Each patient was studied five times, receiving 200 mg LD-¹³C at each visit along with one of five randomized CD doses (0, 25, 50, 100 and 200 mg). The metabolite ¹³CO₂ in breath was measured for evaluating AADC enzyme activity and plasma metabolite levels for LD-¹³C and homovanillic acid (HVA) were measured for 4 hours. HVA in plasma and ¹³CO₂ in breath are metabolic products of LD. We found a significant positive correlation of ¹³CO₂ DOB AUC0-240 with serum HVA AUC0-240 following the oral dose of LD-1-¹³C for all 5 doses of CD (r² = 0.9378). With increasing inhibition of AADC enzyme activity with CD, we observed an increase in the plasma concentration of LD.We found an inverse correlation of the 13CO2 DOB AUC with serum LD-¹³C AUC. Our studies indicate the optimal dose of CD for maximal suppression of AADC enzyme activity can be determined for each individual from ¹³CO₂ generation in breath. The LD-breath test can be a useful noninvasive diagnostic tool for evaluation of AADC enzyme activity using the biomarker ¹³CO₂ in breath, a first step in personalizing CD doses for PD patients.

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.

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.

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

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.

Comparison of Accuracy Between 13C- and 14C-Urea Breath Testing: Is an Indeterminate-Results Category Still Needed?

PubMed

Charest, Mathieu; Bélair, Marc-André

2017-06-01

Helicobacter pylori infection is the leading cause of peptic ulcer disease. The purpose of this study was, first, to assess the difference in the distribution of negative versus positive results between the older 14 C-urea breath test and the newer 13 C-urea breath test and, second, to determine whether use of an indeterminate-results category is still meaningful and what type of results should trigger repeated testing. Methods: A retrospective survey was performed of all consecutive patients referred to our service for urea breath testing. We analyzed 562 patients who had undergone testing with 14 C-urea and 454 patients who had undergone testing with 13 C-urea. Results: In comparison with the wide distribution of negative 14 C results, negative 13 C results were distributed farther from the cutoff and were grouped more tightly around the mean negative value. Distribution analysis of the negative results for 13 C testing, compared with those for 14 C testing, revealed a statistically significant difference between the two. Within the 13 C group, only 1 patient could have been classified as having indeterminate results using the same indeterminate zone as was used for the 14 C group. This is significantly less frequent than what was found for the 14 C group. Discussion: Borderline-negative results do occur with 13 C-urea breath testing, although less frequently than with 14 C-urea breath testing, and we will be carefully monitoring differences falling between 3.0 and 3.5 %Δ. 13 C-urea breath testing is safe and simple for the patient and, in most cases, provides clearer positive or negative results for the clinician. © 2017 by the Society of Nuclear Medicine and Molecular Imaging.

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.

Does postprandial itopride intake affect the rate of gastric emptying? A crossover study using the continuous real time 13C breath test (BreathID system).

PubMed

Nonaka, Takashi; Kessoku, Takaomi; Ogawa, Yuji; Yanagisawa, Shogo; Shiba, Tadahiko; Sahaguchi, Takashi; Atsukawa, Kazuhiro; Takahashi, Hisao; Sekino, Yusuke; Iida, Hiroshi; Hosono, Kunihiro; Endo, Hiroki; Sakamoto, Yasunari; Koide, Tomoko; Takahashi, Hirokazu; Tokoro, Chikako; Abe, Yasunobu; Maeda, Shin; Nakajima, Atsushi; Inamori, Masahiko

2011-01-01

The aim of this study was to determine whether oral Itopride hydrochloride (itopride) intake might have any effect on the rate of gastric emptying, using a novel non-invasive technique for measuring the rate of gastric emptying, namely, the continuous real time 13C breath test (BreathID system: Exalenz Bioscience Ltd., Israel). Eight healthy male volunteers participated in this randomized, two-way crossover study. The subjects fasted overnight and were randomly assigned to receive 50mg itopride following a test meal (200 kcal per 200mL, containing 100mg 13C acetate), or the test meal alone. Under both conditions, gastric emptying was monitored for 4 hours after administration of the test meal by the 13C-acetic acid breath test performed continually using the BreathID system. Using Oridion Research Software (beta version), the time required for emptying of 50% of the labeled meal (T 1/2), the analog to the scintigraphy lag time for 10% emptying of the labeled meal (T lag), the gastric emptying coefficient (GEC), and the regression-estimated constants (beta and kappa) were calculated. The parameters measured under the two conditions were compared using the Wilcoxon's signed-rank test. No significant differences in the calculated parameters, namely, the T 1/2, T lag, GEC, beta or kappa, were observed between the two test conditions, namely, administration of a test meal+itopride and administration of the test meal alone. The present study revealed that postprandial itopride intake had no significant influence on the rate of gastric emptying. Recently, several studies have shown that itopride may be effective in the treatment of patients with functional dyspepsia. Our results suggest that the efficacy of itopride in patients with functional dyspepsia may be based on its effect of improving functions other than the rate of gastric emptying, such as the activities at neuronal sites, brain-gut correlation, visceral hypersensitivity, gastric accommodation and distension

Updating prognosis of cirrhosis by Cox's regression model using Child-Pugh score and aminopyrine breath test as time-dependent covariates.

PubMed

Merkel, C; Morabito, A; Sacerdoti, D; Bolognesi, M; Angeli, P; Gatta, A

1998-06-01

The determination of aminopyrine breath test on entry into the study was recently shown to improve the accuracy of prediction of death based on the Child-Pugh classification, but the possible usefulness of serial determinations of both parameters has not been assessed. In the present study, we aimed at evaluating whether serial determinations of aminopyrine breath test and Child-Pugh score improve prognostic accuracy in patients with cirrhosis, compared with determinations obtained only on admission. In 74 patients with liver cirrhosis aminopyrine breath test and Child-Pugh score were obtained upon entry into the study. Patients were followed with sequential aminopyrine breath tests and assessments of the Child-Pugh score every 4-6 months. A total number of 232 determinations were obtained. During follow-up 45 patients died, on average after 12 months of follow-up. Child-Pugh score improved in the beginning of follow-up, and then remained fairly constant; aminopyrine breath test showed no improvement in the beginning of follow-up, but rather a slowly progressive decline. In patients who died, both the Child-Pugh score and the metabolism of aminopyrine were significantly more impaired in the last year preceding death (p < 0.05). Applying Cox's regression model with time-dependent covariates, Child-Pugh score and aminopyrine breath test were independent significant predictors of survival. The model with time-dependent covariates explained the observed survival much better than the model with time-fixed covariates (chi-sq. explained by regression = 31.45 vs 11.97; d.f. = 2; p = 0.0000001 vs 0.003). These data suggest that serial determinations of Child-Pugh score and aminopyrine breath test can be used to efficiently update prognosis of cirrhosis.

Comparison between hyperventilation and breath-holding in panic disorder: patients responsive and non-responsive to both tests.

PubMed

Nardi, Antonio E; Valença, Alexandre M; Mezzasalma, Marco A; Levy, Sandra P; Lopes, Fabiana L; Nascimento, Isabella; Freire, Rafael C; Veras, Andre B; Zin, Walter A

2006-06-15

Our aim was to compare the demographic and psychopathological features of panic disorder (PD) patients who underwent hyperventilation and breath-holding challenge tests, and to describe the features of patients who had a panic attack after both tests versus those patients who did not experience panic after either test. Eighty-five PD patients were induced to hyperventilate (30 breaths/min) for 4 min, and a week later to hold their breath for as long as possible four times with a 2-min interval in between. Anxiety scales were applied before and after the tests. Patients who responded with a panic attack to both tests (BPA, n = 25) were compared with patients who experienced spontaneous panic attacks but did not panic in response to the two tests (NPA, n = 16). The BPA group had a significantly higher presence of respiratory symptoms during a panic attack. The criteria for the respiratory PD subtype were fulfilled in 18 (72.0%) BPA patients and in 6 (37.5%) NPA patients. The BPA patients had a later onset of panic disorder and a higher familial prevalence of PD. Our data suggest that there is a distinction between PD patients who were sensitive to both hyperventilation and breath-holding tests and PD patients who were not affected by the challenge tests. The panic attack may be a final common pathway for different types of stimuli, and respiratory tests may characterize different PD subgroups.

News from the Breath Analysis Summit 2011.

PubMed

Corradi, Massimo; Mutti, Antonio

2012-06-01

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

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

PubMed

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

2017-01-01

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

Measurement of breath acetone in patients referred for an oral glucose tolerance test.

PubMed

Andrews, Brian Terence; Denzer, Wolfgang; Hancock, Gus; Lunn, Dan; Peverall, Robert; Ritchie, Grant; Williams, Karen

2018-04-12

Breath acetone concentrations were measured in 141 subjects (aged 19-91 yrs, mean=59.11yrs standard deviation=12.99yrs), male and female, undergoing an oral glucose tolerance test (OGTT), having been referred to clinic on suspicion of type 2 diabetes. Breath samples were measured using an ion-molecule-reaction mass spectrometer, at the commencement of the OGTT, and after 1 and 2hrs. Subjects were asked to observe the normal routine before and during the OGTT, which includes an overnight fast and ingestion of 75g glucose at the beginning of the routine. Several groups of diagnosis were identified: type 2 Diabetes Mellitus positive (T2DM), n=22; impaired glucose intolerance (IGT), n=33; impaired fasting glucose (IFG), n=14; and reactive hypoglycaemia (RHG), n=5. The subjects with no diagnosis (i.e. normoglycaemia) were used as a control group, n=67. Distributions of breath acetone are presented for the different groups. There was no evidence of a direct relationship between blood glucose and acetone measurements at any time during the study (0hr: p=0.4482; 1hr: p=0.6854; and 2hr: p=0.1858). Nor were there significant differences between the measurements of breath acetone for the control group and the T2DM group (0hr: p=0.1759; 1hr: p=0.4521; and 2hr: p=0.7343). However, the ratio of breath acetone at 1hr to the initial breath acetone was found to be significantly different for the T2DM group compared to both the control and IGT groups (p=0.0189 and 0.011, respectively). The T2DM group was also found to be different in terms of ratio of breath acetone after 1hr to that at 2hrs during the OGTT. And was distinctive in that it showed a significant dependence upon the level of blood glucose at 2hrs (p=0.0146). We conclude that single measurements of the concentrations of breath acetone cannot be used as a potential screening diagnostic for T2DM diabetes in this cohort, but monitoring the evolution of breath acetone could open a non-invasive window to aid in the diagnosis

Bat breath reveals metabolic substrate use in free-ranging vampires.

PubMed

Voigt, Christian C; Grasse, Patricia; Rex, Katja; Hetz, Stefan K; Speakman, John R

2008-01-01

We analysed the stable carbon isotope ratio in exhaled CO(2) (delta(13)C(breath)) of free-ranging vampires to assess the type of metabolized substrate (endogenous or exogenous substrate) and its origin, i.e. whether the carbon atoms came from a C(4) food web (grass and cattle) or the C(3) food web in which they were captured (a rainforest remnant and its mammals). For an improved understanding of factors influencing the delta(13)C(breath) of vampires, we conducted feeding experiments with captive animals. The mean delta(13)C(breath) of starved bats was depleted in (13)C in relation to the diet by 4.6 per thousand (n = 10). Once fed with blood, delta(13)C(breath )levelled off within a short time approximately 2.2 per thousand above the stable carbon isotope signature of the diet. The median time required to exchange 50% of the carbon atoms in exhaled CO(2) with carbon atoms from the ingested blood was 18.6 min (mean 29.5 +/- 19.0 min, n = 5). The average delta(13)C of wing membrane and fur in free-ranging vampire bats suggested that bats almost exclusively foraged for cattle blood during the past weeks. The delta(13)C(breath) of the same bats averaged -19.1 per thousand. Given that all free-ranging vampires were starving and that the delta(13)C of cattle was more in enriched in (13)C by 5-6 per thousand than the delta(13)C(breath) of vampires, we conclude that the vampire bats of our study metabolised fat that was predominantly built from carbon atoms originating from cattle blood. Since delta(13)C of wing membrane and fur integrates over weeks and months respectively and delta(13)C(breath) over hours and days, we also conclude that vampire bats of the studied population consistently ignored rainforest mammals and chose cattle as their prey during and prior to our study.

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

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

PubMed

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

2016-01-01

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

Small intestinal malabsorption in chronic alcoholism: a retrospective study of alcoholic patients by the ¹⁴C-D-xylose breath test.

PubMed

Hope, Håvar; Skar, Viggo; Sandstad, Olav; Husebye, Einar; Medhus, Asle W

2012-04-01

The ¹⁴C-D-xylose breath test was used at Ullevål University Hospital in the period from 1986 TO 1995 for malabsorption testing. The objective of this retrospective study was to reveal whether patients with chronic alcoholism may have intestinal malabsorption. The consecutive ¹⁴C-D-xylose breath test database was reviewed and patients with the diagnosis of chronic alcoholism were identified. ¹⁴C-D-xylose breath test results of the alcoholic patients were compared with the results of untreated celiac patients and patient and healthy controls. In the ¹⁴C-D-xylose breath test, ¹⁴C-D-xylose was dissolved in water and given orally after overnight fast. Breath samples were taken at 30-min intervals for 210 min, and ¹⁴CO₂ : ¹²CO₂ ratios were calculated for each time point, presenting a time curve for ¹⁴C-D-xylose absorption. Urine was collected after 210 min and the fraction of the total d-xylose passed was calculated (U%). ¹⁴CO₂ in breath and ¹⁴C-D-xylose in urine were analyzed using liquid scintillation. Both breath and urine analysis revealed a pattern of malabsorption in alcoholics comparable with untreated celiac patients, with significantly reduced absorption of d-xylose compared with patient and healthy controls. Alcoholic patients have a significantly reduced ¹⁴C-D-xylose absorption, comparable with untreated celiac patients. This indicates a reduced intestinal function in chronic alcoholism.

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.

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.

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

PubMed

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

2015-11-01

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

Inward contaminant leakage tests of the S-Tron Corporation emergency escape breathing device.

DOT National Transportation Integrated Search

1992-04-01

At the request of S-Tron Corporation, to support their contract with the U.S. Navy, performance tests of the Emergency Escape Breathing Device (EEBD) were conducted in the Environmental Physiology Research Section contaminant leakage chamber. Sulfur ...

Establishment of a Quick and Highly Accurate Breath Test for ALDH2 Genotyping

PubMed Central

Aoyama, Ikuo; Ohashi, Shinya; Amanuma, Yusuke; Hirohashi, Kenshiro; Mizumoto, Ayaka; Funakoshi, Makiko; Tsurumaki, Mihoko; Nakai, Yukie; Tanaka, Katsuyuki; Hanada, Mariko; Uesaka, Aki; Chiba, Tsutomu; Muto, Manabu

2017-01-01

Objectives: Acetaldehyde, the first metabolite of ethanol, is a definite carcinogen for the esophagus, head, and neck; and aldehyde dehydrogenase 2 (ALDH2) is a mitochondrial enzyme that catalyzes the metabolism of acetaldehyde. The ALDH2 genotype exists as ALDH2*1/*1 (active ALDH2), ALDH2*1/*2 (heterozygous inactive ALDH2), and ALDH2*2/*2 (homozygous inactive ALDH2). Many epidemiological studies have reported that ALDH2*2 carriers are at high risk for esophageal or head and neck squamous cell carcinomas by habitual drinking. Therefore, identification of ALDH2*2 carriers would be helpful for the prevention of those cancers, but there have been no methods suitable for mass screening to identify these individuals. Methods: One hundred and eleven healthy volunteers (ALDH2*1/*1 carriers: 53; ALDH2*1/*2 carriers: 48; and ALDH2*2/*2 carriers: 10) were recruited. Breath samples were collected after drinking 100 ml of 0.5% ethanol using specially designed gas bags, and breath ethanol and acetaldehyde levels were measured by semiconductor gas chromatography. Results: The median (range) breath acetaldehyde levels at 1 min after alcohol ingestion were 96.1 (18.1–399.0) parts per billion (p.p.b.) for the ALDH2*1/*1 genotype, 333.5 (78.4–1218.4) p.p.b. for the ALDH2*1/*2 genotype, and 537.1 (213.2–1353.8) p.p.b. for the ALDH2*2/*2 genotype. The breath acetaldehyde levels in ALDH2*2 carriers were significantly higher than for the ALDH2*1/*1 genotype. Notably, the ratio of breath acetaldehyde level-to-breath ethanol level could identify carriers of the ALDH2*2 allele very accurately (whole accuracy; 96.4%). Conclusions: Our novel breath test is a useful tool for identifying ALDH2*2 carriers, who are at high risk for esophageal and head and neck cancers. PMID:28594397

Assessment of gastric emptying in non-obese diabetic mice using a [13C]-octanoic acid breath test.

PubMed

Creedon, Christopher T; Verhulst, Pieter-Jan; Choi, Kyoung M; Mason, Jessica E; Linden, David R; Szurszewski, Joseph H; Gibbons, Simon J; Farrugia, Gianrico

2013-03-23

Gastric emptying studies in mice have been limited by the inability to follow gastric emptying changes in the same animal since the most commonly used techniques require killing of the animals and postmortem recovery of the meal(1,2). This approach prevents longitudinal studies to determine changes in gastric emptying with age and progression of disease. The commonly used [(13)C]-octanoic acid breath test for humans(3) has been modified for use in mice(4-6) and rats(7) and we previously showed that this test is reliable and responsive to changes in gastric emptying in response to drugs and during diabetic disease progression(8). In this video presentation the principle and practical implementation of this modified test is explained. As in the previous study, NOD LtJ mice are used, a model of type 1 diabetes(9). A proportion of these mice develop the symptoms of gastroparesis, a complication of diabetes characterized by delayed gastric emptying without mechanical obstruction of the stomach(10). This paper demonstrates how to train the mice for testing, how to prepare the test meal and obtain 4 hr gastric emptying data and how to analyze the obtained data. The carbon isotope analyzer used in the present study is suitable for the automatic sampling of the air samples from up to 12 mice at the same time. This technique allows the longitudinal follow-up of gastric emptying from larger groups of mice with diabetes or other long-standing diseases.

Doubly labeled water method: in vivo oxygen and hydrogen isotope fractionation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schoeller, D.A.; Leitch, C.A.; Brown, C.

The accuracy and precision of the doubly labeled water method for measuring energy expenditure are influenced by isotope fractionation during evaporative water loss and CO/sub 2/ excretion. To characterize in vivo isotope fractionation, we collected and isotopically analyzed physiological fluids and gases. Breath and transcutaneous water vapor were isotopically fractionated. The degree of fractionation indicated that the former was fractionated under equilibrium control at 37/sup 0/C, and the latter was kinetically fractionated. Sweat and urine were unfractionated. By use of isotopic balance models, the fraction of water lost via fractionating routes was estimated from the isotopic abundances of body water,more » local drinking water, and dietary solids. Fractionated water loss averaged 23% (SD = 10%) of water turnover, which agreed with our previous estimates based on metabolic rate, but there was a systematic difference between the results based on O/sub 2/ and hydrogen. Corrections for isotopic fractionation of water lost in breath and (nonsweat) transcutaneous loss should be made when using labeled water to measure water turnover or CO/sub 2/ production.« less

Effect of DA-9701 on gastric emptying in a mouse model: assessment by ¹³C-octanoic acid breath test.

PubMed

Lim, Chul-Hyun; Choi, Myung-Gyu; Park, Hyeyeon; Baeg, Myong Ki; Park, Jae Myung

2013-07-21

To evaluate the effects of DA-9701 on the gastric emptying of a solid meal using the ¹³C-octanoic acid breath test in a mouse model. Male C57BL/6 mice aged > 8 wk and with body weights of 20-25 g were used in this study. The solid test meal consisted of 200 mg of egg yolk labeled with 1.5 L/g ¹³C-octanoic acid. The mice were placed in a 130 mL chamber flushed with air at a flow speed of 200 mL/min. Breath samples were collected for 6 h. The half-emptying time and lag phase were calculated using a modified power exponential model. To assess the reproducibility of the ¹³C-octanoic acid breath test, the breath test was performed two times at intervals of one week in ten mice without drug treatment. To assess the gastrokinetic effects of DA-9701, the breath test was performed three times in another twelve mice, with a randomized crossover sequence of three drug treatments: DA-9701 3 mg/kg, erythromycin 6 mg/kg, or saline. Each breath test was performed at an interval of one week. Repeatedly measured half gastric emptying time of ten mice without drug treatment showed 0.856 of the intraclass correlation coefficient for the half gastric emptying time (P = 0.004). The mean cumulative excretion curve for the ¹³C-octanoic acid breath test showed accelerated gastric emptying after DA-9701 treatment compared with the saline control (P = 0.028). The median half gastric emptying time after the DA-9701 treatment was significantly shorter than after the saline treatment [122.4 min (109.0-137.9 min) vs 134.5 min (128.4-167.0 min), respectively; P = 0.028] and similar to that after the erythromycin treatment [123.3 min (112.9-138.2 min)]. The lag phase, which was defined as the period taken to empty 15% of a meal, was significantly shorter after the DA-9701 treatment than after the saline treatment [48.1 min (44.6-57.1 min) vs 52.6 min (49.45-57.4 min), respectively; P = 0.049]. The novel prokinetic agent DA-9701 accelerated gastric emptying, assessed with repeated

Is breath acetone a biomarker of diabetes? A historical review on breath acetone measurements.

PubMed

Wang, Zhennan; Wang, Chuji

2013-09-01

Since the ancient discovery of the 'sweet odor' in human breath gas, pursuits of the breath analysis-based disease diagnostics have never stopped. Actually, the 'smell' of the breath, as one of three key disease diagnostic techniques, has been used in Eastern-Medicine for more than three thousand years. With advancement of measuring technologies in sensitivity and selectivity, more specific breath gas species have been identified and established as a biomarker of a particular disease. Acetone is one of the breath gases and its concentration in exhaled breath can now be determined with high accuracy using various techniques and methods. With the worldwide prevalence of diabetes that is typically diagnosed through blood testing, human desire to achieve non-blood based diabetic diagnostics and monitoring has never been quenched. Questions, such as is breath acetone a biomarker of diabetes and how is the breath acetone related to the blood glucose (BG) level (the golden criterion currently used in clinic for diabetes diagnostic, monitoring, and management), remain to be answered. A majority of current research efforts in breath acetone measurements and its technology developments focus on addressing the first question. The effort to tackle the second question has begun recently. The earliest breath acetone measurement in clearly defined diabetic patients was reported more than 60 years ago. For more than a half-century, as reviewed in this paper, there have been more than 41 independent studies of breath acetone using various techniques and methods, and more than 3211 human subjects, including 1581 healthy people, 242 Type 1 diabetic patients, 384 Type 2 diabetic patients, 174 unspecified diabetic patients, and 830 non-diabetic patients or healthy subjects who are under various physiological conditions, have been used in the studies. The results of the breath acetone measurements collected in this review support that many conditions might cause changes to breath

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.

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

PubMed

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

2015-12-15

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

Walk test and school performance in mouth-breathing children.

PubMed

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

2013-01-01

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

Validation of 13C-acetic acid breath test by measuring effects of loperamide, morphine, mosapride, and itopride on gastric emptying in mice.

PubMed

Matsumoto, Kenjiro; Kimura, Hiroshi; Tashima, Kimihito; Uchida, Masayuki; Horie, Syunji

2008-10-01

Several methods are used to evaluate gastric motility in rodents, but they all have technical limitations. Recent technical developments enable a convenient method to evaluate gastric motility. The (13)C-acetic acid breath test in rodents is a non-invasive and repeatable method that can be used without physical restraints. The present study aimed to validate the (13)C-acetic acid breath test by measuring the effects of loperamide, morphine, mosapride, and itopride on gastric emptying in mice. Loperamide (1-10 mg/kg) and morphine (1.25-10 mg/kg) slowed gastric emptying and decreased the maximum concentration (C(max)) and area under the curve (AUC(90 min)) value in a dose-dependent manner. Mosapride (0.2-5 mg/kg) accelerated gastric emptying and increased C(max) value. Mosapride (20 mg/kg) did not accelerate gastric emptying on the (13)C-breath test. Itopride (30 mg/kg, per os) significantly accelerated gastric emptying compared with the vehicle group. In a comparison with the conventional phenol red test, there was a correlation between the C(max) value of breath test and gastric emptying (%) of phenol red tests in treatment with loperamide or mosapride. These results indicate that the (13)C-acetic acid breath test is an accurate, noninvasive, and simple method for monitoring gastric emptying in mice. This method is useful to assess the effect of drugs and gut function pharmacologically.

Breath holding spell

MedlinePlus

... such as Riley-Day syndrome or Rett syndrome Iron deficiency anemia A family history of breath holding spells ( ... tests may be done to check for an iron deficiency. Other tests that may be done include: EKG ...

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

Code of Federal Regulations, 2011 CFR

2011-10-01

... test using a saliva ASD or a breath tube ASD? 40.245 Section 40.245 Transportation Office of the... 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 saliva...

Training in multiple breath washout testing for respiratory physiotherapists.

PubMed

O'Neill, Katherine; Elborn, J Stuart; Tunney, Michael M; O'Neill, Philip; Rowan, Stephen; Martin, Susan; Bradley, Judy M

2018-03-01

The development of multiple breath washout (MBW) testing in respiratory disease highlights the need for increased awareness amongst respiratory physiotherapists and a potential opportunity for professional development in the use of an important outcome measure for clinical trials. To rationalise how MBW may be a useful assessment tool for respiratory physiotherapists and to describe a local MBW training and certification programme for physiotherapists. The respiratory Multidisciplinary Team in the Belfast Health and Social Care Trust (BHSCT) identified a need for MBW testing to be available to facilitate clinical research and assessment. A 2day training programme consisting of prereading preparation, self-directed learning, theory presentations, practical demonstrations and hands-on practice was developed and delivered. All participants underwent a certification process. We have demonstrated the successful training and certification of clinical and research physiotherapists and encourage other respiratory physiotherapists to consider MBW test training. Copyright © 2017 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.

Isotope-labelled urea to test colon drug delivery devices in vivo: principles, calculations and interpretations.

PubMed

Maurer, Marina J M; Schellekens, Reinout C A; Wutzke, Klaus D; Stellaard, Frans

2013-01-01

This paper describes various methodological aspects that were encountered during the development of a system to monitor the in vivo behaviour of a newly developed colon delivery device that enables oral drug treatment of inflammatory bowel diseases. [(13)C]urea was chosen as the marker substance. Release of [(13)C]urea in the ileocolonic region is proven by the exhalation of (13)CO2 in breath due to bacterial fermentation of [(13)C]urea. The (13)CO2 exhalation kinetics allows the calculation of a lag time as marker for delay of release, a pulse time as marker for the speed of drug release and the fraction of the dose that is fermented. To determine the total bioavailability, also the fraction of the dose absorbed from the intestine must be quantified. Initially, this was done by calculating the time-dependent [(13)C]urea appearance in the body urea pool via measurement of (13)C abundance and concentration of plasma urea. Thereafter, a new methodology was successfully developed to obtain the bioavailability data by measurement of the urinary excretion rate of [(13)C]urea. These techniques required two experimental days, one to test the coated device, another to test the uncoated device to obtain reference values for the situation that 100 % of [(13)C]urea is absorbed. This is hampered by large day-to-day variations in urea metabolism. Finally, a completely non-invasive, one-day test was worked out based on a dual isotope approach applying a simultaneous administration of [(13)C]urea in a coated device and [(15)N2]urea in an uncoated device. All aspects of isotope-related analytical methodologies and required calculation and correction systems are described.

Diagnostic accuracy of the 14C-urea breath test in Helicobacter pylori infections: a meta-analysis.

PubMed

Zhou, Qiaohui; Li, Ling; Ai, Yaowei; Pan, Zhihong; Guo, Mingwen; Han, Jingbo

2017-01-01

To summarize and appraise the available literature regarding the use of the 14 C-urea breath test in the diagnosis of Helicobacter pylori infections in adult patients with dyspepsia and to calculate pooled diagnostic accuracy measures. We systematically searched the PubMed, EMBASE, Cochrane Library, Chinese Journals Full-text (CNKI) and CBMDisc databases to identify published data regarding the sensitivity, specificity, and other measures of diagnostic accuracy of the 14 C-urea breath test in the diagnosis of Helicobacter pylori infections in adult patients with dyspeptic symptoms. Risk of bias was assessed using the QUADAS (Quality Assessment of Diagnostic Accuracy Studies)-2 tool. Statistical analyses were performed using Meta-Disc 1.4 software and STATA. Eighteen studies met the inclusion criteria. Pooled results indicated that the  14 C-urea breath test showed a diagnostic sensitivity of 0.96 (95% CI 0.95 to 0.96) and specificity of 0.93 (95% CI 0.91 to 0.94). The positive like ratio (PLR) was 12.27 (95% CI 8.17 to 18.44), the negative like ratio (NLR) was 0.05 (95% CI 0.04 to 0.07), and the area under the curve was 0.985. The DOR was 294.95 (95% CI 178.37 to 487.70). The 14 C-urea breath test showed sufficient sensitivity and specificity for diagnosing Helicobacter pylori infection, but unexplained heterogeneity after meta-regression and several subgroup analyses remained. The UBT has high accuracy for diagnosing H. pylori infections in adult patients with dyspepsia. However, the reliability of these diagnostic meta-analytic estimates is limited by significant heterogeneity due to unknown factors.

A study of characteristics of a reliable and practical breath alcohol screening test. Part A

DOT National Transportation Integrated Search

1975-08-01

The objectives of this study were (1) to investigate several commercially available breath-alcohol screening test devices of the length-of-stain type, under standardized laboratory conditions, with respect to their ability satisfactorily to detect an...

Measurement of hepatic functional mass by means of 13C-methacetin and 13C-phenylalanine breath tests in chronic liver disease: Comparison with Child-Pugh score and serum bile acid levels

PubMed Central

Festi, D.; Capodicasa, S.; Sandri, L.; Colaiocco-Ferrante, L.; Staniscia, T.; Vitacolonna, E.; Vestito, A.; Simoni, P.; Mazzella, G.; Portincasa, P.; Roda, E.; Colecchia, A.

2005-01-01

AIM: To evaluate and compare the clinical usefulness of 13C-phenylalanine and 13C-methacetin breath tests in quantitating functional hepatic mass in patients with chronic liver disease and to further compare these results with those of conventional tests, Child-Pugh score and serum bile acid levels. METHODS: One hundred and forty patients (50 HCV- related chronic hepatitis, 90 liver cirrhosis patients) and 40 matched healthy controls were studied. Both breath test and routine liver test, serum levels of cholic and chenodeoxycholic acid conjugates were evaluated. RESULTS: Methacetin breath test, expressed as 60 min cumulative percent of oxidation, discriminated the hepatic functional capacity not only between controls and liver disease patients, but also between different categories of chronic liver disease patients. Methacetin breath test was correlated with liver function tests and serum bile acids. Furthermore, methacetin breath test, as well as serum bile acids, were highly predictive of Child-Pugh scores. The diagnostic power of phenylalanine breath test was always less than that of methacetin breath test. CONCLUSION: Methacetin breath test represents a safe and accurate diagnostic tool in the evaluation of hepatic functional mass in chronic liver disease patients. PMID:15609414

Isotope ratio mass spectrometry in nutrition research

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luke, A.H.

Many of the biochemical pathways and processes that form the foundation of modern nutrition research was elucidated using stable isotopes as physiological tracers. Since the discovery of stable isotopes, improvements and innovations in mass spectrometry and chromatography have led to greatly expanded applications. This research project was designed to evaluate gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS) as a tool for isotopic tracer studies and to delineate the operational parameters for the analysis of {sup 13}C-labeled cholesterol, leucine and {alpha}-ketoisocaproate. The same isotope ratio mass spectrometer was then used as the base instrument for the ratio mass spectrometer was then usedmore » as the base instrument for the development of two additional inlet systems: a continuous-flow inlet for the analyses of {sup 13}C and {sup 18}O as CO{sub 2} and a filament inlet for on-line combustion and isotopic analysis of non-volatile organic compounds. Each of these three inlets was evaluated and their utility in nutrition research illustrated. GC/C/IRMS was used to analyze cholesterol, leucine and {alpha}-ketoisocaproate with good accuracy, precision and little isotopic memory. For all three compounds the detection limits achieved well surpassed currently used technologies. For compounds that can be well separated by GC, GC/C/IRMS is a valuable analytical tool. The continuous-flow inlet provided good accuracy and precision for measurements of {sup 13}CO{sub 2} from breath tests and {sup 18}O as CO{sub 2} from total energy expenditure tests. Most importantly, the continuous-flow inlet increased sample throughput by at least a factor of three over conventional analytical techniques. The filament inlet provided accurate and precise {sup 13}C ratio measurements of both natural abundance and enriched standards of non-volatile organic compounds of physiological interest.« less

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

PubMed

Glinn, Michele; Adatsi, Felix; Curtis, Perry

2011-11-01

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

TR-BREATH: Time-Reversal Breathing Rate Estimation and Detection.

PubMed

Chen, Chen; Han, Yi; Chen, Yan; Lai, Hung-Quoc; Zhang, Feng; Wang, Beibei; Liu, K J Ray

2018-03-01

In this paper, we introduce TR-BREATH, a time-reversal (TR)-based contact-free breathing monitoring system. It is capable of breathing detection and multiperson breathing rate estimation within a short period of time using off-the-shelf WiFi devices. The proposed system exploits the channel state information (CSI) to capture the miniature variations in the environment caused by breathing. To magnify the CSI variations, TR-BREATH projects CSIs into the TR resonating strength (TRRS) feature space and analyzes the TRRS by the Root-MUSIC and affinity propagation algorithms. Extensive experiment results indoor demonstrate a perfect detection rate of breathing. With only 10 s of measurement, a mean accuracy of can be obtained for single-person breathing rate estimation under the non-line-of-sight (NLOS) scenario. Furthermore, it achieves a mean accuracy of in breathing rate estimation for a dozen people under the line-of-sight scenario and a mean accuracy of in breathing rate estimation of nine people under the NLOS scenario, both with 63 s of measurement. Moreover, TR-BREATH can estimate the number of people with an error around 1. We also demonstrate that TR-BREATH is robust against packet loss and motions. With the prevailing of WiFi, TR-BREATH can be applied for in-home and real-time breathing monitoring.

Lactulose Breath Test Gas Production in Childhood IBS Is Associated With Intestinal Transit and Bowel Movement Frequency.

PubMed

Chumpitazi, Bruno P; Weidler, Erica M; Shulman, Robert J

2017-04-01

In adults with irritable bowel syndrome (IBS), bacterial gas production (colonic fermentation) is related to both symptom generation and intestinal transit. Whether gas production affects symptom generation, psychosocial distress, or intestinal transit in childhood IBS is unknown. Children (ages 7-17 years) with pediatric Rome III IBS completed validated psychosocial questionnaires and a 2-week daily diary capturing pain and stooling characteristics. Stool form determined IBS subtype. Subjects then completed a 3-hour lactulose breath test for measurement of total breath hydrogen and methane production. Carmine red was used to determine whole intestinal transit time. A total of 87 children (mean age 13 ± 2.6 [standard deviation] years) were enrolled, of whom 50 (57.5%) were girls. All children produced hydrogen and 51 (58.6%) produced methane. Hydrogen and methane production did not correlate with either abdominal pain frequency/severity or psychosocial distress. Hydrogen and methane production did not differ significantly by IBS subtype. Methane production correlated positively with whole intestinal transit time (r = 0.31, P < 0.005) and inversely with bowel movement frequency (r = -0.245, P < 0.05). Methane production (threshold 3 ppm) as a marker for identifying IBS-C had a sensitivity of 60% and specificity of 42.9%. Lactulose breath test total methane production may serve as a biomarker of whole intestinal transit time and bowel movement frequency in children with IBS. In children with IBS, lactulose breath test hydrogen and methane production did not, however, correlate with abdominal pain, IBS subtype, or psychosocial distress.

Breath-to-breath hypercapnic response in neonatal rats: temperature dependency of the chemoreflexes and potential implications for breathing stability.

PubMed

Cummings, Kevin J; Frappell, Peter B

2009-07-01

The breathing of newborns is destabilized by warm temperatures. We hypothesized that in unanesthetized, intact newborn rats, body temperature (T(B)) influences the peripheral chemoreflex response (PCR response) to hypercapnia. To test this, we delivered square-wave challenges of 8% CO(2) in air to postnatal day 4-5 (P4-P5) rats held at a T(B) of 30 degrees C (Cold group, n = 11), 33 degrees C (Cool group, n = 10), and 35 degrees C thermoneutral zone group [thermoneutral zone (TNZ) group, n = 11], while measuring ventilation (Ve) directly with a pneumotach and mask. Cool animals were challenged with 8% CO(2) balanced in either air or hyperoxia (n = 10) to identify the PCR response. Breath-to-breath analysis was performed on 30 room air breaths and every breath of the 1-min CO(2) challenge. As expected, warmer T(B) was associated with an unstable breathing pattern in room air: TNZ animals had a coefficient of variation in Ve (Ve CV%) that was double that of animals held at cooler T(B) (P < 0.001). Hyperoxia markedly suppressed the hypercapnic ventilatory response over the first 10 breaths (or approximately 4 s), suggesting that this domain is dominated by the PCR response. The PCR response (P = 0.03) and total response (P = 0.04) were significantly greater in TNZ animals compared with hypothermic animals. The total response had a significant, negative relationship with Vco(2) (R(2) = 0.53; P < 0.001). Breathing stability was positively related to the total response (R(2) = 0.36; P < 0.001) and to a lesser extent, the PCR response (R(2) = 0.19; P = 0.01) and was negatively related to Vco(2) (R(2) = 0.34; P < 0.001). ANCOVA confirmed a significant effect of T(B) alone on breathing stability (P < 0.01), with no independent effects of Vco(2) (P = 0.41), the PCR response (P = 0.82), or the total Ve response (P = 0.08). Our data suggest that in early postnatal life, the chemoreflex responses to CO(2) are highly influenced by T(B), and while related to breathing stability

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

Does smoking abstinence influence distress tolerance? An experimental study comparing the response to a breath-holding test of smokers under tobacco withdrawal and under nicotine replacement therapy.

PubMed

Cosci, Fiammetta; Anna Aldi, Giulia; Nardi, Antonio Egidio

2015-09-30

Distress tolerance has been operationalized as task persistence in stressful behavioral laboratory tasks. According to the distress tolerance perspective, how an individual responds to discomfort/distress predicts early smoking lapses. This theory seems weakly supported by experimental studies since they are limited in number, show inconsistent results, do not include control conditions. We tested the response to a stressful task in smokers under abstinence and under no abstinence to verify if tobacco abstinence reduces task persistence, thus distress tolerance. A placebo-controlled, double-blind, randomized, cross-over design was used. Twenty smokers underwent a breath holding test after the administration of nicotine on one test day and a placebo on another test day. Physiological and psychological variables were assessed at baseline and directly before and after each challenge. Abstinence induced a statistically significant shorter breath holding duration relative to the nicotine condition. No different response to the breath holding test was observed when nicotine and placebo conditions were compared. No response to the breath holding test was found when pre- and post-test values of heart rate, blood pressure, Visual Analogue Scale for fear or discomfort were compared. In brief, tobacco abstinence reduces breath holding duration but breath holding test does not influence discomfort. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

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

PubMed

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

2013-03-05

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. 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. 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/or peptic ulcer, as compared

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

Code of Federal Regulations, 2011 CFR

2011-07-01

...) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Traffic Supervision § 634.37 Voluntary breath and bodily fluid testing based on implied consent... the person was driving under the influence of alcohol or drugs. (3) A request was made to the person...

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

Code of Federal Regulations, 2010 CFR

2010-07-01

...) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Traffic Supervision § 634.37 Voluntary breath and bodily fluid testing based on implied consent... the person was driving under the influence of alcohol or drugs. (3) A request was made to the person...

Kilowatt Isotope Power System: component test report for the Ground Demonstration System Alternator Stator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brainard, E.L.

1978-04-25

Results are presented of acceptance tests conducted on the Alternator Stator, S/N 002, for the Kilowatt Isotope Power System. These results show that the Alternator Stator, S/N 002 for the Kilowatt Isotope Power System has satisfactorily completed the testing set forth within Sundstrand Test Specification 2538. Test requirements of TS 2538 were extracted from the Kilowatt Isotope Power System, and Phase I Test Plan.

Sensing the effects of mouth breathing by using 3-tesla MRI

NASA Astrophysics Data System (ADS)

Park, Chan-A.; Kang, Chang-Ki

2017-06-01

We investigated the effects of mouth breathing and typical nasal breathing on brain function by using blood-oxygenation-level-dependent (BOLD) functional magnetic resonance imaging (fMRI). The study had two parts: the first test was a simple contrast between mouth and nasal breathing, and the second test involved combined breathing modes, e.g., mouth inspiration and nasal expiration. Eleven healthy participants performed the combined breathing task while undergoing 3T fMRI. In the group-level analysis, contrast images acquired by using an individual participantlevel analysis were processed using the one-sample t test. We also conducted a region-of-interest analysis comparing signal intensity changes between the breathing modes; the region was selected using an automated anatomical labeling map. The results demonstrated that the BOLD signal in the hippocampus and brainstem was significantly decreased in mouth breathing relative to nasal breathing. On the other hand, both the precentral and postcentral gyri showed activation that was more significant in mouth breathing compared to nasal breathing. This study suggests that the BOLD activity patterns between mouth and nasal breathing may be induced differently, especially in the hippocampus, which could provide clues to explain the effects on brain cognitive function due to mouth breathing.

Random breath testing in Australia: getting it to work according to specifications.

PubMed

Homel, R

1993-01-01

After reading the deterrence literature, particularly the work of H. Laurence Ross, I concluded in the late 1970's that many road accidents could be prevented through the wholehearted implementation of random breath testing (RBT). RBT is a system of drink-drive law enforcement which aims to increase the perceived likelihood of apprehension through the use of mass breath testing techniques at roadblocks which are highly visible, are unpredictable in their locations and give the impression of ubiquity. As the result of public pressure, RBT was introduced in NSW in December 1982, with spectacular results. The law was intensively enforced and extensively advertised, partly due to the advocacy of researchers such as myself, but also because ther was an acute political need for instant results. Since RBT is a difficult enforcement technique for police to sustain in effective form, researchers must strive to improve their understanding of what works, and remain in close contact with police, policy makers and politicians. Although this process is costly in terms of time and, possibly, academic 'pay-off', it is essential if the fragile understanding of deterrence principles amongst these groups is not to lead to superficially attractive, but probably ineffective techniques such as low visibility mobile RBT.

Direct comparison of solid-phase gastric emptying times assessed by means of a carbon isotope-labeled sodium acetate breath test and technetium Tc 99m albumin colloid radioscintigraphy in healthy cats.

PubMed

Schmitz, Silke; Götte, Birte; Borsch, Christian; Kunz, Clemens; Failing, Klaus; Neiger, Reto

2014-07-01

To directly compare solid-phase gastric emptying times assessed by means of a [(13)C]sodium acetate breath test ([(13)C]-SABT) and technetium Tc 99m albumin colloid radioscintigraphy ((99m)Tc-ACR) in healthy cats. 12 healthy cats. After ingestion of a test meal containing 50 mg of [(13)C]sodium acetate and 250 MBq of (99m)Tc-albumin colloid, each cat underwent simultaneous [(13)C]-SABT and (99m)Tc-ACR on 2 consecutive days. Breath samples and scintigrams were acquired at 30, 60, 90, 120, 150, 180, 210, 240, 300, 360, 480, and 600 minutes after meal ingestion. Quartiles of gastric emptying (25%, 50%, and 75%) were calculated for breath test analysis by use of the area under the curve of the (13)C:(12)C ratio. Quartiles of gastric emptying times were extrapolated from the scintigraphic findings by beans of nonlinear curve regression analysis. Mean ± SD gastric half-emptying (50%) times obtained with [(13)C]-SABT and (99m)Tc-ACR, were 239 ± 28 minutes and 276 ± 59 minutes, respectively. A 2-way repeated-measures ANOVA revealed that mean gastric emptying times determined with [(13)C]-SABT and (99m)Tc-ACR differed significantly. For the stages of gastric emptying, Pearson correlation between the 2 methods was good at 25% (r = 0.655) and weak at 50% (r = 0.588) and 75% (r = 0.566)of gastric emptying. Results indicated that the [(13)C]-SABT can be a valid alternative to (99m)Tc-ACR in healthy cats; it was easy to perform, was tolerated well by the cats, and had acceptable correlation to scintigraphic findings at gastric emptying of 25%, 50% and 75%. Studies in cats with delayed gastric emptying will be needed to verify the validity of the [(13)C]-SABT.

Breath measurement instrumentation as alcohol safety interlock systems

DOT National Transportation Integrated Search

1974-09-01

This report describes the results of field tests of in-car instruments which measure alcohol on the driver's breath and prevent him from operating his vehicle if intoxicated. Two types of breath alcohol sensors were used for these tests; a fuel-cell ...

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.

A comparison of blood alcohol levels as determined by breath and blood tests taken in actual field operations.

DOT National Transportation Integrated Search

1972-01-01

During its 1972 session, the General Assembly of Virginia enacted Senate Bill 104, which authorizes the breath test, as well as the blood test used previously, as a proper chemical test to determine the alcoholic content of the blood. Any person arre...

A breath test for malignant mesothelioma using an electronic nose.

PubMed

Chapman, Eleanor A; Thomas, Paul S; Stone, Emily; Lewis, Craig; Yates, Deborah H

2012-08-01

Malignant mesothelioma (MM) is a rare tumour which is difficult to diagnose in its early stages. Earlier detection of MM could potentially improve survival. Exhaled breath sampling of volatile organic compounds (VOCs) using a carbon polymer array (CPA) electronic nose recognises specific breath profiles characteristic of different diseases, and can distinguish between patients with lung cancer and controls. With MM, the potential confounding effect of other asbestos-related diseases (ARDs) needs to be considered. We hypothesised that as CPA electronic nose would distinguish patients with MM, patients with benign ARDs, and controls with high sensitivity and specificity. 20 MM, 18 ARD and 42 control subjects participated in a cross-sectional, case-control study. Breath samples were analysed using the Cyranose 320 (Smiths Detection, Pasadena, CA, USA), using canonical discriminant analysis and principal component reduction. 10 MM subjects created the training set. Smell prints from 10 new MM patients were distinguished from control subjects with an accuracy of 95%. Patients with MM, ARDs and control subjects were correctly identified in 88% of cases. Exhaled breath VOC profiling can accurately distinguish between patients with MM, ARDs and controls using a CPA electronic nose. This could eventually translate into a screening tool for high-risk populations.

Carbon isotopes in biological carbonates: Respiration and photosynthesis

USGS Publications Warehouse

McConnaughey, T.A.; Burdett, J.; Whelan, J.F.; Paull, C.K.

1997-01-01

Respired carbon dioxide is an important constituent in the carbonates of most air breathing animals but is much less important in the carbonates of most aquatic animals. This difference is illustrated using carbon isotope data from freshwater and terrestrial snails, ahermatypic corals, and chemoautotrophic and methanotrophic pelecypods. Literature data from fish otoliths and bird and mammal shell and bone carbonates are also considered. Environmental CO2/O2 ratios appear to be the major controlling variable. Atmospheric CO2/O2 ratios are about thirty times lower than in most natural waters, hence air breathing animals absorb less environmental CO2 in the course of obtaining O2. Tissue CO2 therefore, does not isotopically equilibrate with environmental CO2 as thoroughly in air breathers as in aquatic animals, and this is reflected in skeletal carbonates. Animals having efficient oxygen transport systems, such as vertebrates, also accumulate more respired CO2 in their tissues. Photosynthetic corals calcify mainly during the daytime when photosynthetic CO2 uptake is several times faster than respiratory CO2 release. Photosynthesis, therefore, affects skeletal ??13C more strongly than does respiration. Corals also illustrate how "metabolic" effects on skeletal isotopic composition can be estimated, despite the presence of much larger "kinetic" isotope effects. Copyright ?? 1997 Elsevier Science Ltd.

Carbon isotopes in biological carbonates: Respiration and photosynthesis

NASA Astrophysics Data System (ADS)

McConnaughey, Ted A.; Burdett, Jim; Whelan, Joseph F.; Paull, Charles K.

1997-02-01

Respired carbon dioxide is an important constituent in the carbonates of most air breathing animals but is much less important in the carbonates of most aquatic animals. This difference is illustrated using carbon isotope data from freshwater and terrestrial snails, ahermatypic corals, and chemoautotrophic and methanotrophic pelecypods. Literature data from fish otoliths and bird and mammal shell and bone carbonates are also considered. Environmental CO 2/O 2 ratios appear to be the major controlling variable. Atmospheric CO 2/O 2 ratios are about thirty times lower than in most natural waters, hence air breathing animals absorb less environmental CO 2 in the course of obtaining 0 2. Tissue CO 2 therefore, does not isotopically equilibrate with environmental CO 2 as thoroughly in air breathers as in aquatic animals, and this is reflected in skeletal carbonates. Animals having efficient oxygen transport systems, such as vertebrates, also accumulate more respired CO 2 in their tissues. Photosynthetic corals calcify mainly during the daytime when photosynthetic CO 2 uptake is several times faster than respiratory CO 2 release. Photosynthesis, therefore, affects skeletal δ13C more strongly than does respiration. Corals also illustrate how "metabolic" effects on skeletal isotopic composition can be estimated, despite the presence of much larger "kinetic" isotope effects.

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

NASA Astrophysics Data System (ADS)

Mehta, U.

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.

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

Exhaled breath analysis for lung cancer

PubMed Central

Sutedja, Tom G.; Zimmerman, Paul V.

2013-01-01

Early diagnosis of lung cancer results in improved survival compared to diagnosis with more advanced disease. Early disease is not reliably indicated by symptoms. Because investigations such as bronchoscopy and needle biopsy have associated risks and substantial costs, they are not suitable for population screening. Hence new easily applicable tests, which can be used to screen individuals at risk, are required. Biomarker testing in exhaled breath samples is a simple, relatively inexpensive, non-invasive approach. Exhaled breath contains volatile and non-volatile organic compounds produced as end-products of metabolic processes and the composition of such compounds varies between healthy subjects and subjects with lung cancer. Many studies have analysed the patterns of these compounds in exhaled breath. In addition studies have also reported that the exhaled breath condensate (EBC) can reveal gene mutations or DNA abnormalities in patients with lung cancer. This review has summarised the scientific evidence demonstrating that lung cancer has distinct chemical profiles in exhaled breath and characteristic genetic changes in EBC. It is not yet possible to accurately identify individuals with lung cancer in at risk populations by any of these techniques. However, analysis of both volatile organic compounds in exhaled breath and of EBC have great potential to become clinically useful diagnostic and screening tools for early stage lung cancer detection. PMID:24163746

13C-Labeled-Starch Breath Test in Congenital Sucrase-isomaltase Deficiency.

PubMed

Robayo-Torres, Claudia C; Diaz-Sotomayor, Marisela; Hamaker, Bruce R; Baker, Susan S; Chumpitazi, Bruno P; Opekun, Antone R; Nichols, Buford L

2018-06-01

Human starch digestion is a multienzyme process involving 6 different enzymes: salivary and pancreatic α-amylase; sucrase and isomaltase (from sucrose-isomaltase [SI]), and maltase and glucoamylase (from maltase-glucoamylase [MGAM]). Together these enzymes cleave starch to smaller molecules ultimately resulting in the absorbable monosaccharide glucose. Approximately 80% of all mucosal maltase activity is accounted for by SI and the reminder by MGAM. Clinical studies suggest that starch may be poorly digested in those with congenital sucrase-isomaltase deficiency (CSID). Poor starch digestion occurs in individuals with CSID and can be documented using a noninvasive C-breath test (BT). C-Labled starch was used as a test BT substrate in children with CSID. Sucrase deficiency was previously documented in study subjects by both duodenal biopsy enzyme assays and C-sucrose BT. Breath CO2 was quantitated at intervals before and after serial C-substrate loads (glucose followed 75 minutes later by starch). Variations in metabolism were normalized against C-glucose BT (coefficient of glucose absorption). Control subjects consisted of healthy family members and a group of children with functional abdominal pain with biopsy-proven sucrase sufficiency. Children with CSID had a significant reduction of C-starch digestion mirroring that of their duodenal sucrase and maltase activity and C-sucrase BT. In children with CSID, starch digestion may be impaired. In children with CSID, starch digestion correlates well with measures of sucrase activity.

Breathing exercises for dysfunctional breathing/hyperventilation syndrome in adults.

PubMed

Jones, Mandy; Harvey, Alex; Marston, Louise; O'Connell, Neil E

2013-05-31

Dysfunctional breathing/hyperventilation syndrome (DB/HVS) is a respiratory disorder, psychologically or physiologically based, involving breathing too deeply and/or too rapidly (hyperventilation) or erratic breathing interspersed with breath-holding or sighing (DB). DB/HVS can result in significant patient morbidity and an array of symptoms including breathlessness, chest tightness, dizziness, tremor and paraesthesia. DB/HVS has an estimated prevalence of 9.5% in the general adult population, however, there is little consensus regarding the most effective management of this patient group. (1) To determine whether breathing exercises in patients with DB/HVS have beneficial effects as measured by quality of life indices (2) To determine whether there are any adverse effects of breathing exercises in patients with DB/HVS SEARCH METHODS: We identified trials for consideration using both electronic and manual search strategies. We searched CENTRAL, MEDLINE, EMBASE, and four other databases. The latest search was in February 2013. We planned to include randomised, quasi-randomised or cluster randomised controlled trials (RCTs) in which breathing exercises, or a combined intervention including breathing exercises as a key component, were compared with either no treatment or another therapy that did not include breathing exercises in patients with DB/HVS. Observational studies, case studies and studies utilising a cross-over design were not eligible for inclusion.We considered any type of breathing exercise for inclusion in this review, such as breathing control, diaphragmatic breathing, yoga breathing, Buteyko breathing, biofeedback-guided breathing modification, yawn/sigh suppression. Programs where exercises were either supervised or unsupervised were eligible as were relaxation techniques and acute-episode management, as long as it was clear that breathing exercises were a key component of the intervention.We excluded any intervention without breathing exercises or

Novel diagnostics of metabolic dysfunction detected in breath and plasma by selective isotope-assisted labeling.

PubMed

Haviland, Julia A; Tonelli, Marco; Haughey, Dermot T; Porter, Warren P; Assadi-Porter, Fariba M

2012-08-01

Metabolomics is the study of a unique fingerprint of small molecules present in biological systems under healthy and disease conditions. One of the major challenges in metabolomics is validation of fingerprint molecules to identify specifically perturbed pathways in metabolic aberrations. This step is crucial to the understanding of budding metabolic pathologies and the ability to identify early indicators of common diseases such as obesity, type 2 diabetes mellitus, metabolic syndrome, polycystic ovary syndrome, and cancer. We present a novel approach to diagnosing aberrations in glucose utilization including metabolic pathway switching in a disease state. We used a well-defined prenatally exposed glucocorticoid mouse model that results in adult females with metabolic dysfunction. We applied the complementary technologies of nuclear magnetic resonance spectroscopy and cavity ring-down spectroscopy to analyze serial plasma samples and real-time breath measurements following selective (13)C-isotope-assisted labeling. These platforms allowed us to trace metabolic markers in whole animals and identify key metabolic pathway switching in prenatally glucocorticoid-treated animals. Total glucose flux is significantly proportionally increased through the major oxidative pathways of glycolysis and the pentose phosphate pathway in the prenatally glucocorticoid-treated animals relative to the control animals. This novel diagnostics approach is fast, noninvasive, and sensitive for determining specific pathway utilization, and provides a direct translational application in the health care field. Copyright © 2012 Elsevier Inc. All rights reserved.

Effect of Yogic Breathing on Accommodate Braille Version of Six-letter Cancellation Test in Students with Visual Impairment.

PubMed

Pradhan, Balaram; Mohanty, Soubhagyalaxmi; Hankey, Alex

2018-01-01

Attentional processes tend to be less well developed in the visually impaired, who require special training to develop them fully. Yogic breathing which alters the patterns of respiration has been shown to enhance attention skills. Letter cancellation tests are well-established tools to measure attention and attention span. Here, a modified Braille version of the six-letter cancellation test (SLCT) was used for students with visual impairment (VI). This study aimed to assess the immediate effects of Bhramari Pranayama (BhPr) and breath awareness (BA) on students with VI. This study was a self-as-control study held on 2 consecutive days, on 19 participants (8 males, 11 females), with a mean age of 15.89 ± 1.59 years, randomized into two groups. On the 1 st day, Group 1 performed 10 min breath awareness and Group 2 performed Bhramari ; on the 2 nd day, practices were reversed. Assessments used a SLCT specially adapted for the visually impaired before and after each session. The Braille letter cancellation test was successfully taken by 19 students. Scores significantly improved after both techniques for each student following practices on both days ( P < 0.001). BhPr may have more effect on attention performance than BA as wrong scores significantly increased following BA ( P < 0.05), but the increase in the score after Bhramari was not significant. Despite the small sample size improvement in attentional processes by both yoga breathing techniques was robust. Attentional skills were definitely enhanced. Long-term practice should be studied.

Effect of Yogic Breathing on Accommodate Braille Version of Six-letter Cancellation Test in Students with Visual Impairment

PubMed Central

Pradhan, Balaram; Mohanty, Soubhagyalaxmi; Hankey, Alex

2018-01-01

Context: Attentional processes tend to be less well developed in the visually impaired, who require special training to develop them fully. Yogic breathing which alters the patterns of respiration has been shown to enhance attention skills. Letter cancellation tests are well-established tools to measure attention and attention span. Here, a modified Braille version of the six-letter cancellation test (SLCT) was used for students with visual impairment (VI). Aim: This study aimed to assess the immediate effects of Bhramari Pranayama (BhPr) and breath awareness (BA) on students with VI. Methods: This study was a self-as-control study held on 2 consecutive days, on 19 participants (8 males, 11 females), with a mean age of 15.89 ± 1.59 years, randomized into two groups. On the 1st day, Group 1 performed 10 min breath awareness and Group 2 performed Bhramari; on the 2nd day, practices were reversed. Assessments used a SLCT specially adapted for the visually impaired before and after each session. Results: The Braille letter cancellation test was successfully taken by 19 students. Scores significantly improved after both techniques for each student following practices on both days (P < 0.001). BhPr may have more effect on attention performance than BA as wrong scores significantly increased following BA (P < 0.05), but the increase in the score after Bhramari was not significant. Conclusions: Despite the small sample size improvement in attentional processes by both yoga breathing techniques was robust. Attentional skills were definitely enhanced. Long-term practice should be studied. PMID:29755219

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.

Quiet breathing in hindlimb casted mice.

PubMed

Receno, Candace N; Roffo, Katelynn E; Mickey, Marisa C; DeRuisseau, Keith C; DeRuisseau, Lara R

2018-06-07

The hindlimb casting model was developed to study skeletal muscle reloading following a period of unloading. It is unknown if ventilation parameters of mice are affected by the casting model. We tested the hypothesis that hindlimb casted mice have similar ventilatory patterns compared to mice with the casts removed. Male CD-1 mice underwent 14 days of hindlimb immobilization via plaster casting. Breathing parameters were obtained utilizing unrestrained barometric plethysmography (UBP). Breathing traces were analyzed with Ponemah software for breathing frequency, tidal volume (TV), and minute ventilation (MV). Frequency, TV and MV did not show any differences in quiet breathing patterns during or post-casting in mice. Thus, the hindlimb casting model does not complicate breathing during and after casting and should not interfere with the unloading and reloading of skeletal muscle. Copyright © 2018 Elsevier B.V. All rights reserved.

Evaluation of innovative state and community alcohol projects : breath alcohol testing program effectiveness, impact and transferability

DOT National Transportation Integrated Search

1987-03-01

Breath Alcohol Testing (BAT) programs in Albuquerque and Santa Fe, New Mexico are evaluated in regard to effectiveness, impact, and transferability of the special DWI enforcement squads and their use of BAT Mobiles. Squad activity effectiveness is me...

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.

Synthesis of ¹³C-lidocaine as a probe of breath test for the evaluation of cytochrome P450 activity.

PubMed

Mitome, Hidemichi; Sugiyama, Erika; Sato, Hitoshi; Akira, Kazuki

2014-01-01

(13)C-Labeled lidocaine, 2-di[1-(13)C]ethylamino-N-(2,6-dimethylphenyl)acetamide (1), was synthesized from [1-(13)C]acetic acid in six steps, as a probe for a breath test to evaluate in vivo cytochrome P450 activity. The measurement of (13)CO2 in breath was successfully performed following oral administration of (13)C-lidocaine 1 to mice.

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

PubMed Central

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

2011-01-01

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

Comparison of an increased waist circumference with a positive hydrogen breath test as a clinical predictor of lactose intolerance.

PubMed

Zapata-Castilleja, Carlos A; Montes-Tapia, Fernando F; Treviño-Garza, Consuelo; Martínez-Cobos, María C; García-Cantú, Jesús; Arenas-Fabbri, Vincenzo; de la O-Escamilla, Norma; de la O-Cavazos, Manuel

2017-04-01

Lactose intolerance is a common disease in pediatrics, and its wrong diagnosis will lead to morbidity. The primary objective of this study was to assess the usefulness of an increased waist circumference during the hydrogen breath test as a predictor of lactose intolerance. The secondary objective was to analyze the impact of body mass index, waist circumference measurement, and age on the abdominal distension of patients with lactose intolerance. A total of 138 subjects aged 3 to 15 years were included. They underwent serial measurements of the waist circumference and hydrogen levels in the breath every 30 minutes over 3 hours during the hydrogen breath test. Out of the entire sample, 35 (25.4%) patients had lactose intolerance. An increase of 0.85 cm in waist circumference compared to the baseline waist circumference results in a sensitivity of 88% and a specificity of 85% to predict lactose intolerance (odds ratio: 42.14, 95% confidence interval: 13.08-135.75, p ≤ 0.001). The body mass index and waist circumference measurement did not affect abdominal distension (p= not significant); however, age modified the time of distension. A 0.85 cm increase in waist circumference compared to the baseline waist circumference during the hydrogen breath test is a useful parameter for the diagnosis of lactose intolerance in pediatrics. Variations in relation to body mass index and waist circumference did not affect the usefulness of an increased waist circumference, unlike age.

Simplified 13C-urea breath test with a new infrared spectrometer for diagnosis of Helicobacter pylori infection.

PubMed

Chen, Tseng-Shing; Chang, Full-Young; Chen, Pang-Chi; Huang, Thomas W; Ou, Jonathan T; Tsai, Ming-Hung; Wu, Ming-Shiang; Lin, Jaw-Town

2003-11-01

Infrared spectrometry has correlated excellently with mass spectrometry in detecting the ratio of 13CO(2) to 12CO(2) in breath samples. The present study aimed to evaluate the accuracy of the 13C-urea breath test (13C-UBT) using a new model of infrared analyzer. A total of 600 patients who were undergoing upper endoscopy without receiving eradication therapy were entered into the study. Culture, histology, and rapid urease test on biopsies from the antrum and corpus of the stomach were used for the determination of Helicobacter pylori infection. Breath samples were collected before and 20 min after drinking 100 mg 13C-urea in 100 mL water. The optimal cutoff value was determined by the receiver operating characteristic curve. Of the 586 patients who were eligible for analysis, 369 were positive for H. pylori infection, 185 were negative for H. pylori infection, and 32 were indeterminate. When the appropriate cutoff value was set at 3.5 per thousand, a sensitivity of 97.8%, a specificity of 96.8% and an accuracy of 97.5% were obtained using the 13C-UBT. The accuracy of the 13C-UBT decreased when CO(2) concentration in the breath sample was <2%, as compared with > or = 2% (93.6%vs 97.7%), mainly because of a decrease in specificity (81.8%vs 97.7%). There were 2.7% of patients with Delta13CO(2) values that fell between 3.0-4.5 per thousand, in whom the risk of error was 47%. The 13C-UBT performed with infrared spectrometry is a highly sensitive, specific, and non-invasive method for the detection of H. pylori infection. The immediate availability of the test result and technical simplicity make it particularly effective in routine clinical practice.

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

USDA-ARS?s Scientific Manuscript database

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

Pure-rotational spectrometry: a vintage analytical method applied to modern breath analysis.

PubMed

Hrubesh, Lawrence W; Droege, Michael W

2013-09-01

Pure-rotational spectrometry (PRS) is an established method, typically used to study structures and properties of polar gas-phase molecules, including isotopic and isomeric varieties. PRS has also been used as an analytical tool where it is particularly well suited for detecting or monitoring low-molecular-weight species that are found in exhaled breath. PRS is principally notable for its ultra-high spectral resolution which leads to exceptional specificity to identify molecular compounds in complex mixtures. Recent developments using carbon aerogel for pre-concentrating polar molecules from air samples have extended the sensitivity of PRS into the part-per-billion range. In this paper we describe the principles of PRS and show how it may be configured in several different modes for breath analysis. We discuss the pre-concentration concept and demonstrate its use with the PRS analyzer for alcohols and ammonia sampled directly from the breath.

Tidal volume single breath washout of two tracer gases--a practical and promising lung function test.

PubMed

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

2011-03-10

Small airway disease frequently occurs in chronic lung diseases and may cause ventilation inhomogeneity (VI), which can be assessed by washout tests of inert tracer gas. Using two tracer gases with unequal molar mass (MM) and diffusivity increases specificity for VI in different lung zones. Currently washout tests are underutilised due to the time and effort required for measurements. The aim of this study was to develop and validate a simple technique for a new tidal single breath washout test (SBW) of sulfur hexafluoride (SF(6)) and helium (He) using an ultrasonic flowmeter (USFM). The tracer gas mixture contained 5% SF(6) and 26.3% He, had similar total MM as air, and was applied for a single tidal breath in 13 healthy adults. The USFM measured MM, which was then plotted against expired volume. USFM and mass spectrometer signals were compared in six subjects performing three SBW. Repeatability and reproducibility of SBW, i.e., area under the MM curve (AUC), were determined in seven subjects performing three SBW 24 hours apart. USFM reliably measured MM during all SBW tests (n = 60). MM from USFM reflected SF(6) and He washout patterns measured by mass spectrometer. USFM signals were highly associated with mass spectrometer signals, e.g., for MM, linear regression r-squared was 0.98. Intra-subject coefficient of variation of AUC was 6.8%, and coefficient of repeatability was 11.8%. The USFM accurately measured relative changes in SF(6) and He washout. SBW tests were repeatable and reproducible in healthy adults. We have developed a fast, reliable, and straightforward USFM based SBW method, which provides valid information on SF(6) and He washout patterns during tidal breathing.

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

PubMed Central

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

2011-01-01

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

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

... 49 Transportation 1 2011-10-01 2011-10-01 false What is the procedure for an alcohol screening test using an EBT or non-evidential breath ASD? 40.243 Section 40.243 Transportation Office of the...-evidential breath ASD? As the BAT or STT, you must take the following steps: (a) Select, or allow the...

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

... 49 Transportation 1 2010-10-01 2010-10-01 false What is the procedure for an alcohol screening test using an EBT or non-evidential breath ASD? 40.243 Section 40.243 Transportation Office of the...-evidential breath ASD? As the BAT or STT, you must take the following steps: (a) Select, or allow the...

Breath-collection device for delayed breath-alcohol analysis

DOT National Transportation Integrated Search

1980-12-01

The report includes the details of a study to develop, evaluate, and validate a breath collection device (BCD) for delayed breath-alcohol analysis. Primary applications of the BCD include collection of breath-alcohol samples for field surveys or for ...

Clinical research on liver reserve function by 13C-phenylalanine breath test in aged patients with chronic liver diseases

PubMed Central

2010-01-01

Background The objective of this study was to investigate whether the 13C-phenylalanine breath test could be useful for the evaluation of hepatic function in elderly volunteers and patients with chronic hepatitis B and liver cirrhosis. Methods L-[1-13C] phenylalanine was administered orally at a dose of 100 mg to 55 elderly patients with liver cirrhosis, 30 patients with chronic hepatitis B and 38 elderly healthy subjects. The breath test was performed at 8 different time points (0, 10, 20, 30, 45, 60, 90, 120 min) to obtain the values of Delta over baseline, percentage 13CO2 exhalation rate and cumulative excretion (Cum). The relationships of the cumulative excretion with the 13C-%dose/h and blood biochemical parameters were investigated. Results The 13C-%dose/h at 20 min and 30 min combined with the cumulative excretion at 60 min and 120 min correlated with hepatic function tests, serum albumin, hemoglobin, platelet and Child-Pugh score. Prothrombin time, total and direct bilirubin were significantly increased, while serum albumin, hemoglobin and platelet, the cumulative excretion at 60 min and 120 min values decreased by degrees of intensity of the disease in Child-Pugh A, B, and C patients (P < 0.01). Conclusions The 13C-phenylalanine breath test can be used as a non-invasive assay to evaluate hepatic function in elderly patients with liver cirrhosis. The 13C-%dose/h at 20 min, at 30 min and cumulative excretion at 60 min may be the key value for determination at a single time-point. 13C-phenylalanine breath test is safe and helpful in distinguishing different stages of hepatic dysfunction for elderly cirrhosis patients. PMID:20459849

A comparison between lactose breath test and quick test on duodenal biopsies for diagnosing lactase deficiency in patients with self-reported lactose intolerance.

PubMed

Furnari, Manuele; Bonfanti, Daria; Parodi, Andrea; Franzè, Jolanda; Savarino, Edoardo; Bruzzone, Luca; Moscatelli, Alessandro; Di Mario, Francesco; Dulbecco, Pietro; Savarino, Vincenzo

2013-02-01

A lactose breath test (LBT) is usually used to diagnose lactase deficiency, and a lactose quick test (LQT) has been proposed as a new test on duodenal biopsies to detect this disorder. We aimed to assess the diagnostic accuracy of LBT and LQT and their ability to predict the clinical response to a lactose-free diet in patients with self-reported lactose intolerance. Fifty-five patients (age 47 ± 14 y; M/F 15/36) underwent upper gastrointestinal endoscopy and 25g-LBT. Two duodenal biopsies were taken to determine lactase deficiency (normal, mild, or severe) by LQT and to rule out other causes of secondary lactose malabsorption. Patients with a positive LBT and normal LQT also underwent a glucose breath test to exclude small intestinal bacterial overgrowth as a cause of the former result. The severity of gastrointestinal symptoms was measured with a GSS questionnaire, under basal condition and 1 month after a lactose-free diet. Lactose malabsorption was detected in 31/51 patients with LBT and in 37/51 patients with LQT (P = NS). Celiac disease was found in 2 patients. Two LBT+ patients showed a positive glucose breath test for small intestinal bacterial overgrowth. Eight patients had a mild hypolactasia by LQT and a negative LBT, but they had a significant improvement of symptoms after diet. LQT and LBT were concordant in 83% of cases and predicted the response to a lactose-free diet in 98% and 81% of the cases, respectively (P = 0.03). LQT is as sensitive as LBT in detecting lactase deficiency; however, it seems to be more accurate than LBT in predicting the clinical response to a lactose-free diet.

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 asthma...

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

PubMed Central

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

2008-01-01

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

How to breathe when you are short of breath

MedlinePlus

... pursed lip breathing; Hypoxia - pursed lip breathing; Chronic respiratory failure - pursed lip breathing ... et al, eds. Murray and Nadel's Textbook of Respiratory Medicine . 6th ed. Philadelphia, PA: Elsevier Saunders; 2016: ...

Fourier-transformed infrared breath testing after ingestion of technical alcohol.

PubMed

Laakso, Olli; Haapala, Matti; Pennanen, Teemu; Kuitunen, Tapio; Himberg, Jaakko-Juhani

2007-07-01

The study aim was to evaluate the feasibility of a Fourier-transformed infrared (FT-IR) analyzer for out-of-laboratory use by screening the exhalations of inebriated individuals, and to determine analysis quality using common breath components and solvents. Each of the 35 inebriated participants gave an acceptable sample. Because of the metabolism of 2-propanol, the subjects exhaled high concentrations of acetone in addition to ethanol. Other volatile ingredients of technical ethanol products (methyl ethyl ketone, methyl isobutyl ketone, and 2-propanol) were also detected. The lower limits of quantification for the analyzed components ranged from 1.7 to 12 microg/L in simulated breath samples. The bias was +/-2% for ethanol and -11% for methanol. Within-day and between-day coefficients of variation were <1% for ethanol and <4% for methanol. The bias of ethanol and methanol analyses due to coexisting solvents ranged from -0.8 to +2.2% and from -5.6 to +2.9%, respectively. The FT-IR method proved suitable for use outside the laboratory and fulfilled the quality criteria for analysis of solvents in breath.

[13C]Glucose Breath Testing Provides a Noninvasive Measure of Insulin Resistance: Calibration Analyses Against Clamp Studies

PubMed Central

Hussain, Maysa; Jangorbhani, Morteza; Schuette, Sally; Considine, Robert V.; Chisholm, Robin L.

2014-01-01

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

Effect of alcohol consumption on the liver detoxication capacity as measured by [13C]methacetin- and [methyl-13C]methionine-breath tests.

PubMed

Wutzke, Klaus D; Forberger, Anke; Wigger, Marianne

2008-06-01

The aim of this study was to investigate the hepatic microsomal and mitochondrial functions by using the 13CO2-breath test in healthy subjects either before or after the consumption of red wine. Fourteen adults received [13C]methacetin and [methyl-13C]methionine together with a standardised dinner. Expired air samples were taken over 6 h. After a wash-out period, the subjects consumed 0.4 ml ethanol/kg/day together with dinner over a 10-day period. Thereafter, 13C-tracer administration was repeated under identical conditions. The 13CO2-enrichments were measured by isotope ratio mass spectrometry. The mean cumulative percentage 13C-dose recovery (CPDR) after administration of [13C]methacetin and [methyl-13C]methionine either without or with red wine consumption amounted to 38.2+/-6.3 vs. 36.3+/-6.7% (p=0.363) and 9.5+/-3.3 vs. 8.8+/-2.5% (p=0.47), respectively. Moderate alcohol consumption does not induce significant short-term changes of the microsomal and the mitochondrial functions of the human liver in healthy subjects.

Determination of breath acetone in 149 type 2 diabetic patients using a ringdown breath-acetone analyzer.

PubMed

Sun, Meixiu; Chen, Zhuying; Gong, Zhiyong; Zhao, Xiaomeng; Jiang, Chenyu; Yuan, Yuan; Wang, Zhennang; Li, Yingxin; Wang, Chuji

2015-02-01

Over 90% of diabetic patients have Type 2 diabetes. Although an elevated mean breath acetone concentration has been found to exist in Type 1 diabetes (T1D), information on breath acetone in Type 2 diabetes (T2D) has yet to be obtained. In this study, we first used gas chromatography-mass spectrometry (GC-MS) to validate a ringdown breath-acetone analyzer based on the cavity-ringdown-spectroscopy technique, through comparing breath acetone concentrations in the range 0.5-2.5 ppm measured using both methods. The linear fitting of R = 0.99 suggests that the acetone concentrations obtained using both methods are consistent with a largest standard deviation of ±0.4 ppm in the lowest concentration of the range. Next, 620 breath samples from 149 T2D patients and 42 healthy subjects were collected and tested using the breath analyzer. Four breath samples were taken from each subject under each of four different conditions: fasting, 2 h post-breakfast, 2 h post-lunch, and 2 h post-dinner. Simultaneous blood glucose levels were also measured using a standard diabetic-management blood-glucose meter. For the 149 T2D subjects, their exhaled breath acetone concentrations ranged from 0.1 to 19.8 ppm; four different ranges of breath acetone concentration, 0.1-19.8, 0.1-7.1, 0.1-6.3, and 0.1-9.5 ppm, were obtained for the subjects under the four different conditions, respectively. For the 42 healthy subjects, their breath acetone concentration ranged from 0.1 to 2.6 ppm; four different ranges of breath acetone concentration, 0.3-2.6, 0.1-2.6, 0.1-1.7, and 0.3-1.6 ppm, were obtained for the four different conditions. The mean breath acetone concentration of the 149 T2D subjects was determined to be 1.5 ± 1.5 ppm, which was 1.5 times that of 1.0 ± 0.6 ppm for the 42 healthy subjects. No correlation was found between the breath acetone concentration and the blood glucose level of the T2D subjects and the healthy volunteers. This study using a relatively large number of

Afternoon serum-melatonin in sleep disordered breathing.

PubMed

Ulfberg, J; Micic, S; Strøm, J

1998-08-01

To study afternoon serum-melatonin values in patients with sleep disordered breathing. Melatonin has a strong circadian rhythm with high values during the night-time and low values in the afternoon. Sleep disordered breathing may change the circadian rhythm of melatonin which may have diagnostic implications. The Sleep Laboratory, The Department of Internal Medicine, Avesta Hospital, Sweden, and the Department of Anaesthesiology, Glostrup University Hospital, Copenhagen, Denmark. We examined 60 consecutive patients admitted for sleep disordered breathing and 10 healthy non snoring controls. The patients underwent a sleep apnoea screening test having a specificity of 100% for the obstructive sleep apnoea syndrome (OSAS) using a combination of static charge sensitive bed and oximetry. Obstructive sleep apnoea syndrome was found in 49 patients, eight patients had borderline sleep disordered breathing (BSDB) and three patients were excluded due to interfering disease. Patients and controls had an afternoon determination of serum-melatonin. The Epworth Sleepiness Scale was used to score day-time sleepiness. In comparison with normal controls patients suffering from OSAS had significantly higher serum-melatonin levels in the afternoon. However, as a diagnostic test for OSAS in patients with sleep disordered breathing serum-melatonin showed a low sensitivity but a high specificity. The results indicate that breathing disorders during sleep in general affect pineal function. Sleep disordered breathing seems to disturb pineal function. Determination of afternoon serum-melatonin alone or together with a scoring of daytime sleepiness does not identify OSAS-patients in a heterogeneous population of patients complaining of heavy snoring and excessive daytime sleepiness.

Exercise training improves breathing strategy and performance during the six-minute walk test in obese adolescents.

PubMed

Mendelson, Monique; Michallet, Anne-Sophie; Perrin, Claudine; Levy, Patrick; Wuyam, Bernard; Flore, Patrice

2014-08-15

We aimed to examine ventilatory responses during the six-minute walk test in healthy-weight and obese adolescents before and after exercise training. Twenty obese adolescents (OB) (age: 14.5±1.7 years; BMI: 34.0±4.7kg·m(-2)) and 20 age and gender-matched healthy-weight adolescents (HW) (age: 15.5±1.5 years; BMI: 19.9±1.4kg·m(-2)) completed six-minute walk test during which breath-by-breath gas analysis and expiratory flow limitation (expFL) were measured. OB participated in a 12-week exercise-training program. Comparison between HW and OB participants showed lower distance achieved during the 6MWT in OB (-111.0m, 95%CI: -160.1 to 62.0, p<0.05) and exertional breathlessness was greater (+0.78 a.u., 95%CI: 0.091-3.27, p=0.039) when compared with HW. Obese adolescents breathed at lower lung volumes, as evidenced by lower end expiratory and end inspiratory lung volumes during exercise (p<0.05). Prevalence of expFL (8 OB vs 2 HW, p=0.028) and mean expFL (14.9±21.9 vs 5.32±14.6% VT, p=0.043, in OB and HW) were greater in OB. After exercise training, mean increase in the distance achieved during the 6MWT was 64.5 meters (95%CI: 28.1-100.9, p=0.014) and mean decrease in exertional breathlessness was 1.62 (95%CI: 0.47-2.71, p=0.05). Obese adolescents breathed at higher lung volumes, as evidenced by the increase in end inspiratory lung volume from rest to 6-min exercise (9.9±13.4 vs 20.0±13.6%TLC, p<0.05). Improved performance was associated with improved change in end inspiratory lung volume from rest to 6-min exercise (r=0.65, p=0.025). Our results suggest that exercise training can improve breathing strategy during submaximal exercise in obese adolescents and that this increase is associated with greater exercise performance. Copyright © 2014 Elsevier B.V. All rights reserved.

Breath analysis in disease diagnosis: methodological considerations and applications.

PubMed

Lourenço, Célia; Turner, Claire

2014-06-20

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.

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

PubMed

Donaldsson, Snorri; Falk, Markus; Jonsson, Baldvin; Drevhammar, Thomas

2015-01-01

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. 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. 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. 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.

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

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

PubMed

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

2008-05-01

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

Physical and Biological Carbon Isotope Fractionation in Methane During Gas-Push-Pull-Tests

NASA Astrophysics Data System (ADS)

Gonzalez-Gil, G.; Schroth, M. H.; Gomez, K.; Zeyer, J.

2005-12-01

Stable isotope analyses have become a common tool to assess microbially-mediated processes in subsurface environments. We investigated if stable carbon isotope analysis can be used as a tool to complement gas push-pull tests (GPPTs), a novel technique that was recently developed and tested for the in-situ quantification of CH4 oxidation in soils. During a GPPT a gas mixture containing CH4, O2 and nonreactive tracer gases is injected into the soil, where CH4 is oxidized by indigenous microorganisms. Thereafter, a blend of injected gas mixture and soil air is extracted from the same location, and CH4 oxidation is quantified from an analysis of extracted CH4 and tracer gases. To assess the magnitude of physical isotope fractionation due to molecular diffusion during GPPTs, we conducted laboratory experiments in the absence of microbial activity in a 1m-high, 1m-diameter tank filled with dry sand. During the GPPTs' extraction phase, the isotopic composition of methane was analyzed. Results indicated strong carbon isotope fractionation (>20 per mil) during GPPTs. To assess the combined effect of physical and biological isotope fractionation, numerical simulations of GPPTs were conducted in which microbial CH4 isotope fractionation was simulated using first-order rate constants and microbial kinetic isotope fractionation factors previously reported for methane oxidation in landfill environments. Results of these simulations indicated that for small CH4 oxidation rates, overall isotope fractionation in CH4 is dominated by physical fractionation. Conversely, for high CH4 oxidation rates, overall fractionation is dominated by biological fractionation. Thus, CH4 isotope fractionation data alone from a single GPPT cannot be used to assess microbial CH4 oxidation. However, biological fractionation may be quantified if physical fractionation due to diffusion is known. This can be achieved by conducting two sequential GPPTs, with microbial activity being inhibited in the second

Variability in the blood/breath alcohol ratio and implications for evidentiary purposes.

PubMed

Jaffe, Dena H; Siman-Tov, Maya; Gopher, Asher; Peleg, Kobi

2013-09-01

The breath analyzer is an indispensable tool for identifying alcohol levels among drivers. While numerous studies have shown high correlations between blood and breath alcohol concentrations, most are limited by the study design. This study seeks to assess this relationship by minimizing potential measurement bias, document time from alcohol consumption to testing, and adjusting for potential confounders. A blinded study was performed using conditions closely resembling those in the field. The Draeger 7110 MKIII IL breath analyzer was used to assess breath alcohol concentrations (BrAC). Participants were 61 healthy volunteers aged 21-37 years with body mass index ≤30 and no history of alcoholism. A total of 242 valid blood/breath tests were performed in four test sets. The study results showed a high correlation coefficient between BrAC and blood alcohol concentration (BAC) levels (r = 0.983) with high sensitivity (97%) and specificity (93%). This strong association between the breath analyzer and BAC persisted even after adjustment for various stages of alcohol absorption. These results illustrate the high diagnostic sensitivity of the breath analyzer in field-tested conditions. © 2013 American Academy of Forensic Sciences.

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

PubMed

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

2014-09-01

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

Evaluation of portable breath test devices for screening suspected drunken drivers by police in Hennepin County, Minnesota

DOT National Transportation Integrated Search

1974-06-01

This evaluation report examines use in the field of portable breath test (PBT) devices by police in Hennepin County, Minnesota. Thirteen Brog-Warner J2 and J2A-200 "ALERT" devices were deployed by seven enforcement agencies. This report is presented ...

Diagnostic accuracy of level 3 portable sleep tests versus level 1 polysomnography for sleep-disordered breathing: a systematic review and meta-analysis

PubMed Central

El Shayeb, Mohamed; Topfer, Leigh-Ann; Stafinski, Tania; Pawluk, Lawrence; Menon, Devidas

2014-01-01

Background: Greater awareness of sleep-disordered breathing and rising obesity rates have fueled demand for sleep studies. Sleep testing using level 3 portable devices may expedite diagnosis and reduce the costs associated with level 1 in-laboratory polysomnography. We sought to assess the diagnostic accuracy of level 3 testing compared with level 1 testing and to identify the appropriate patient population for each test. Methods: We conducted a systematic review and meta-analysis of comparative studies of level 3 versus level 1 sleep tests in adults with suspected sleep-disordered breathing. We searched 3 research databases and grey literature sources for studies that reported on diagnostic accuracy parameters or disease management after diagnosis. Two reviewers screened the search results, selected potentially relevant studies and extracted data. We used a bivariate mixed-effects binary regression model to estimate summary diagnostic accuracy parameters. Results: We included 59 studies involving a total of 5026 evaluable patients (mostly patients suspected of having obstructive sleep apnea). Of these, 19 studies were included in the meta-analysis. The estimated area under the receiver operating characteristics curve was high, ranging between 0.85 and 0.99 across different levels of disease severity. Summary sensitivity ranged between 0.79 and 0.97, and summary specificity ranged between 0.60 and 0.93 across different apnea–hypopnea cut-offs. We saw no significant difference in the clinical management parameters between patients who underwent either test to receive their diagnosis. Interpretation: Level 3 portable devices showed good diagnostic performance compared with level 1 sleep tests in adult patients with a high pretest probability of moderate to severe obstructive sleep apnea and no unstable comorbidities. For patients suspected of having other types of sleep-disordered breathing or sleep disorders not related to breathing, level 1 testing remains the

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

13CO2 breath test to measure the hydrolysis of various starch formulations in healthy subjects.

PubMed Central

Hiele, M; Ghoos, Y; Rutgeerts, P; Vantrappen, G; de Buyser, K

1990-01-01

13CO2 starch breath test was used to study the effect of physicochemical characteristics of starch digestion. As starch is hydrolysed to glucose, which is subsequently oxidised to CO2, differences in 13CO2 excretion after ingestion of different starch products must be caused by differences in hydrolysis rate. To study the effect of the degree of chain branching, waxy starch, containing 98% amylopectin, was compared with high amylose starch, containing 30% amylopectin, and normal crystalline starch, containing 74% amylopectin. The effect of the extent of gelatinisation was studied by comparing extruded starch and crystalline starch. Finally, the possible inhibitory effect of adding wheat fibre to extruded starch on the hydrolysis rate was studied. The 13CO2 excretion from two to four hours after intake of crystalline starch was significantly lower than that of extruded starch. Waxy starch was hydrolysed much faster than high amylose starch, but there was no significant difference between waxy starch and normal crystalline starch. Addition of wheat fibre did not influence the hydrolysis rate. The 13CO2 starch breath test is an attractive test for the study of factors affecting carbohydrate assimilation. PMID:2107133

Effect of Time-of-Flight Information on PET/MR Reconstruction Artifacts: Comparison of Free-breathing versus Breath-hold MR-based Attenuation Correction.

PubMed

Delso, Gaspar; Khalighi, Mohammed; Ter Voert, Edwin; Barbosa, Felipe; Sekine, Tetsuro; Hüllner, Martin; Veit-Haibach, Patrick

2017-01-01

Purpose To evaluate the magnitude and anatomic extent of the artifacts introduced on positron emission tomographic (PET)/magnetic resonance (MR) images by respiratory state mismatch in the attenuation map. Materials and Methods The method was tested on 14 patients referred for an oncologic examination who underwent PET/MR imaging. The acquisition included standard PET and MR series for each patient, and an additional attenuation correction series was acquired by using breath hold. PET data were reconstructed with and without time-of-flight (TOF) information, first by using the standard free-breathing attenuation map and then again by using the additional breath-hold map. Two-tailed paired t testing and linear regression with 0 intercept was performed on TOF versus non-TOF and free-breathing versus breath-hold data for all detected lesions. Results Fluorodeoxyglucose-avid lesions were found in eight of the 14 patients included in the study. The uptake differences (maximum standardized uptake values) between PET reconstructions with free-breathing versus breath-hold attenuation ranged, for non-TOF reconstructions, from -18% to 26%. The corresponding TOF reconstructions yielded differences from -15% to 18%. Conclusion TOF information was shown to reduce the artifacts caused at PET/MR by respiratory mismatch between emission and attenuation data. © RSNA, 2016 Online supplemental material is available for this article.

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

Use of warrants for breath test refusal : case studies

DOT National Transportation Integrated Search

2007-10-01

This study investigated the use of warrants to obtain blood samples from drivers arrested for alcohol-impaired driving and who refuse to provide breath samples when requested to do so by law enforcement officers. Case studies were conducted in four S...

Air sampling unit for breath analyzers

NASA Astrophysics Data System (ADS)

Szabra, Dariusz; Prokopiuk, Artur; Mikołajczyk, Janusz; Ligor, Tomasz; Buszewski, Bogusław; Bielecki, Zbigniew

2017-11-01

The paper presents a portable breath sampling unit (BSU) for human breath analyzers. The developed unit can be used to probe air from the upper airway and alveolar for clinical and science studies. The BSU is able to operate as a patient interface device for most types of breath analyzers. Its main task is to separate and to collect the selected phases of the exhaled air. To monitor the so-called I, II, or III phase and to identify the airflow from the upper and lower parts of the human respiratory system, the unit performs measurements of the exhaled CO2 (ECO2) in the concentration range of 0%-20% (0-150 mm Hg). It can work in both on-line and off-line modes according to American Thoracic Society/European Respiratory Society standards. A Tedlar bag with a volume of 5 dm3 is mounted as a BSU sample container. This volume allows us to collect ca. 1-25 selected breath phases. At the user panel, each step of the unit operation is visualized by LED indicators. This helps us to regulate the natural breathing cycle of the patient. There is also an operator's panel to ensure monitoring and configuration setup of the unit parameters. The operation of the breath sampling unit was preliminarily verified using the gas chromatography/mass spectrometry (GC/MS) laboratory setup. At this setup, volatile organic compounds were extracted by solid phase microextraction. The tests were performed by the comparison of GC/MS signals from both exhaled nitric oxide and isoprene analyses for three breath phases. The functionality of the unit was proven because there was an observed increase in the signal level in the case of the III phase (approximately 40%). The described work made it possible to construct a prototype of a very efficient breath sampling unit dedicated to breath sample analyzers.

The likelihood of acetone interference in breath alcohol measurement

DOT National Transportation Integrated Search

1985-09-01

This report discusses the significance of possible interference of acetone in breath alcohol testing. The following dimensions were considered: 1) what levels of acetone concentration may appear on the breath; 2) what levels of acetone concentration ...

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

Four-sample lactose hydrogen breath test for diagnosis of lactose malabsorption in irritable bowel syndrome patients with diarrhea.

PubMed

Yang, Jian-Feng; Fox, Mark; Chu, Hua; Zheng, Xia; Long, Yan-Qin; Pohl, Daniel; Fried, Michael; Dai, Ning

2015-06-28

To validate 4-sample lactose hydrogen breath testing (4SLHBT) compared to standard 13-sample LHBT in the clinical setting. 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. 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. 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.

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.

Hepatobiliary MRI: Signal intensity based assessment of liver function correlated to 13C-Methacetin breath test.

PubMed

Haimerl, Michael; Probst, Ute; Poelsterl, Stefanie; Beyer, Lukas; Fellner, Claudia; Selgrad, Michael; Hornung, Matthias; Stroszczynski, Christian; Wiggermann, Philipp

2018-06-13

Gadoxetic acid (Gd-EOB-DTPA) is a paramagnetic MRI contrast agent with raising popularity and has been used for evaluation of imaging-based liver function in recent years. In order to verify whether liver function as determined by real-time breath analysis using the intravenous administration of 13 C-methacetin can be estimated quantitatively from Gd-EOB-DTPA-enhanced MRI using signal intensity (SI) values. 110 patients underwent Gd-EOB-DTPA-enhanced 3-T MRI and, for the evaluation of liver function, a 13 C-methacetin breath test ( 13 C-MBT). SI values from before (SI pre ) and 20 min after (SI post ) contrast media injection were acquired by T1-weighted volume-interpolated breath-hold examination (VIBE) sequences with fat suppression. The relative enhancement (RE) between the plain and contrast-enhanced SI values was calculated and evaluated in a correlation analysis of 13 C-MBT values to SI post and RE to obtain a SI-based estimation of 13 C-MBT values. The simple regression model showed a log-linear correlation of 13 C-MBT values with SI post and RE (p < 0.001). Stratified by 3 different categories of 13 C-MBT readouts, there was a constant significant decrease in both SI post (p ≤ 0.002) and RE (p ≤ 0.033) with increasing liver disease progression as assessed by the 13 C-MBT. Liver function as determined using real-time 13 C-methacetin breath analysis can be estimated quantitatively from Gd-EOB-DTPA-enhanced MRI using SI-based indices.

[Breath alcohol test in construction sites in the Province of Belluno: a campaign in favour of health promotion and surveillance and against drinking].

PubMed

Marcolina, Daniela; De Marzo, Nicoletta; Riccio, Maria Teresa

2011-01-01

Health impairment due to alcohol use and abuse is well known, in terms of relationship with traffic accidents and work accidents. In Italy almost 10 per cent of accidents at work involve intoxicated people injuring themselves and innocent victims. Alcohol abuse is a factor involved in determining severe accidents in the construction industry and epidemiological studies demonstrated a relationship between an elevated alcohol use and severity of accidents. Since in the Province of Belluno alcohol consumption may be elevated also at work, the two Occupational Health Units (SPISAL) in the province organized a campaign of information and surveillance against alcohol consumption at work in the construction industry. This report shows the campaign results, mainly in terms of breath alcohol tests performed in construction workers. After an extensive information campaign we inspected 50 sites, where 105 construction companies were at work, and tested 294 workers by breath alcohol test. No-one refused the test. Only 2.7% construction workers were positive for the breath alcohol test, and the levels were not elevated. This study shows that the construction workers in Belluno Province are responsible drinkers and are well aware of the policy of prohibition of alcohol consumption at work.

Evaluation of the 13C-octanoate breath test as a surrogate marker of liver damage in animal models.

PubMed

Shalev, Tamar; Aeed, Hussein; Sorin, Vladimir; Shahmurov, Mark; Didkovsky, Elena; Ilan, Yaron; Avni, Yona; Shirin, Haim

2010-06-01

Octanoate (also known as sodium octanoate), a medium-chain fatty acid metabolized in the liver, is a potential substrate for non-invasive breath testing of hepatic mitochondrial beta-oxidation. We evaluated the 13C-octanoate breath test (OBT) for assessing injury in acute hepatitis and two rat models of liver cirrhosis, first testing octanoate absorption (per os or intraperitoneally (i.p.)) in normal rats. We then induced acute hepatitis with thioacetamide (300 mg/kg/i.p., 24-h intervals). Liver injury end points were serum aminotransferase levels and 13C-OBT (24 and 48 h following initial injection). Thioacetamide (200 mg/kg/i.p., twice per week, 12 weeks) was used to induce liver cirrhosis. OBT and liver histological assessment were performed every 4 weeks. Bile duct ligation (BDL) was used to induce cholestatic liver injury. We completed breath tests with 13C-OBT and 13C-methacetin (MBID), liver biochemistry, and liver histology in BDL and sham-operated rats (baseline, 6, 14, 20 days post-BDL). Octanoate absorbs well by either route. Peak amplitudes and cumulative percentage dose recovered at 30 and 60 min (CPDR30/60), but not peak time, correlated with acute hepatitis. Fibrosis stage 3 at week 8 significantly correlated with each OBT parameter. Cholestatic liver injury (serum bilirubin, ALP, gamma-GT, liver histology) was associated with significant suppression of the maximal peak values and CPDR30/60, respectively (P<0.05),using MBID but not 13C-octanoate. OBT is sensitive for potentially evaluating liver function in rat models of acute hepatitis and thioacetamide-induced liver cirrhosis but not in cholestatic liver injury. The MBID test may be better for evaluation of cholestatic liver disease in this model.

Positive or negative fructose breath test results do not predict response to fructose restricted diet in children with recurrent abdominal pain: results from a prospective randomized trial.

PubMed

Wirth, S; Klodt, C; Wintermeyer, P; Berrang, J; Hensel, K; Langer, T; Heusch, A

2014-09-01

To perform a prospective, blinded, randomized interventional trial in patients with recurrent abdominal pain. The primary endpoint was to determine the abdominal pain intensity after 2 weeks of fructose restricted diet. Secondary endpoints were changes of pain frequency and a secondary symptom score (SSS). 103 individuals with recurrent abdominal pain for more than 3 months were randomized. 51 patients were allocated to group A (diet) and 52 to group B (no diet). 2 weeks later the patients underwent hydrogen breath test and were assigned to the test positive or negative group to identify patients with fructose malabsorption. 2 weeks after intervention the pain score decreased significantly from a median 5.5 in group A to 4 and did not change significantly in group B (5.3 to 5). In group A both patients with positive and negative breath tests had a significant lower pain score (-2 and -1.75, respectively). Frequency of abdominal pain decreased in both groups but without significant difference, SSS improved only in group A from median 6 to 3.5. Positive breath test was no predicting factor, neither was abdominal pain during the test. Fructose restricted diet in children and adolescents with recurrent abdominal pain may be of benefit to improve both abdominal pain symptoms and other secondary symptoms. Since a negative breath test result does not exclude a positive response to fructose restriction, the hydrogen breath test does not seem to be the appropriate diagnostic mean to predict the response to the diet. © Georg Thieme Verlag KG Stuttgart · New York.

Molecular hydrogen in human breath: a new strategy for selectively diagnosing peptic ulcer disease, non-ulcerous dyspepsia and Helicobacter pylori infection.

PubMed

Maity, Abhijit; Pal, Mithun; Maithani, Sanchi; Ghosh, Barnali; Chaudhuri, Sujit; Pradhan, Manik

2016-07-22

The gastric pathogen Helicobacter pylori utilizes molecular hydrogen (H2) as a respiratory substrate during colonization in the gastric mucosa. However, the link between molecular H2 and the pathogenesis of peptic-ulcer disease (PUD) and non-ulcerous dyspepsia (NUD) by the enzymatic activity of H. pylori still remains mostly unknown. Here we provide evidence that breath H2 excretion profiles are distinctly altered by the enzymatic activity of H. pylori for individuals with NUD and PUD. We subsequently unravelled the potential molecular mechanisms responsible for the alteration of H2 in exhaled breath in association with peptic ulcers, encompassing both gastric and duodenal ulcers, along with NUD. We also established that carbon-isotopic fractionations in the acid-mediated bacterial environment regulated by bacterial urease activity cannot discriminate the actual disease state i.e. whether it is peptic ulcer or NUD. However, our findings illuminate the unusual molecular H2 in breath that can track the precise evolution of PUD and NUD, even after the eradication of H. pylori infection. This deepens our understanding of the pathophysiology of PUD and NUD, reveals non-invasively the actual disease state in real-time and thus offers a novel and robust new-generation strategy for treating peptic-ulcer disease together with non-ulcer related complications even when the existing (13)C-urea breath test ((13)C-UBT) fails to diagnose.

Human breath metabolomics using an optimized noninvasive exhaled breath condensate sampler

PubMed Central

Zamuruyev, Konstantin O.; Aksenov, Alexander A.; Pasamontes, Alberto; Brown, Joshua F.; Pettit, Dayna R.; Foutouhi, Soraya; Weimer, Bart C.; Schivo, Michael; Kenyon, Nicholas J.; Delplanque, Jean-Pierre; Davis, Cristina E.

2017-01-01

Exhaled breath condensate (EBC) analysis is a developing field with tremendous promise to advance personalized, non-invasive health diagnostics as new analytical instrumentation platforms and detection methods are developed. Multiple commercially-available and researcher-built experimental samplers are reported in the literature. However, there is very limited information available to determine an effective breath sampling approach, especially regarding the dependence of breath sample metabolomic content on the collection device design and sampling methodology. This lack of an optimal standard procedure results in a range of reported results that are sometimes contradictory. Here, we present a design of a portable human EBC sampler optimized for collection and preservation of the rich metabolomic content of breath. The performance of the engineered device is compared to two commercially available breath collection devices: the RTube™ and TurboDECCS. A number of design and performance parameters are considered, including: condenser temperature stability during sampling, collection efficiency, condenser material choice, and saliva contamination in the collected breath samples. The significance of the biological content of breath samples, collected with each device, is evaluated with a set of mass spectrometry methods and was the primary factor for evaluating device performance. The design includes an adjustable mass-size threshold for aerodynamic filtering of saliva droplets from the breath flow. Engineering an inexpensive device that allows efficient collection of metalomic-rich breath samples is intended to aid further advancement in the field of breath analysis for non-invasive health diagnostic. EBC sampling from human volunteers was performed under UC Davis IRB protocol 63701-3 (09/30/2014-07/07/2017). PMID:28004639

Control of gill ventilation and air-breathing in the bowfin amia calva

PubMed

Hedrick; Jones

1999-01-01

The purpose of this study was to investigate the roles of branchial and gas bladder reflex pathways in the control of gill ventilation and air-breathing in the bowfin Amia calva. We have previously determined that bowfin use two distinct air-breathing mechanisms to ventilate the gas bladder: type I air breaths are characterized by exhalation followed by inhalation, are stimulated by aquatic or aerial hypoxia and appear to regulate O2 gas exchange; type II air breaths are characterized by inhalation alone and possibly regulate gas bladder volume and buoyancy. In the present study, we test the hypotheses (1) that gill ventilation and type I air breaths are controlled by O2-sensitive chemoreceptors located in the branchial region, and (2) that type II air breaths are controlled by gas bladder mechanosensitive stretch receptors. Hypothesis 1 was tested by examining the effects of partial or complete branchial denervation of cranial nerves IX and X to the gill arches on gill ventilation frequency (fg) and the proportion of type I air breaths during normoxia and hypoxia; hypothesis II was tested by gas bladder inflation and deflation. Following complete bilateral branchial denervation, fg did not differ from that of sham-operated control fish; in addition, fg was not significantly affected by aquatic hypoxia in sham-operated or denervated fish. In sham-operated fish, aquatic hypoxia significantly increased overall air-breathing frequency (fab) and the percentage of type I breaths. In fish with complete IX-X branchial denervation, fab was also significantly increased during aquatic hypoxia, but there were equal percentages of type I and type II air breaths. Branchial denervation did not affect the frequency of type I air breaths during aquatic hypoxia. Gas bladder deflation via an indwelling catheter resulted in type II breaths almost exclusively; furthermore, fab was significantly correlated with the volume removed from the gas bladder, suggesting a volume

Estimation of gastric pH in cynomolgus monkeys, rats, and dogs using [(13)C]-calcium carbonate breath test.

PubMed

Tobita, Kazuki; Inada, Makoto; Sato, Asuka; Sudoh, Kimiyoshi; Sato, Hitoshi

2016-09-01

The determination of gastric pH is important for the confirmation of efficacy of anti-secretory drugs. However, current methods for measurement of gastric pH provide significant stress to animals and humans. The objective of this study is to establish an easy and reliable gastric pH measurement method by determining (13)CO2 concentration in expired air of monkeys, dogs, and rats after oral administration of Ca(13)CO3. A correlation of (13)CO2 concentration determined by a Ca(13)CO3 breath test with gastric pH just before Ca(13)CO3 administration was analyzed in the 3 animal species. The equations and contribution ratios of regression line were calculated from logarithmic (13)CO2 concentrations at 15min after administration of Ca(13)CO3 using the linear regression analysis. The (13)CO2 concentration in the Ca(13)CO3 breath test was well correlated with the gastric pH just before Ca(13)CO3 administration in the 3 animal species (r=-0.977 to -0.952). The equations of regression line between the (13)CO2 concentration and the gastric pH in each animal species showed good contribution ratios (R(2)≥0.89). The Ca(13)CO3 breath test is an informative tool to estimate gastric pH in animals and will be applicable as a new noninvasive tool for patients with GERD/PPI-resistant symptoms. Copyright © 2016 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

Portable Breathing Assembly

NASA Image and Video Library

2017-06-12

In the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, Jacobs Test and Operations Support Contract, or TOSC, technicians fill portable breathing apparatuses, or PBAS. The PBAs are to be use on board the International Space Staton to provide astronauts with breathable air in the event of a fire or other emergency situation.

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

PubMed

Rosias, P P; Robroeks, C M; Niemarkt, H J; Kester, A D; Vernooy, J H; Suykerbuyk, J; Teunissen, J; Heynens, J; Hendriks, H J; Jöbsis, Q; Dompeling, E

2006-11-01

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

Breath-hold times in air compared to breath-hold times during cold water immersions.

PubMed

Taber, Michael J; MacKinnon, Scott N; Power, Jonathan; Walker, Robert

2015-02-01

Given the effects of cold water immersion on breath-hold (BH) capabilities, a practical training exercise was developed for military/paramilitary personnel completing a helicopter underwater egress training (HUET) program. The exercise was designed to provide firsth and experience of the effects of cold water exposure on BH time. After completing the required HUET, 47 subjects completed two BH testing sessions as well as a short questionnaire. The first BH was completed while standing on the pool deck. The second BH was completed while fully immersed (face down) in 2-3°C water. There were 40 of the volunteers who also breathed from an emergency breathing system (EBS) while in the cold water. Results demonstrated that BH capabilities in cold water were significantly lower than those in ambient air. A significant correlation was also found between BH in air and the difference in cold water vs. air BH capabilities, which suggests that subjects who can hold their breath the longest in air experienced the greatest decrease in BH when immersed. Results indicate that 92% of the subjects reported that the practical cold water immersion exercise had a high value. Finally, 58% of those who used the EBS reported that it was harder to breathe in cold water than while in the training pool (approximately 22°C). The BH times for this group were similar to those reported in previous cold water immersion studies. Based on the questionnaire results, it is possible, when carefully applied, to include a practical cold water immersion exercise into existing HUET programs.

Chemoresponsiveness and breath physiology in anosmia.

PubMed

Mazzatenta, Andrea; Pokorski, Mieczyslaw; Montinaro, Danilo; Di Giulio, Camillo

2015-01-01

Anosmia is a model to study the interaction among chemoreception systems. In the head injury, the traumatic irreversible anosmia caused by damage to olfactory nerve fibers and brain regions is of enviable research interest. In this study, psychophysiological tests for a comprehensive assessment of olfactory function were utilized to investigate anosmia, together with a new technique based on the breath real-time monitoring of volatile organic compounds (VOCs). We applied the breath and VOCs analysis to investigate chemoresponsiveness in the long-term irreversible post-traumatic anosmia.

Bayesian modelling of lung function data from multiple-breath washout tests.

PubMed

Mahar, Robert K; Carlin, John B; Ranganathan, Sarath; Ponsonby, Anne-Louise; Vuillermin, Peter; Vukcevic, Damjan

2018-05-30

Paediatric respiratory researchers have widely adopted the multiple-breath washout (MBW) test because it allows assessment of lung function in unsedated infants and is well suited to longitudinal studies of lung development and disease. However, a substantial proportion of MBW tests in infants fail current acceptability criteria. We hypothesised that a model-based approach to analysing the data, in place of traditional simple empirical summaries, would enable more efficient use of these tests. We therefore developed a novel statistical model for infant MBW data and applied it to 1197 tests from 432 individuals from a large birth cohort study. We focus on Bayesian estimation of the lung clearance index, the most commonly used summary of lung function from MBW tests. Our results show that the model provides an excellent fit to the data and shed further light on statistical properties of the standard empirical approach. Furthermore, the modelling approach enables the lung clearance index to be estimated by using tests with different degrees of completeness, something not possible with the standard approach. Our model therefore allows previously unused data to be used rather than discarded, as well as routine use of shorter tests without significant loss of precision. Beyond our specific application, our work illustrates a number of important aspects of Bayesian modelling in practice, such as the importance of hierarchical specifications to account for repeated measurements and the value of model checking via posterior predictive distributions. Copyright © 2018 John Wiley & Sons, Ltd.

Exhaled breath temperature in children: reproducibility and influencing factors.

PubMed

Vermeulen, S; Barreto, M; La Penna, F; Prete, A; Martella, S; Biagiarelli, F; Villa, M P

2014-09-01

This study will investigate the reproducibility and influencing factors of exhaled breath temperature measured with the tidal breathing technique in asthmatic patients and healthy children. Exhaled breath temperature, fractional exhaled nitric oxide, and spirometry were assessed in 124 children (63 healthy and 61 asthmatic), aged 11.2 ± 2.5 year, M/F 73/51. A modified version of the American Thoracic Society questionnaire on the child's present and past respiratory history was obtained from parents. Parents were also asked to provide detailed information on their child's medication use during the previous 4 weeks. Ear temperature, ambient temperature, and relative-ambient humidity were also recorded. Exhaled breath temperature measurements were highly reproducible; the second measurement was higher than the first measurement, consistent with a test-retest situation. In 13 subjects, between-session within-day reproducibility of exhaled breath temperature was still high. Exhaled breath temperature increased with age and relative-ambient humidity. Exhaled breath temperature was comparable in healthy and asthmatic children; when adjusted for potential confounders (i.e. ambient conditions and subject characteristics), thermal values of asthmatic patients exceeded those of the healthy children by 1.1 °C. Normalized exhaled breath temperature, by subtracting ambient temperature, was lower in asthmatic patients treated with inhaled corticosteroids than in those who were corticosteroid-naive. Measurements of exhaled breath temperature are highly reproducible, yet influenced by several factors. Corrected values, i.e. normalized exhaled breath temperature, could help us to assess the effect of therapy with inhaled corticosteroids. More studies are needed to improve the usefulness of the exhaled breath temperature measured with the tidal breathing technique in children.

Human breath metabolomics using an optimized non-invasive exhaled breath condensate sampler.

PubMed

Zamuruyev, Konstantin O; Aksenov, Alexander A; Pasamontes, Alberto; Brown, Joshua F; Pettit, Dayna R; Foutouhi, Soraya; Weimer, Bart C; Schivo, Michael; Kenyon, Nicholas J; Delplanque, Jean-Pierre; Davis, Cristina E

2016-12-22

Exhaled breath condensate (EBC) analysis is a developing field with tremendous promise to advance personalized, non-invasive health diagnostics as new analytical instrumentation platforms and detection methods are developed. Multiple commercially-available and researcher-built experimental samplers are reported in the literature. However, there is very limited information available to determine an effective breath sampling approach, especially regarding the dependence of breath sample metabolomic content on the collection device design and sampling methodology. This lack of an optimal standard procedure results in a range of reported results that are sometimes contradictory. Here, we present a design of a portable human EBC sampler optimized for collection and preservation of the rich metabolomic content of breath. The performance of the engineered device is compared to two commercially available breath collection devices: the RTube ™ and TurboDECCS. A number of design and performance parameters are considered, including: condenser temperature stability during sampling, collection efficiency, condenser material choice, and saliva contamination in the collected breath samples. The significance of the biological content of breath samples, collected with each device, is evaluated with a set of mass spectrometry methods and was the primary factor for evaluating device performance. The design includes an adjustable mass-size threshold for aerodynamic filtering of saliva droplets from the breath flow. Engineering an inexpensive device that allows efficient collection of metalomic-rich breath samples is intended to aid further advancement in the field of breath analysis for non-invasive health diagnostic. EBC sampling from human volunteers was performed under UC Davis IRB protocol 63701-3 (09/30/2014-07/07/2017).

Breath stacking in children with neuromuscular disorders.

PubMed

Jenkins, H M; Stocki, A; Kriellaars, D; Pasterkamp, H

2014-06-01

Respiratory muscle weakness in neuromuscular disorders (NMD) can lead to shallow breathing and respiratory insufficiency over time. Children with NMD often cannot perform maneuvers to recruit lung volume. In adults, breath stacking with a mask and one-way valve can achieve significantly increased lung volumes. To evaluate involuntary breath stacking (IBS) in NMD, we studied 23 children of whom 15 were cognitively aware and able to communicate verbally. For IBS, a one-way valve and pneumotachograph were attached to a face mask. Tidal volumes (Vt) and minute ventilation (VE ) were calculated from airflow over 30 sec before and after 15 sec of expiratory valve closure. Six cooperative male subjects with Duchenne muscular dystrophy (DMD) participated in a subsequent comparison of IBS with voluntary breath stacking (VBS) and supported breath stacking (SBS). The average Vt in those studied with IBS was 277 ml (range 29-598 ml). The average increase in volume by stacking was 599 ml (range -140 to 2,916 ml) above Vt . The average number of stacked breaths was 4.5 (range 0-17). VE increased on average by 18% after stacking (P < 0.05, paired t-test). Oxygen saturation did not change after stacking. Four of the 23 children did not breath stack. Compared to IBS, VBS achieved similar volumes in the six subjects with DMD but SBS was more successful in those with greatest muscle weakness. IBS may achieve breath volumes of approximately three times Vt and may be particularly useful in non-cooperative subjects with milder degrees of respiratory muscle weakness. © 2013 Wiley Periodicals, Inc.

Right recumbent position on gastric emptying of water evidenced by 13C breath testing

PubMed Central

Sanaka, Masaki; Urita, Yoshihisa; Yamamoto, Takatsugu; Shirai, Tsuguru; Kimura, Satoshi; Aoyagi, Hitoshi; Kuyama, Yasushi

2013-01-01

AIM: To compare the impact of the right recumbent position with the sitting position on gastric emptying of water. METHODS: In eight healthy male volunteers, the 13C acetate breath test was performed twice to assess gastric emptying of 100 mL tap water. Subjects were seated in one test and lying on their right side in the other. In both positions, pulmonary 13CO2 exhalation curves were obtained by plotting breath data against time. Percent gastric retention curves were created by analyzing data using the Wagner-Nelson protocol. RESULTS: No significant posture effect was found in pulmonary 13CO2 output curves (P = 0.2150), whereas a significant effect was seen in gastric retention curves (P = 0.0315). The percent retention values at 10 min and 15 min were significantly smaller when subjects were in the right recumbent position compared with the seated position (P < 0.05). Our results verified the accelerating effect of the right recumbent position on gastric emptying of non-nutritive solutions. Concerning clinical implications, this study suggests that placing patients with acute pain on their right side after oral administration of analgesic drugs in solution is justified as an effective practice for rapid pain relief. For patients with gastrointestinal reflux symptoms, sleeping in the right recumbent position may reduce nocturnal symptoms, as delayed gastric emptying can cause reflux symptoms. CONCLUSION: Gastric emptying of water occurs more quickly when a subject lies on the right side compared with sitting. PMID:23372358

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.

Patients' experiences of breathing retraining for asthma: a qualitative process analysis of participants in the intervention arms of the BREATHE trial.

PubMed

Arden-Close, Emily; Yardley, Lucy; Kirby, Sarah; Thomas, Mike; Bruton, Anne

2017-10-05

, interviewed 16 people about their experiences in a trial that tested breathing retraining exercises delivered by DVD or face-to-face sessions with a respiratory physiotherapist. Overwhelmingly, trial participants reported that breathing retraining sessions gave them greater control over their symptoms, helped them relax, improved their quality of life and reduced the need for medications. Some participants who received DVD instruction said they had trouble mastering the techniques, and many in both groups found it hard to find time to practice the exercises. Overall, however, patients were positive about the experience. The authors conclude that breathing exercises are likely to be a well-received method of asthma management.

Residual gas analyzer mass spectrometry for human breath analysis: a new tool for the non-invasive diagnosis of Helicobacter pylori infection.

PubMed

Maity, Abhijit; Banik, Gourab D; Ghosh, Chiranjit; Som, Suman; Chaudhuri, Sujit; Daschakraborty, Sunil B; Ghosh, Shibendu; Ghosh, Barnali; Raychaudhuri, Arup K; Pradhan, Manik

2014-03-01

A residual gas analyzer (RGA) coupled with a high vacuum chamber is described for the non-invasive diagnosis of the Helicobacter pylori (H. pylori) infection through ¹³C-urea breath analysis. The present RGA-based mass spectrometry (MS) method is capable of measuring high-precision ¹³CO₂ isotope enrichments in exhaled breath samples from individuals harboring the H. pylori infection. The system exhibited 100% diagnostic sensitivity, and 93% specificity alongside positive and negative predictive values of 95% and 100%, respectively, compared with invasive endoscopy-based biopsy tests. A statistically sound diagnostic cut-off value for the presence of H. pylori was determined to be 3.0‰ using a receiver operating characteristic curve analysis. The diagnostic accuracy and validity of the results are also supported by optical off-axis integrated cavity output spectroscopy measurements. The δ¹³(DOB)C‰ values of both methods correlated well (R² = 0.9973 at 30 min). The RGA-based instrumental setup described here is simple, robust, easy-to-use and more portable and cost-effective compared to all other currently available detection methods, thus making it a new point-of-care medical diagnostic tool for the purpose of large-scale screening of the H. pylori infection in real time. The RGA-MS technique should have broad applicability for ¹³C-breath tests in a wide range of biomedical research and clinical diagnostics for many other diseases and metabolic disorders.

Prediction of breast cancer risk with volatile biomarkers in breath.

PubMed

Phillips, Michael; Cataneo, Renee N; Cruz-Ramos, Jose Alfonso; Huston, Jan; Ornelas, Omar; Pappas, Nadine; Pathak, Sonali

2018-03-23

Human breath contains volatile organic compounds (VOCs) that are biomarkers of breast cancer. We investigated the positive and negative predictive values (PPV and NPV) of breath VOC biomarkers as indicators of breast cancer risk. We employed ultra-clean breath collection balloons to collect breath samples from 54 women with biopsy-proven breast cancer and 124 cancer-free controls. Breath VOCs were analyzed with gas chromatography (GC) combined with either mass spectrometry (GC MS) or surface acoustic wave detection (GC SAW). Chromatograms were randomly assigned to a training set or a validation set. Monte Carlo analysis identified significant breath VOC biomarkers of breast cancer in the training set, and these biomarkers were incorporated into a multivariate algorithm to predict disease in the validation set. In the unsplit dataset, the predictive algorithms generated discriminant function (DF) values that varied with sensitivity, specificity, PPV and NPV. Using GC MS, test accuracy = 90% (area under curve of receiver operating characteristic in unsplit dataset) and cross-validated accuracy = 77%. Using GC SAW, test accuracy = 86% and cross-validated accuracy = 74%. With both assays, a low DF value was associated with a low risk of breast cancer (NPV > 99.9%). A high DF value was associated with a high risk of breast cancer and PPV rising to 100%. Analysis of breath VOC samples collected with ultra-clean balloons detected biomarkers that accurately predicted risk of breast cancer.

Testing the Late-Veneer hypothesis with selenium isotopes

NASA Astrophysics Data System (ADS)

Labidi, J.; Koenig, S.; Bennett, N.; Kurzawa, T.; Aierken, E.; Shahar, A.; Schoenberg, R.

2016-12-01

Selenium (Se) is a siderophile element displaying an excess abundance in Earth's mantle compared to experimental predictions [1], which may be attributed to the Late-Veneer. As Se is also volatile, testing the late-veneer addition of Se can constrain the origin of other volatile elements on Earth. Here we combine high-precision Se isotope measurements of metal-silicate partitioning experiments and chondrites to assess whether planetary differentiation could leave a measurable Se isotopic signature on planetary mantles. We performed Se isotopic measurements of 5 metal-silicate partitioning experiments and 20 chondrites of all major classes. Experiments were conducted at 1 GPa and 1650 C for 1 to 4 hours using the piston-cylinder apparatus at Carnegie's Geophysical Laboratory. After wet chemistry, data were obtained on a ThermoFisher Scientific™ NeptunePlus MC-ICP-MS at the University of Tübingen with a 74Se/77Se double spike technique. δ82/76Se values are given relative to NIST SRM-3149 and the external reproducibility calculated from duplicate meteorite analyses is ≤ 0.1‰ (2 s.d.). Chondrites vary over a 0.8‰ range of δ82/76Se values. CIs and CMs show evidence for heavier 82Se/76Se ratios, likely due to mixing processes in the proto-planetary nebula. When these isotopically heavier meteorites are excluded, remaining chondrites have δ82/76Se values varying over a 0.3‰ range, within uncertainty of previous results [2]. We suggest that these chondrites may be used to estimate a δ82/76Se value of bulk planets. At the conditions of our experiments, the partition coefficients for Se log Dmetal-silicate range from 0.7±0.1 to 1.9±0.1, consistent with previous work [1]. A small but resolvable Se isotopic fractionation was observed: 82Se/76Se ratios were enriched by ≤ 0.5‰ in the silicates relative to the metals. Thus, given current uncertainties for Se isotopic measurements, marginal differences between planetary mantles and chondrites may be resolved

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.

A simple test of one minute heart rate variability during deep breathing for evaluation of sympatovagal imbalance in hyperthyroidism.

PubMed

Shuvy, Mony; Arbelle, Jonathan E; Grosbard, Aviva; Katz, Amos

2008-01-01

Heart rate variability is a sensitive marker of cardiac sympathetic activity. To determine whether long-term hyperthyroidism induced by thyroxine suppressive therapy affects HRV. Nineteen patients treated with suppressive doses of thyroxin for thyroid cancer and 19 age-matched controls were enrolled. Thyroid function tests and 1 minute HRV were performed on all subjects and the results were compared between the groups. The 1 minute HRV was analyzed during deep breathing and defined as the difference in beats/minute between the shortest and the longest heart rate interval measured by eletrocardiographic recording during six cycles of deep breathing. One minute HRV during deep breathing was significantly lower among thyroxine-treated patients compared to healthy controls (25.6 +/- 10.5 vs. 34.3 +/- 12.6 beats/min, P < 0.05). There were no significant differences in mean, maximal and minimal heart rate between the groups. Thyroxine therapy administered for epithelial thyroid cancer resulted in subclinical hyperthyroidism and significantly decreased HRV due to autonomic dysfunction rather than basic elevated heart rate.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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.

An interlaboratory study to test instrument performance of hydrogen dual-inlet isotope-ratio mass spectrometers

USGS Publications Warehouse

Brand, Willi A.; Coplen, T.B.

2001-01-01

An interlaboratory comparison of forty isotope-ratio mass spectrometers of different ages from several vendors has been performed to test 2H/1H performance with hydrogen gases of three different isotopic compositions. The isotope-ratio results (unsufficiently corrected for H3+ contribution to the m/z = 3 collector, uncorrected for valve leakage in the change-over valves, etc.) expressed relative to one of these three gases covered a wide range of values: -630??? to -790??? for the second gas and -368??? to -462??? for the third gas. After normalizing the isotopic abundances of these test gases (linearly adjusting the ?? values so that the gases with the lowest and highest 2H content were identical for all laboratories), the standard deviation of the 40 measurements of the intermediate gas was a remarkably low 0.85???. It is concluded that the use of scaling factors is mandatory for providing accurate internationally comparable isotope-abundance values. Linear scaling for the isotope-ratio scales of gaseous hydrogen mass spectrometers is completely adequate. ?? Springer-Verlag 2001.

Breathing pattern and head posture: changes in craniocervical angles.

PubMed

Sabatucci, A; Raffaeli, F; Mastrovincenzo, M; Luchetta, A; Giannone, A; Ciavarella, D

2015-04-01

The aim of this study was to observe the influence of oral breathing on head posture and to establish possible postural changes observing the variation of craniocervical angles NSL/OPT and NSL/CVT between oral breathing subjects and physiological breathing subjects. A cross-sectional study was conducted. The sample included 115 subject, 56 boys and 59 girls, 5-22-year-old. Among these, 80 were classified as oral breathers and 35 as physiological breathers. The diagnosis of oral breathing was carried out thanks to characteristic signs and symptoms evaluated on clinical examination, the analysis of characteristic X-ray images, ENT examination with active anterior rhinomanometric (AAR) test. The structural and postural analysis was carried out, calculating the craniofacial angles NSL/OPT and NSL/CVT. Both NSL/OPT and NSL/CVT appear to be significantly greater to those observed in physiological breathing patients. This means that patients who tend to breathe through the mouth rather than exclusively through the nose show a reduction of cervical lordosis and a proinclination of the head. Our study confirms that the oral breathing modifies head position. The significant increase of the craniocervical angles NSL/OPT and NSL/CVT in patients with this altered breathing pattern suggests an elevation of the head and a greater extension of the head compared with the cervical spine. So, to correct the breathing pattern early, either during childhood or during adolescence, can lead to a progressive normalization of craniofacial morphology and head posture.

Guidelines proposal for clinical recognition of mouth breathing children.

PubMed

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

2015-01-01

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. The aim of this paper is to propose and test guidelines for clinical recognition of MB and some predisposing factors for SDB in children. 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. 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. 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.

Breathing and Relaxation

MedlinePlus

... Programs Health Information Doctors & Departments Clinical Research & Science Education & Training Home Health Insights Stress & Relaxation Breathing and Relaxation Breathing and Relaxation Make ...

Effect of alcohol consumption on the liver detoxication capacity as measured by [13C2]aminopyrine and L-[1-13C]phenylalanine breath tests.

PubMed

Wutzke, Klaus D; Wigger, Marianne

2009-09-01

The aim of this study was to investigate the hepatic microsomal and cytosolic functions by using the 13CO2 breath test in healthy subjects either before or after consumption of red wine. Twelve adults received [13C2]aminopyrine and L-[1-13C]phenylalanine together with a standardised dinner. Expired air samples were taken over 6 h. After a wash-out period, the subjects consumed 0.4 ml ethanol per kg per day together with dinner over a 7.5-day period on average. Thereafter, 13C-tracer administration was repeated under identical conditions. The 13CO2 enrichments were measured by isotope ratio mass spectrometry. The mean cumulative percentage 13C-dose recovery after administration of [13C2]aminopyrine and L-[1-13C]phenylalanine either without or with red wine consumption amounted to 17.0+/-4.4 vs. 14.7+/-3.1% (p=0.170) and 14.0+/-2.8 vs. 11.5+/-3.9% (p=0.084), respectively. Moderate alcohol consumption does not induce significant short-term changes of the microsomal and the cytosolic function of the human liver in healthy subjects.

Detection of bronchial breathing caused by pneumonia.

PubMed

Gross, V; Fachinger, P; Penzel, Th; Koehler, U; von Wichert, P; Vogelmeier, C

2002-06-01

The classic auscultation with stethoscope is the established clinical method for the detection of lung diseases. The interpretation of the sounds depends on the experience of the investigating physician. Therefore, a new computer-based method has been developed to classify breath sounds from digital lung sound recordings. Lung sounds of 11 patients with one-sided pneumonia and bronchial breathing were recorded on both the pneumonia side and on contralateral healthy side simultaneously using two microphones. The spectral power for the 300-600 Hz frequency band was computed for four respiratory cycles and normalized. For each breath, the ratio R between the time-segments (duration = 0.1 s) with the highest inspiratory and highest expiratory flow was calculated and averaged. We found significant differences in R between the pneumonia side (R = 1.4 +/- 1.3) and the healthy side (R = 0.5 +/- 0.5; p = 0.003 Wilcoxon-test) of lung. In 218 healthy volunteers we found R = 0.3 +/- 0.2 as a reference-value. The differences of ratio R (delta R) between the pneumonia side and the healthy side (delta R = 1.0 +/- 0.9) were significantly higher compared to follow-up studies after recovery (delta R = 0.0 +/- 0.1, p = 0.005 Wilcoxon-test). The computer based detection of bronchial breathing can be considered useful as part of a quantitative monitoring of patients at risk to develop pneumonia.

Deep breathing after surgery

MedlinePlus

... and taking big breaths can be uncomfortable. A device called an incentive spirometer can help you take deep breaths correctly. If you do not have this device, you can still practice deep breathing on your ...

Effect of influenza vaccination on oxidative stress products in breath.

PubMed

Phillips, Michael; Cataneo, Renee N; Chaturvedi, Anirudh; Danaher, Patrick J; Devadiga, Anantrai; Legendre, David A; Nail, Kim L; Schmitt, Peter; Wai, James

2010-06-01

Viral infections cause increased oxidative stress, so a breath test for oxidative stress biomarkers (alkanes and alkane derivatives) might provide a new tool for early diagnosis. We studied 33 normal healthy human subjects receiving scheduled treatment with live attenuated influenza vaccine (LAIV). Each subject was his or her own control, since they were studied on day 0 prior to vaccination, and then on days 2, 7 and 14 following vaccination. Breath volatile organic compounds (VOCs) were collected with a breath collection apparatus, then analyzed by automated thermal desorption with gas chromatography and mass spectroscopy. A Monte Carlo simulation technique identified non-random VOC biomarkers of infection based on their C-statistic values (area under curve of receiver operating characteristic). Treatment with LAIV was followed by non-random changes in the abundance of breath VOCs. 2, 8-Dimethyl-undecane and other alkane derivatives were observed on all days. Conservative multivariate models identified vaccinated subjects on day 2 (C-statistic = 0.82, sensitivity = 63.6% and specificity = 88.5%); day 7 (C-statistic = 0.94, sensitivity = 88.5% and specificity = 92.3%); and day 14 (C-statistic = 0.95, sensitivity = 92.3% and specificity = 92.3%). The altered breath VOCs were not detected in live attenuated influenza vaccine, excluding artifactual contamination. LAIV vaccination in healthy humans elicited a prompt and sustained increase in breath biomarkers of oxidative stress. A breath test for these VOCs could potentially identify humans who are acutely infected with influenza, but who have not yet developed clinical symptoms or signs of disease.

From breathing to respiration.

PubMed

Fitting, Jean-William

2015-01-01

The purpose of breathing remained an enigma for a long time. The Hippocratic school described breathing patterns but did not associate breathing with the lungs. Empedocles and Plato postulated that breathing was linked to the passage of air through pores of the skin. This was refuted by Aristotle who believed that the role of breathing was to cool the heart. In Alexandria, breakthroughs were accomplished in the anatomy and physiology of the respiratory system. Later, Galen proposed an accurate description of the respiratory muscles and the mechanics of breathing. However, his heart-lung model was hampered by the traditional view of two non-communicating vascular systems - veins and arteries. After a period of stagnation in the Middle Ages, knowledge progressed with the discovery of pulmonary circulation. The comprehension of the purpose of breathing progressed by steps thanks to Boyle and Mayow among others, and culminated with the contribution of Priestley and the discovery of oxygen by Lavoisier. Only then was breathing recognized as fulfilling the purpose of respiration, or gas exchange. A century later, a controversy emerged concerning the active or passive transfer of oxygen from alveoli to the blood. August and Marie Krogh settled the dispute, showing that passive diffusion was sufficient to meet the oxygen needs. © 2014 S. Karger AG, Basel.

Spike-Timing of Orbitofrontal Neurons Is Synchronized With Breathing.

PubMed

Kőszeghy, Áron; Lasztóczi, Bálint; Forro, Thomas; Klausberger, Thomas

2018-01-01

The orbitofrontal cortex (OFC) has been implicated in a multiplicity of complex brain functions, including representations of expected outcome properties, post-decision confidence, momentary food-reward values, complex flavors and odors. As breathing rhythm has an influence on odor processing at primary olfactory areas, we tested the hypothesis that it may also influence neuronal activity in the OFC, a prefrontal area involved also in higher order processing of odors. We recorded spike timing of orbitofrontal neurons as well as local field potentials (LFPs) in awake, head-fixed mice, together with the breathing rhythm. We observed that a large majority of orbitofrontal neurons showed robust phase-coupling to breathing during immobility and running. The phase coupling of action potentials to breathing was significantly stronger in orbitofrontal neurons compared to cells in the medial prefrontal cortex. The characteristic synchronization of orbitofrontal neurons with breathing might provide a temporal framework for multi-variable processing of olfactory, gustatory and reward-value relationships.

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

PubMed

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

2013-01-01

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

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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. pylorimore » 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.« less

Diagnosis of acute respiratory distress syndrome by exhaled breath analysis

PubMed Central

2018-01-01

The acute respiratory distress syndrome (ARDS) is a complication of critical illness that is characterized by acute onset, protein rich, pulmonary edema. There is no treatment for ARDS, other than the reduction of additional ventilator induced lung injury. Prediction or earlier recognition of ARDS could result in preventive measurements and might decrease mortality and morbidity. Exhaled breath contains volatile organic compounds (VOCs), a collection of hundreds of small molecules linked to several physiological and pathophysiological processes. Analysis of exhaled breath through gas-chromatography and mass-spectrometry (GC-MS) has resulted in an accurate diagnosis of ARDS in several studies. Most identified markers are linked to lipid peroxidation. Octane is one of the few markers that was validated as a marker of ARDS and is pathophysiologically likely to be increased in ARDS. None of the currently studied breath analysis methods is directly applicable in clinical practice. Two steps have to be taken before any breath test can be allowed into the intensive care unit. External validation in a multi-center study is a prerequisite for any of the candidate breath markers and the breath test should outperform clinical prediction scores. Second, the technology for breath analysis should be adapted so that it is available at a decentralized lab inside the intensive care unit and can be operated by trained nurses, in order to reduce the analysis time. In conclusion, exhaled analysis might be used for the early diagnosis and prediction of ARDS in the near future but several obstacles have to be taken in the coming years. Most of the candidate markers can be linked to lipid peroxidation. Only octane has been validated in a temporal external validation cohort and is, at this moment, the top-ranking breath biomarker for ARDS. PMID:29430450

Measurement of starch digestion of naturally 13C-enriched weaning foods, before and after partial digestion with amylase-rich flour, using a 13C breath test.

PubMed

Weaver, L T; Dibba, B; Sonko, B; Bohane, T D; Hoare, S

1995-10-01

Malnutrition in infancy is a global problem which leads to retardation of childhood growth and development. There is a pressing need to improve weaning strategies for infants of the developing world. Traditional Gambian weaning foods are watery and of low energy density, but addition of energy in the form of fat and carbohydrate leads to thick, viscous gruels which are difficult to ingest. Partial digestion with amylase (EC 3.2.1.1)-rich flour reduces their viscosity while retaining their energy density. The aim of the present study was to measure the digestibility of a maize-based weaning food, before and after amylase digestion, in malnourished children using a 13C breath test. Ten children (aged 7-16 months; mean weight-for-age Z score -0.8) received isovolumetric and isoenergetic quantities of a maize-based weaning food naturally abundant with 13C. Breath samples were collected at intervals of 30 min for 5 h thereafter and 13CO2 enrichment was measured by isotope-ratio mass spectrometry. Percentage dose of 13C recovered increased from a mean 13.7 (SD 3.7)% before, to 18.3 (SD 5.6)% after ingestion of amylase-treated weaning foods (P < 0.1). There was a significant inverse relation between age and weight, and percentage dose of 13C recovered in children receiving amylase-treated feeds. There were no differences in concentrations of amylase in saliva of infants or breast milk of their mothers. Partial digestion of supplementary foods may improve the nutrition of undernourished weaning children, not only by reducing their viscosity, thereby increasing ingestion, but also by improving their digestion and thereby their absorption.

[Effects of breathing exercises on breathing pattern and thoracoabdominal motion after gastroplasty].

PubMed

Tomich, Georgia Miranda; França, Danielle Corrêa; Diniz, Marco Túlio Costa; Britto, Raquel Rodrigues; Sampaio, Rosana Ferreira; Parreira, Verônica Franco

2010-01-01

To evaluate breathing pattern and thoracoabdominal motion during breathing exercises. Twenty-four patients with class II or III obesity (18 women; 6 men) were studied on the second postoperative day after gastroplasty. The mean age was 37 +/- 11 years, and the mean BMI was 44 +/- 3 kg/m(2). Diaphragmatic breathing, incentive spirometry with a flow-oriented device and incentive spirometry with a volume-oriented device were performed in random order. Respiratory inductive plethysmography was used in order to measure respiratory variables and thoracoabdominal motion. Comparisons among the three exercises showed significant differences: tidal volume was higher during incentive spirometry (with the flow-oriented device or with the volume-oriented device) than during diaphragmatic breathing; the respiratory rate was lower during incentive spirometry with the volume-oriented device than during incentive spirometry with the flow-oriented device; and minute ventilation was higher during incentive spirometry (with the flow-oriented device or with the volume-oriented device) than during diaphragmatic breathing. Rib cage motion did not vary during breathing exercises, although there was an increase in thoracoabdominal asynchrony, especially during incentive spirometry with the flow-oriented device. Among the breathing exercises evaluated, incentive spirometry with the volume-oriented device provided the best results, because it allowed slower, deeper inhalation.

A simple, remote, video based breathing monitor.

PubMed

Regev, Nir; Wulich, Dov

2017-07-01

Breathing monitors have become the all-important cornerstone of a wide variety of commercial and personal safety applications, ranging from elderly care to baby monitoring. Many such monitors exist in the market, some, with vital signs monitoring capabilities, but none remote. This paper presents a simple, yet efficient, real time method of extracting the subject's breathing sinus rhythm. Points of interest are detected on the subject's body, and the corresponding optical flow is estimated and tracked using the well known Lucas-Kanade algorithm on a frame by frame basis. A generalized likelihood ratio test is then utilized on each of the many interest points to detect which is moving in harmonic fashion. Finally, a spectral estimation algorithm based on Pisarenko harmonic decomposition tracks the harmonic frequency in real time, and a fusion maximum likelihood algorithm optimally estimates the breathing rate using all points considered. The results show a maximal error of 1 BPM between the true breathing rate and the algorithm's calculated rate, based on experiments on two babies and three adults.

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...

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

PubMed Central

Cheepsattayakorn, Attapon; Cheepsattayakorn, Ruangrong

2013-01-01

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

Guiding curve based on the normal breathing as monitored by thermocouple for regular breathing.

PubMed

Lim, Sangwook; Park, Sung Ho; Ahn, Seung Do; Suh, Yelin; Shin, Seong Soo; Lee, Sang-wook; Kim, Jong Hoon; Choi, Eun Kyoung; Yi, Byong Yong; Kwon, Soo Il; Kim, Sookil; Jeung, Tae Sig

2007-11-01

Adapting radiation fields to a moving target requires information continuously on the location of internal target by detecting it directly or indirectly. The aim of this study is to make the breathing regular effectively with minimizing stress to the patient. A system for regulating patient's breath consists of a respiratory monitoring mask (ReMM), a thermocouple module, a screen, inner earphones, and a personal computer. A ReMM with thermocouple was developed previously to measure the patient's respiration. A software was written in LabView 7.0 (National Instruments, TX), which acquires respiration signal and displays its pattern. Two curves are displayed on the screen: One is a curve indicating the patient's current breathing pattern; the other is a guiding curve, which is iterated with one period of the patient's normal breathing curve. The guiding curves were acquired for each volunteer before they breathed with guidance. Ten volunteers participated in this study to evaluate this system. A cycle of the representative guiding curve was acquired by monitoring each volunteer's free breathing with ReMM and was then generated iteratively. The regularity was compared between a free breath curve and a guided breath curve by measuring standard deviations of amplitudes and periods of two groups of breathing. When the breathing was guided, the standard deviation of amplitudes and periods on average were reduced from 0.0029 to 0.00139 (arbitrary units) and from 0.359 s to 0.202 s, respectively. And the correlation coefficients between breathing curves and guiding curves were greater than 0.99 for all volunteers. The regularity was improved statistically when the guiding curve was used.

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

Code of Federal Regulations, 2010 CFR

2010-10-01

... 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 adapter...

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

Code of Federal Regulations, 2014 CFR

2014-10-01

... 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 adapter...

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

Code of Federal Regulations, 2011 CFR

2011-10-01

... 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 adapter...

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

Code of Federal Regulations, 2013 CFR

2013-10-01

... 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 adapter...

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

Code of Federal Regulations, 2012 CFR

2012-10-01

... 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 adapter...

A test of geographic assignment using isotope tracers in feathers of known origin

USGS Publications Warehouse

Wunder, Michael B.; Kester, C.L.; Knopf, F.L.; Rye, R.O.

2005-01-01

We used feathers of known origin collected from across the breeding range of a migratory shorebird to test the use of isotope tracers for assigning breeding origins. We analyzed δD, δ13C, and δ15N in feathers from 75 mountain plover (Charadrius montanus) chicks sampled in 2001 and from 119 chicks sampled in 2002. We estimated parameters for continuous-response inverse regression models and for discrete-response Bayesian probability models from data for each year independently. We evaluated model predictions with both the training data and by using the alternate year as an independent test dataset. Our results provide weak support for modeling latitude and isotope values as monotonic functions of one another, especially when data are pooled over known sources of variation such as sample year or location. We were unable to make even qualitative statements, such as north versus south, about the likely origin of birds using both δD and δ13C in inverse regression models; results were no better than random assignment. Probability models provided better results and a more natural framework for the problem. Correct assignment rates were highest when considering all three isotopes in the probability framework, but the use of even a single isotope was better than random assignment. The method appears relatively robust to temporal effects and is most sensitive to the isotope discrimination gradients over which samples are taken. We offer that the problem of using isotope tracers to infer geographic origin is best framed as one of assignment, rather than prediction.

Noise Reduction in Breath Sound Files Using Wavelet Transform Based Filter

NASA Astrophysics Data System (ADS)

Syahputra, M. F.; Situmeang, S. I. G.; Rahmat, R. F.; Budiarto, R.

2017-04-01

The development of science and technology in the field of healthcare increasingly provides convenience in diagnosing respiratory system problem. Recording the breath sounds is one example of these developments. Breath sounds are recorded using a digital stethoscope, and then stored in a file with sound format. This breath sounds will be analyzed by health practitioners to diagnose the symptoms of disease or illness. However, the breath sounds is not free from interference signals. Therefore, noise filter or signal interference reduction system is required so that breath sounds component which contains information signal can be clarified. In this study, we designed a filter called a wavelet transform based filter. The filter that is designed in this study is using Daubechies wavelet with four wavelet transform coefficients. Based on the testing of the ten types of breath sounds data, the data is obtained in the largest SNRdB bronchial for 74.3685 decibels.

Effects of breathing exercises on breathing patterns in obese and non-obese subjects.

PubMed

Olsén, M F; Lönroth, H; Bake, B

1999-05-01

Chest physiotherapy in connection with abdominal surgery includes different deep-breathing exercises to prevent post-operative pulmonary complications. The therapy is effective in preventing pulmonary complications, especially in high-risk patients such as obese persons. The mechanisms behind the effect is unclear, but part of the effect may be explained by the changes in breathing patterns. The aim of this study was therefore to describe and to analyse the breathing patterns in obese and non-obese subjects during three different breathing techniques frequently used in the treatment of post-operative patients. Twenty-one severely obese [body mass index (BMI) > 40] and 21 non-obese (BMI 19-25) subjects were studied. All persons denied having any lung disease and were non-smokers. The breathing techniques investigated were: deep breaths without any resistance (DB), positive expiratory pressure (PEP) with an airway resistance of approximately +15 cmH2O (1.5 kPa) during expiration, inspiratory resistance positive expiratory pressure (IR-PEP) with a pressure of approximately -10 cmH2O (-1.0 kPa) during inspiration. Expiratory resistance as for PEP. Volume against time was monitored while the subjects were sitting in a body plethysmograph. Variables for volume and flow during the breathing cycle were determined. Tidal volume and alveolar ventilation were highest during DB, and peak inspiratory volume was significantly higher than during PEP and IR-PEP in the group of obese subjects. The breathing cycles were prolonged in all techniques but were most prolonged in PEP and IR-PEP. The functional residual capacity (FRC) was significantly lower during DB than during PEP and IR-PEP in the group of obese subjects. FRC as determined within 2 min of finishing each breathing technique was identical to before the breathing manoeuvres.

A fully integrated standalone portable cavity ringdown breath acetone analyzer.

PubMed

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.

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.

Individuality of breathing during volitional moderate hyperventilation.

PubMed

Besleaga, Tudor; Blum, Michaël; Briot, Raphaël; Vovc, Victor; Moldovanu, Ion; Calabrese, Pascale

2016-01-01

The aim of this study is to investigate the individuality of airflow shapes during volitional hyperventilation. Ventilation was recorded on 18 healthy subjects following two protocols: (1) spontaneous breathing (SP1) followed by a volitional hyperventilation at each subject's spontaneous (HVSP) breathing rate, (2) spontaneous breathing (SP2) followed by hyperventilation at 20/min (HV20). HVSP and HV20 were performed at the same level of hypocapnia: end tidal CO2 (FETCO2) was maintained at 1% below the spontaneous level. At each breath, the tidal volume (VT), the breath (TTOT), the inspiratory (TI) and expiratory durations, the minute ventilation, VT/TI, TI/TTOT and the airflow shape were quantified by harmonic analysis. Under different conditions of breathing, we test if the airflow profiles of the same individual are more similar than airflow profiles between individuals. Minute ventilation was not significantly different between SP1 (6.71 ± 1.64 l·min(-1)) and SP2 (6.57 ± 1.31 l·min(-1)) nor between HVSP (15.88 ± 4.92 l·min(-1)) and HV20 (15.87 ± 4.16 l·min(-1)). Similar results were obtained for FETCO2 between SP1 (5.06 ± 0.54 %) and SP2 (5.00 ± 0.51%), and HVSP (4.07 ± 0.51%) and HV20 (3.88 ± 0.42%). Only TI/TTOT remained unchanged in all four conditions. Airflow shapes were similar when comparing SP1-SP2, HVSP-HV20, and SP1-HVSP but not similar when comparing SP2-HV20. These results suggest the existence of an individuality of airflow shape during volitional hyperventilation. We conclude that volitional ventilation alike automatic breathing follows inherent properties of the ventilatory system. Registered by Pascale Calabrese on ClinicalTrials.gov, # NCT01881945.

Rapid shallow breathing

MedlinePlus

Tachypnea; Breathing - rapid and shallow; Fast shallow breathing; Respiratory rate - rapid and shallow ... Kraft M. Approach to the patient with respiratory disease. In: ... Elsevier Saunders; 2016:chap 83. McGee S. Respiratory rate and ...

Breath in the technoscientific imaginary

PubMed Central

Rose, Arthur

2016-01-01

Breath has a realist function in most artistic media. It serves to remind the reader, the viewer or the spectator of the exigencies of the body. In science fiction (SF) literature and films, breath is often a plot device for human encounters with otherness, either with alien peoples, who may not breathe oxygen, or environments, where there may not be oxygen to breathe. But while there is a technoscientific quality to breath in SF, especially in its attention to physiological systems, concentrating on the technoscientific threatens to occlude other, more affective aspects raised by the literature. In order to supplement the tendency to read SF as a succession of technoscientific accounts of bodily experience, this paper recalls how SF texts draw attention to the affective, non-scientific qualities of breath, both as a metonym for life and as a metaphor for anticipation. Through an engagement with diverse examples from SF literature and films, this article considers the tension between technoscientific and affective responses to breath in order to demonstrate breath's co-determinacy in SF's blending of scientific and artistic discourses. PMID:27542677

The Effect of Diaphragmatic Breathing on Attention, Negative Affect and Stress in Healthy Adults.

PubMed

Ma, Xiao; Yue, Zi-Qi; Gong, Zhu-Qing; Zhang, Hong; Duan, Nai-Yue; Shi, Yu-Tong; Wei, Gao-Xia; Li, You-Fa

2017-01-01

A growing number of empirical studies have revealed that diaphragmatic breathing may trigger body relaxation responses and benefit both physical and mental health. However, the specific benefits of diaphragmatic breathing on mental health remain largely unknown. The present study aimed to investigate the effect of diaphragmatic breathing on cognition, affect, and cortisol responses to stress. Forty participants were randomly assigned to either a breathing intervention group (BIG) or a control group (CG). The BIG received intensive training for 20 sessions, implemented over 8 weeks, employing a real-time feedback device, and an average respiratory rate of 4 breaths/min, while the CG did not receive this treatment. All participants completed pre- and post-tests of sustained attention and affect. Additionally, pre-test and post-test salivary cortisol concentrations were determined in both groups. The findings suggested that the BIG showed a significant decrease in negative affect after intervention, compared to baseline. In the diaphragmatic breathing condition, there was a significant interaction effect of group by time on sustained attention, whereby the BIG showed significantly increased sustained attention after training, compared to baseline. There was a significant interaction effect of group and time in the diaphragmatic breathing condition on cortisol levels, whereby the BIG had a significantly lower cortisol level after training, while the CG showed no significant change in cortisol levels. In conclusion, diaphragmatic breathing could improve sustained attention, affect, and cortisol levels. This study provided evidence demonstrating the effect of diaphragmatic breathing, a mind-body practice, on mental function, from a health psychology approach, which has important implications for health promotion in healthy individuals.

Breathing efficiency during inspiratory threshold loading in patients with chronic obstructive pulmonary disease.

PubMed

Baarends, E M; Schols, A M; Nusmeier, C M; van der Grinten, C P; Wouters, E F

1998-05-01

Patients with chronic obstructive pulmonary disease (COPD) demonstrate an increased oxygen cost of breathing. It is as yet unclear whether this is related to a decreased breathing efficiency. The aim of the present study was to compare breathing efficiency in 16 patients with COPD (11 men, five women) and 16 healthy elderly subjects (seven men, nine women), and to investigate a possible relationship between breathing efficiency and resting energy expenditure (REE). REE was measured using a ventilated hood system. Breathing efficiency was assessed by measuring oxygen consumption (V'O2), mean inspiratory mouth pressure (MIP) and flow during breathing at rest and subsequently during breathing against an inspiratory threshold (40% of maximal inspiratory pressure). During loaded breathing there was a significant increase in V'O2, MIP, and external work of breathing compared with unloaded breathing in both groups. As intended, ventilation did not increase significantly during the breathing efficiency test in the patients with COPD. The breathing efficiency (median, range) of the patients with COPD was similar (3.7%, 1.4-8.7%) to that of the healthy elderly subjects (3.2%, 1.7-8.3%). Breathing efficiency was not correlated with REE in either group. In the present study, in which dynamic hyperinflation was probably prevented, no difference in breathing efficiency was found between healthy elderly subjects and COPD patients when breathing against an external inspiratory threshold. Furthermore, breathing efficiency was not related to REE in both groups.

Recovery of Percent Vital Capacity by Breathing Training in Patients With Panic Disorder and Impaired Diaphragmatic Breathing.

PubMed

Yamada, Tatsuji; Inoue, Akiomi; Mafune, Kosuke; Hiro, Hisanori; Nagata, Shoji

2017-09-01

Slow diaphragmatic breathing is one of the therapeutic methods used in behavioral therapy for panic disorder. In practice, we have noticed that some of these patients could not perform diaphragmatic breathing and their percent vital capacity was initially reduced but could be recovered through breathing training. We conducted a comparative study with healthy controls to investigate the relationship between diaphragmatic breathing ability and percent vital capacity in patients with panic disorder. Our findings suggest that percent vital capacity in patients with impaired diaphragmatic breathing was significantly reduced compared with those with normal diaphragmatic breathing and that diaphragmatic breathing could be restored by breathing training. Percent vital capacity of the healthy controls was equivalent to that of the patients who had completed breathing training. This article provides preliminary findings regarding reduced vital capacity in relation to abnormal respiratory movements found in patients with panic disorder, potentially offering alternative perspectives for verifying the significance of breathing training for panic disorder.

DEVELOPMENT OF A SCREENING PROTOCOL TO IDENTIFY INDIVIDUALS WITH DYSFUNCTIONAL BREATHING

PubMed Central

Kiesel, Kyle; Rhodes, Tonya; Mueller, Jacob; Waninger, Alyssa; Butler, Robert

2017-01-01

Introduction Dysfunctional breathing (DB) has been linked to health conditions including low back pain and neck pain and adversely effects the musculoskeletal system. Individuals with DB often have decreased pain thresholds and impaired motor control, balance, and movement. No single test or screen identifies DB, which is multi-dimensional, and includes biochemical, biomechanical, and psychophysiological components. Several tools assess and test for DB, but no screen exists to determine whether additional testing and assessment are indicated. Purpose/Background The purpose of this study was to develop a breathing screening procedure that could be utilized by fitness and healthcare providers to screen for the presence of disordered breathing. A diagnostic test study approach was utilized to establish the diagnostic accuracy of the newly developed screen for DB. Methods A convenience sample of 51 subjects (27 females, 27.0 years, BMI 23.3) were included. To test for DB related to the biochemical dimension, end-tidal CO2 (ETCO2) was measured with a capnography unit. To test for DB related to biomechanical dimension, the Hi-Lo test was utilized. To test for DB related to the psychophysiological dimension, the Self Evaluation of Breathing Symptoms Questionnaire (SEBQ) and Nijmegen questionnaires were utilized. Potential screening items that have been shown to be related to DB in previous research and that could be performed by non-health care personnel were utilized to create the index test including activity level, breath hold time (BHT), respiration rate, and the Functional Movement Screen (FMS™). Results There were no strong correlations between the three measures of DB. Five subjects had normal breathing, 14 failed at least one measure, 20 failed at least two, and 12 failed all three. To develop screening items for each dimension, data were examined for association with failure. BHT and a four-item mini-questionnaire were identified as the most closely associated

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

Quantification of the thorax-to-abdomen breathing ratio for breathing motion modeling.

PubMed

White, Benjamin M; Zhao, Tianyu; Lamb, James; Bradley, Jeffrey D; Low, Daniel A

2013-06-01

The purpose of this study was to develop a methodology to quantitatively measure the thorax-to-abdomen breathing ratio from a 4DCT dataset for breathing motion modeling and breathing motion studies. The thorax-to-abdomen breathing ratio was quantified by measuring the rate of cross-sectional volume increase throughout the thorax and abdomen as a function of tidal volume. Twenty-six 16-slice 4DCT patient datasets were acquired during quiet respiration using a protocol that acquired 25 ciné scans at each couch position. Fifteen datasets included data from the neck through the pelvis. Tidal volume, measured using a spirometer and abdominal pneumatic bellows, was used as breathing-cycle surrogates. The cross-sectional volume encompassed by the skin contour when compared for each CT slice against the tidal volume exhibited a nearly linear relationship. A robust iteratively reweighted least squares regression analysis was used to determine η(i), defined as the amount of cross-sectional volume expansion at each slice i per unit tidal volume. The sum Ση(i) throughout all slices was predicted to be the ratio of the geometric expansion of the lung and the tidal volume; 1.11. The Xiphoid process was selected as the boundary between the thorax and abdomen. The Xiphoid process slice was identified in a scan acquired at mid-inhalation. The imaging protocol had not originally been designed for purposes of measuring the thorax-to-abdomen breathing ratio so the scans did not extend to the anatomy with η(i) = 0. Extrapolation of η(i)-η(i) = 0 was used to include the entire breathing volume. The thorax and abdomen regions were individually analyzed to determine the thorax-to-abdomen breathing ratios. There were 11 image datasets that had been scanned only through the thorax. For these cases, the abdomen breathing component was equal to 1.11 - Ση(i) where the sum was taken throughout the thorax. The average Ση(i) for thorax and abdomen image datasets was found to be 1.20 �

Tenth anniversary special issue of the Journal of Breath Research: looking forward

EPA Science Inventory

The Journal of Breath Research has now reached its 10th anniversary of publication. From the general public’s perspective, breath analysis had always revolved around drinking and driving, and to some lesser extent pulmonary function testing of athletes. However, at the ince...

Modeling the isotopic evolution of snowpack and snowmelt: Testing a spatially distributed parsimonious approach.

PubMed

Ala-Aho, Pertti; Tetzlaff, Doerthe; McNamara, James P; Laudon, Hjalmar; Kormos, Patrick; Soulsby, Chris

2017-07-01

Use of stable water isotopes has become increasingly popular in quantifying water flow paths and travel times in hydrological systems using tracer-aided modeling. In snow-influenced catchments, snowmelt produces a traceable isotopic signal, which differs from original snowfall isotopic composition because of isotopic fractionation in the snowpack. These fractionation processes in snow are relatively well understood, but representing their spatiotemporal variability in tracer-aided studies remains a challenge. We present a novel, parsimonious modeling method to account for the snowpack isotope fractionation and estimate isotope ratios in snowmelt water in a fully spatially distributed manner. Our model introduces two calibration parameters that alone account for the isotopic fractionation caused by sublimation from interception and ground snow storage, and snowmelt fractionation progressively enriching the snowmelt runoff. The isotope routines are linked to a generic process-based snow interception-accumulation-melt model facilitating simulation of spatially distributed snowmelt runoff. We use a synthetic modeling experiment to demonstrate the functionality of the model algorithms in different landscape locations and under different canopy characteristics. We also provide a proof-of-concept model test and successfully reproduce isotopic ratios in snowmelt runoff sampled with snowmelt lysimeters in two long-term experimental catchment with contrasting winter conditions. To our knowledge, the method is the first such tool to allow estimation of the spatially distributed nature of isotopic fractionation in snowpacks and the resulting isotope ratios in snowmelt runoff. The method can thus provide a useful tool for tracer-aided modeling to better understand the integrated nature of flow, mixing, and transport processes in snow-influenced catchments.

Detection of nitric oxide in exhaled human breath: exercise and resting determinations.

PubMed

Mantione, Kirk J; Esch, Tobias; Stefano, George B

2007-03-01

Nitric oxide has become a vital indicator of health since many cells produce it constitutively. It is present in exhaled breath and can be measured. A Kiernan NO Breath analyzer (KNB) was used in the present study to determine nitric oxide (NO) levels in exhaled human breath. The KNB was calibrated via measuring NO gas in O2-free N2 obtained from Scott Specialty Gases. Human subjects aged 21 to 45 were instructed to place the KNB over their nose and mouth and to breathe normally before and after mild exercise (n=24) and relaxation (n=20). Mean exhaled NO measurements were compared before and after the protocols using paired t-tests. Regardless of the test, all subjects exhibited NO in their exhaled breath. Exhaled NO decreased significantly after exercise compared to the first reading just prior to the exercise protocol. The mean +/-SE of exhaled NO was 22.8+/-4 before and 13.0+/-2 ppb after exercise (n=24, P=0.003). In the resting experiment, exhaled NO was demonstrated to increase significantly after 10 min compared to the reading taken right after the individuals sat down. The present study demonstrates NO in exhaled human breath can vary, reflecting the activity state of the individual. Additionally, the study demonstrates that NO in exhaled human breath can be measured rapidly, with high sensitivity, and in real time via the KNB, representing an affordable means to achieve this determination.

Whole-heart magnetic resonance coronary angiography with multiple breath-holds and automatic breathing-level tracking

NASA Astrophysics Data System (ADS)

Kuhara, Shigehide; Ninomiya, Ayako; Okada, Tomohisa; Kanao, Shotaro; Kamae, Toshikazu; Togashi, Kaori

2010-05-01

Whole-heart (WH) magnetic resonance coronary angiography (MRCA) studies are usually performed during free breathing while monitoring the position of the diaphragm with real-time motion correction. However, this results in a long scan time and the patient's breathing pattern may change, causing the study to be aborted. Alternatively, WH MRCA can be performed with multiple breath-holds (mBH). However, one problem in the mBH method is that patients cannot hold their breath at the same position every time, leading to image degradation. We have developed a new WH MRCA imaging method that employs both the mBH method and automatic breathing-level tracking to permit automatic tracking of the changes in breathing or breath-hold levels. Evaluation of its effects on WH MRCA image quality showed that this method can provide high-quality images within a shorter scan time. This proposed method is expected to be very useful in clinical WH MRCA studies.

How to deal with morning bad breath: A randomized, crossover clinical trial.

PubMed

Oliveira-Neto, Jeronimo M; Sato, Sandra; Pedrazzi, Vinícius

2013-11-01

The absence of a protocol for the treatment of halitosis has led us to compare mouthrinses with mechanical oral hygiene procedures for treating morning breath by employing a hand-held sulfide monitor. To compare the efficacy of five modalities of treatment for controlling morning halitosis in subjects with no dental or periodontal disease. This is a five-period, randomized, crossover clinical trial. Twenty volunteers were randomly assigned to the trial. Testing involved the use of a conventional tongue scraper, a tongue scraper joined to the back of a toothbrush's head, two mouthrinses (0.05% cetylpyridinium chloride and 0.12% chlorhexidine digluconate) and a soft-bristled toothbrush and fluoride toothpaste for practicing oral hygiene. Data analysis was performed using SPSS version 17 for Windows and NCSS 2007 software (P < 0.05). The products and the periods were compared with each other using the Friedman's test. When significant differences (P < 0.05) were determined, the products and periods were compared in pairs by using the Wilcoxon's test and by adjusting the original significance level (0.05) for multiple comparisons by using the Bonferroni's method. The toothbrush's tongue scraper was able to significantly reduce bad breath for up to 2 h. Chlorhexidine reduced bad breath only at the end of the second hour, an effect that lasted for 3 h. Mechanical tongue cleaning was able to immediately reduce bad breath for a short period, whereas chlorhexidine and mechanical oral hygiene reduced bad breath for longer periods, achieving the best results against morning breath.

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

PubMed Central

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, T

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

2016-07-30

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

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...

Breath in the technoscientific imaginary.

PubMed

Rose, Arthur

2016-12-01

Breath has a realist function in most artistic media. It serves to remind the reader, the viewer or the spectator of the exigencies of the body. In science fiction (SF) literature and films, breath is often a plot device for human encounters with otherness, either with alien peoples, who may not breathe oxygen, or environments, where there may not be oxygen to breathe. But while there is a technoscientific quality to breath in SF, especially in its attention to physiological systems, concentrating on the technoscientific threatens to occlude other, more affective aspects raised by the literature. In order to supplement the tendency to read SF as a succession of technoscientific accounts of bodily experience, this paper recalls how SF texts draw attention to the affective, non-scientific qualities of breath, both as a metonym for life and as a metaphor for anticipation. Through an engagement with diverse examples from SF literature and films, this article considers the tension between technoscientific and affective responses to breath in order to demonstrate breath's co-determinacy in SF's blending of scientific and artistic discourses. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

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. Copyright © 2014 Elsevier B.V. All rights reserved.

Practice It: Deep Conscious Breathing Exercise

Cancer.gov

No time to sit and breathe? No problem; take your breathing practice with you! Deep conscious breathing can also be done with the eyes open wherever you happen to be—simply pause and take two to three full deep breaths (inhale deeply and exhale completely).

Dosimetric comparison of moderate deep inspiration breath-hold and free-breathing intensity-modulated radiotherapy for left-sided breast cancer.

PubMed

Chi, F; Wu, S; Zhou, J; Li, F; Sun, J; Lin, Q; Lin, H; Guan, X; He, Z

2015-05-01

This study determined the dosimetric comparison of moderate deep inspiration breath-hold using active breathing control and free-breathing intensity-modulated radiotherapy (IMRT) after breast-conserving surgery for left-sided breast cancer. Thirty-one patients were enrolled. One free breathe and two moderate deep inspiration breath-hold images were obtained. A field-in-field-IMRT free-breathing plan and two field-in-field-IMRT moderate deep inspiration breath-holding plans were compared in the dosimetry to target volume coverage of the glandular breast tissue and organs at risks for each patient. The breath-holding time under moderate deep inspiration extended significantly after breathing training (P<0.05). There was no significant difference between the free-breathing and moderate deep inspiration breath-holding in the target volume coverage. The volume of the ipsilateral lung in the free-breathing technique were significantly smaller than the moderate deep inspiration breath-holding techniques (P<0.05); however, there was no significant difference between the two moderate deep inspiration breath-holding plans. There were no significant differences in target volume coverage between the three plans for the field-in-field-IMRT (all P>0.05). The dose to ipsilateral lung, coronary artery and heart in the field-in-field-IMRT were significantly lower for the free-breathing plan than for the two moderate deep inspiration breath-holding plans (all P<0.05); however, there was no significant difference between the two moderate deep inspiration breath-holding plans. The whole-breast field-in-field-IMRT under moderate deep inspiration breath-hold with active breathing control after breast-conserving surgery in left-sided breast cancer can reduce the irradiation volume and dose to organs at risks. There are no significant differences between various moderate deep inspiration breath-holding states in the dosimetry of irradiation to the field-in-field-IMRT target volume

Effect of oxygenation on breath-by-breath response of the genioglossus muscle during occlusion.

PubMed

Gauda, E B; Carroll, J L; McColley, S; Smith, P L

1991-10-01

We investigated the effect of different levels of O2 tension (hypoxia, normoxia, and hyperoxia) on the breath-by-breath onset and peak electromyographic (EMG) activity of the genioglossus (GG) muscle during a five-breath end-expiratory tracheal occlusion of 20- to 30-s duration. GG and diaphragmatic (DIA) EMG activity were measured with needle electrodes in eight anesthetized tracheotomized adult cats. In response to occlusion, the increase in the number of animals with GG EMG activity was different during hypoxia, normoxia, and hyperoxia (P = 0.003, Friedman). During hypoxia, eight of eight of the animals had GG EMG activity by the third occluded effort. In contrast, during normoxia, only four of eight and, during hyperoxia, only three of eight animals had GG EMG activity throughout the entire five-breath occlusion. Similarly, at release of the occlusion, more animals had persistent GG EMG activity on the postocclusion breaths during hypoxia than during normoxia or hyperoxia. Breath-by-breath augmentation of peak amplitude of the GG and DIA EMGs on each occluded effort was accentuated during hypoxia (P less than 0.01) and abolished during hyperoxia (P = 0.10). These results suggest that hypoxemia is a major determinant of the rapidity of onset, magnitude, and sustained activity of upper airway muscles during airway occlusion.

Isotope engineering of van der Waals interactions in hexagonal boron nitride

NASA Astrophysics Data System (ADS)

Vuong, T. Q. P.; Liu, S.; van der Lee, A.; Cuscó, R.; Artús, L.; Michel, T.; Valvin, P.; Edgar, J. H.; Cassabois, G.; Gil, B.

2018-02-01

Hexagonal boron nitride is a model lamellar compound where weak, non-local van der Waals interactions ensure the vertical stacking of two-dimensional honeycomb lattices made of strongly bound boron and nitrogen atoms. We study the isotope engineering of lamellar compounds by synthesizing hexagonal boron nitride crystals with nearly pure boron isotopes (10B and 11B) compared to those with the natural distribution of boron (20 at% 10B and 80 at% 11B). On the one hand, as with standard semiconductors, both the phonon energy and electronic bandgap varied with the boron isotope mass, the latter due to the quantum effect of zero-point renormalization. On the other hand, temperature-dependent experiments focusing on the shear and breathing motions of adjacent layers revealed the specificity of isotope engineering in a layered material, with a modification of the van der Waals interactions upon isotope purification. The electron density distribution is more diffuse between adjacent layers in 10BN than in 11BN crystals. Our results open perspectives in understanding and controlling van der Waals bonding in layered materials.

Isotope engineering of van der Waals interactions in hexagonal boron nitride.

PubMed

Vuong, T Q P; Liu, S; Van der Lee, A; Cuscó, R; Artús, L; Michel, T; Valvin, P; Edgar, J H; Cassabois, G; Gil, B

2018-02-01

Hexagonal boron nitride is a model lamellar compound where weak, non-local van der Waals interactions ensure the vertical stacking of two-dimensional honeycomb lattices made of strongly bound boron and nitrogen atoms. We study the isotope engineering of lamellar compounds by synthesizing hexagonal boron nitride crystals with nearly pure boron isotopes ( 10 B and 11 B) compared to those with the natural distribution of boron (20 at% 10 B and 80 at% 11 B). On the one hand, as with standard semiconductors, both the phonon energy and electronic bandgap varied with the boron isotope mass, the latter due to the quantum effect of zero-point renormalization. On the other hand, temperature-dependent experiments focusing on the shear and breathing motions of adjacent layers revealed the specificity of isotope engineering in a layered material, with a modification of the van der Waals interactions upon isotope purification. The electron density distribution is more diffuse between adjacent layers in 10 BN than in 11 BN crystals. Our results open perspectives in understanding and controlling van der Waals bonding in layered materials.

Social relations and breath odour.

PubMed

McKeown, L

2003-11-01

In this retrospective qualitative study, the researcher reviewed 55 client records of The Breath Odour Clinic. The purpose was to determine if individuals attended a clinic specialised in treating oral malodour for medical or social reasons. The study focused on the psychosocial and breath odour history. Clients had agreed to the use of information for research purposes. Society uses odour as a means to define and interact with the world. The olfactory, smelling experience is intimate, emotionally charged and connects us with the world. It follows that the smell from mouth breath odour can connect or disconnect a person from their social environment and intimate relationships. How one experiences one's own body is very personal and private but also very public. Breath odour is public as it occurs within a social and cultural context and personal as it affects one's body image and self-confidence. Body image, self-image and social relations mesh, interact and impact upon each other. Breath odour is a dynamic and interactive aspect of the self-image. In addition, breath odour may be value-coded as 'bad'. In 75% of the cases reviewed, decreased self-confidence and insecurity in social and intimate relations led clients to seek treatment at the specialised breath odour clinic. Their doctor, dental hygienist or dentist had treated medical and oral conditions but not resolved their breath odour problem. When a person perceives a constant bad breath problem, she/he uses defence techniques, and may avoid social situations and social relations. This affects a person's well-being.

Measurement of fatigue following 18 msw dry chamber dives breathing air or enriched air nitrox.

PubMed

Harris, R J D; Doolette, D J; Wilkinson, D C; Williams, D J

2003-01-01

Many divers report less fatigue following diving breathing oxygen rich N2-O2 mixtures compared with breathing air. In this double blinded, randomized controlled study 11 divers breathed either air or Enriched Air Nitrox 36% (oxygen 36%, nitrogen 64%) during an 18 msw (281 kPa(a)) dry chamber dive for a bottom time of 40 minutes. Two periods of exercise were performed during the dive. Divers were assessed before and after each dive using the Multidimensional Fatigue Inventory-20, a visual analogue scale, Digit Span Tests, Stroop Tests, and Divers Health Survey (DHS). Diving to 18m produced no measurable difference in fatigue, attention levels, ability to concentrate or DHS scores, following dives using either breathing gas.

The effect of radioactive iodine treatment on 14C urea breath test results in patients with hyperthyroidism.

PubMed

Arduc, Ayse; Dogan, Bercem Aycicek; Ozuguz, Ufuk; Tuna, Mazhar Muslim; Gokay, Ferhat; Tutuncu, Yasemin Ates; Isik, Serhat; Aydin, Yusuf; Peksoy, Irfan; Berker, Dilek; Guler, Serdar

2014-12-01

Radioactive Iodine therapy (RAIT) plays a major role in the treatment of hyperthyroidism. In addition to the thyroid gland, significant amounts of radioactive iodine are maintained in the stomach. The aim of this study was to determine if RAIT has any effect on Helicobacter pylori infection, based on the C urea breath test (UBT). The study included 85 patients with hyperthyroidism scheduled to undergo RAIT and 69 hyperthyroid subjects in whom methimazole treatment was planned. All subjects had pretreatment-positive UBT results, and the test was repeated on the first and third months after RAIT and methimazole treatment. After a mean RAIT dose of 15 mCi (range, 10-20 mCi), UBT became negative in 13 (15.3%) of 85 patients on the first month and 18 (21.2%) of 85 patients on the third month. All subjects treated with methimazole remained UBT positive on the first and third months of methimazole treatment (100%). Reduction in the number of UBT-positive patients on both the first and the third months after RAIT was statistically significant (P < 0.001). Distribution of hyperthyroidism etiologies and thyroid autoantibody levels in subjects with UBT that became negative and in subjects with UBT that remained positive were similar in the RAIT group (P > 0.05). Urea breath test negativity rates did not differ according to the radioiodine dose. Our findings indirectly showed that RAIT might have an antimicrobial effect on H. pylori. Clinical applications of this beneficial effect of RAIT on H. pylori should be further evaluated.

How to deal with morning bad breath: A randomized, crossover clinical trial

PubMed Central

Oliveira-Neto, Jeronimo M.; Sato, Sandra; Pedrazzi, Vinícius

2013-01-01

Context: The absence of a protocol for the treatment of halitosis has led us to compare mouthrinses with mechanical oral hygiene procedures for treating morning breath by employing a hand-held sulfide monitor. Aims: To compare the efficacy of five modalities of treatment for controlling morning halitosis in subjects with no dental or periodontal disease. Settings and Design: This is a five-period, randomized, crossover clinical trial. Materials and Methods: Twenty volunteers were randomly assigned to the trial. Testing involved the use of a conventional tongue scraper, a tongue scraper joined to the back of a toothbrush's head, two mouthrinses (0.05% cetylpyridinium chloride and 0.12% chlorhexidine digluconate) and a soft-bristled toothbrush and fluoride toothpaste for practicing oral hygiene. Statistical Analysis Used: Data analysis was performed using SPSS version 17 for Windows and NCSS 2007 software (P < 0.05). The products and the periods were compared with each other using the Friedman's test. When significant differences (P < 0.05) were determined, the products and periods were compared in pairs by using the Wilcoxon's test and by adjusting the original significance level (0.05) for multiple comparisons by using the Bonferroni's method. Results: The toothbrush's tongue scraper was able to significantly reduce bad breath for up to 2 h. Chlorhexidine reduced bad breath only at the end of the second hour, an effect that lasted for 3 h. Conclusions: Mechanical tongue cleaning was able to immediately reduce bad breath for a short period, whereas chlorhexidine and mechanical oral hygiene reduced bad breath for longer periods, achieving the best results against morning breath. PMID:24554886

Breath Analysis Using Laser Spectroscopic Techniques: Breath Biomarkers, Spectral Fingerprints, and Detection Limits

PubMed Central

Wang, Chuji; Sahay, Peeyush

2009-01-01

Breath analysis, a promising new field of medicine and medical instrumentation, potentially offers noninvasive, real-time, and point-of-care (POC) disease diagnostics and metabolic status monitoring. Numerous breath biomarkers have been detected and quantified so far by using the GC-MS technique. Recent advances in laser spectroscopic techniques and laser sources have driven breath analysis to new heights, moving from laboratory research to commercial reality. Laser spectroscopic detection techniques not only have high-sensitivity and high-selectivity, as equivalently offered by the MS-based techniques, but also have the advantageous features of near real-time response, low instrument costs, and POC function. Of the approximately 35 established breath biomarkers, such as acetone, ammonia, carbon dioxide, ethane, methane, and nitric oxide, 14 species in exhaled human breath have been analyzed by high-sensitivity laser spectroscopic techniques, namely, tunable diode laser absorption spectroscopy (TDLAS), cavity ringdown spectroscopy (CRDS), integrated cavity output spectroscopy (ICOS), cavity enhanced absorption spectroscopy (CEAS), cavity leak-out spectroscopy (CALOS), photoacoustic spectroscopy (PAS), quartz-enhanced photoacoustic spectroscopy (QEPAS), and optical frequency comb cavity-enhanced absorption spectroscopy (OFC-CEAS). Spectral fingerprints of the measured biomarkers span from the UV to the mid-IR spectral regions and the detection limits achieved by the laser techniques range from parts per million to parts per billion levels. Sensors using the laser spectroscopic techniques for a few breath biomarkers, e.g., carbon dioxide, nitric oxide, etc. are commercially available. This review presents an update on the latest developments in laser-based breath analysis. PMID:22408503

Lack of inhibitory effect of cimetidine on caffeine metabolism in children using the caffeine breath test

PubMed Central

Parker, A.C.; Pritchard, P.; Preston, T.; Dalzell, A.M.; Choonara, I.

1997-01-01

Aims To study the potential drug interaction between cimetidine and caffeine in a group of children who received cimetidine for gastritis. Methods The caffeine breath test was carried out prior to the administration of cimetidine and after 2–3 weeks therapy. The children (n=1) received 300–800 mg cimetidine daily (11–36 mg kg−1 day−1 ). Results There was no significant change in the 2 h cumulative labelled CO2 following the administration of cimetidine (mean values 5.61% before and 4.87% during cimetidine; Student’s t-test P >0.2). Conclusions Cimetidine did not have an inhibitory effect on the metabolism of caffeine in this group of children studied. PMID:9159560

Minimizing Shortness of Breath

MedlinePlus

... and hyperventilation as well as factors like emotional stress, overexertion, habitual postures and exposure to environmental irritants. Pursed-Lip Breathing One focus of occupational therapy is to teach pursed-lip breathing. This ...

Reconstruction of the Nd isotope composition of seawater on epicontinental seas: Testing the potential of Fe-Mn oxyhydroxide coatings on foraminifera tests for deep-time investigations

NASA Astrophysics Data System (ADS)

Charbonnier, Guillaume; Pucéat, Emmanuelle; Bayon, Germain; Desmares, Delphine; Dera, Guillaume; Durlet, Christophe; Deconinck, Jean-François; Amédro, Francis; Gourlan, Alexandra T.; Pellenard, Pierre; Bomou, Brahimsamba

2012-12-01

The Fe-Mn oxide fraction leached from deep-sea sediments has been increasingly used to reconstruct the Nd isotope composition of deep water masses, that can be used to track changes in oceanic circulation with a high temporal resolution. Application of this archive to reconstruct the Nd isotope composition of bottom seawater in shallow shelf environments remained however to be tested. Yet as the Nd isotope composition of seawater on continental margins is particularly sensitive to changes in erosional inputs, establishment of neritic seawater Nd isotope evolution around areas of deep water formation would be useful to discriminate the influence of changes in oceanic circulation and in isotopic composition of erosional inputs on the Nd isotope record of deep waters. The purpose of this study is to test the potential of Fe-Mn coatings leached from foraminifera tests to reconstruct the Nd isotope composition of seawater in shelf environments for deep-time intervals. Albian to Turonian samples from two different outcrops have been recovered, from the Paris Basin (Wissant section, northern France) and from the Western Interior Seaway (Hot Spring, South Dakota, USA), that were deposited in epicontinental seas. Rare Earth Element (REE) spectra enriched in middle REEs in the foraminifera leach at Wissant highlight the presence of Fe-Mn oxides. The similarity of the Nd isotopic signal of the Fe-Mn oxide fraction leached from foraminifera tests with that of fish teeth suggests that Fe-Mn oxides coating foraminifera can be good archives of shelf bottom seawater Nd isotopic composition. Inferred bottom shelf water Nd isotope compositions at Wissant range from -8.5 to -9.7 ɛ-units, about 1.5-2 ɛ-units higher than that of the contemporaneous local detrital fraction. At Hot Spring, linear REE spectra characterizing foraminifera leach may point to an absence of authigenic marine Fe-Mn oxide formation in this area during the Late Cenomanian-Early Turonian, consistent with dysoxic

Mg/Ca, Sr/Ca and Ca isotope ratios in benthonic foraminifers related to test structure, mineralogy and environmental controls

NASA Astrophysics Data System (ADS)

Gussone, Nikolaus; Filipsson, Helena L.; Kuhnert, Henning

2016-01-01

We analysed Mg/Ca, Sr/Ca and Ca isotope ratios of benthonic foraminifers from sediment core tops retrieved during several research cruises in the Atlantic Ocean, in order to improve the understanding of isotope fractionation and element partitioning resulting from biomineralisation processes and changes in ambient conditions. Species include foraminifers secreting tests composed of hyaline low magnesium calcite, porcelaneous high magnesium calcite as well as aragonite. Our results demonstrate systematic isotope fractionation and element partitioning patterns specific for these foraminiferal groups. Calcium isotope fractionation is similar in porcelaneous and hyaline calcite tests and both groups demonstrate the previously described anomaly with enrichment of heavy isotopes around 3-4 °C (Gussone and Filipsson, 2010). Calcium isotope ratios of the aragonitic species Hoeglundina elegans, on the other hand, are about 0.4‰ lighter compared to the calcitic species, which is in general agreement with stronger fractionation in inorganic aragonite compared to calcite. However, the low and strongly variable Sr content suggests additional processes during test formation, and we propose that transmembrane ion transport or a precursor phase to aragonite may be involved. Porcelaneous tests, composed of high Mg calcite, incorporate higher amounts of Sr compared to hyaline low Mg calcite, in agreement with inorganic calcite systematics, but also porcelaneous tests with reduced Mg/Ca show high Sr/Ca. While calcium isotopes, Sr/Ca and Mg/Ca in benthonic foraminifers primarily appear to fractionate and partition with a dominant inorganic control, δ44/40Ca temperature and growth rate dependencies of benthonic foraminifer tests favour a dominant contribution of light Ca by transmembrane transport relative to unfractionated seawater Ca to the calcifying fluid, thus controlling the formation of foraminiferal δ44/40Ca and Sr/Ca proxy signals.

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

Respiratory mechanics and breathing pattern in the neonatal foal.

PubMed

Koterba, A M; Kosch, P C

1987-01-01

Breathing pattern, respiratory muscle activation pattern, lung volumes and volume-pressure characteristics of the respiratory system of normal, term, neonatal foals on Days 2 and 7 of age were determined to test the hypothesis that the foal actively maintains end-expiratory lung volume (EEV) greater than the relaxation volume of the respiratory system (Vrx) because of a highly compliant chest wall. Breathing pattern was measured in the awake, unsedated foal during quiet breathing in lateral and standing positions. The typical neonatal foal breathing pattern was characterized by a monophasic inspiratory and expiratory flow pattern. Both inspiration and expiration were active, with onset of Edi activity preceding onset of inspiratory flow, and phasic abdominal muscle activity detectable throughout most of expiration. No evidence was found to support the hypothesis that the normal, term neonatal foal actively maintains EEV greater than Vrx. In the neonatal foal, normalized lung volume and lung compliance values were similar to those reported for neonates of other species, while normalized chest wall compliance was considerably lower. We conclude that the chest wall of the term neonatal foal is sufficiently rigid to prevent a low Vrx. This characteristic probably prevents the foal from having to use a breathing strategy which maintains an EEV greater than Vrx.

How Important Is a Reproducible Breath Hold for Deep Inspiration Breath Hold Breast Radiation Therapy?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wiant, David, E-mail: David.wiant@conehealth.com; Wentworth, Stacy; Liu, Han

Purpose: Deep inspiration breath hold (DIBH) for left-sided breast cancer has been shown to reduce heart dose. Surface imaging helps to ensure accurate breast positioning, but it does not guarantee a reproducible breath hold (BH) at DIBH treatments. We examine the effects of variable BH positions for DIBH treatments. Methods and Materials: Twenty-five patients who underwent free breathing (FB) and DIBH scans were reviewed. Four plans were created for each patient: FB, DIBH, FB-DIBH (the DIBH plans were copied to the FB images and recalculated, and image registration was based on breast tissue), and P-DIBH (a partial BH with themore » heart shifted midway between the FB and DIBH positions). The FB-DIBH plans give a “worst-case” scenario for surface imaging DIBH, where the breast is aligned by surface imaging but the patient is not holding their breath. Kolmogorov-Smirnov tests were used to compare the dose metrics. Results: The DIBH plans gave lower heart dose and comparable breast coverage versus FB in all cases. The FB-DIBH plans showed no significant difference versus FB plans for breast coverage, mean heart dose, or maximum heart dose (P≥.10). The mean heart dose differed between FB-DIBH and FB by <2 Gy for all cases, and the maximum heart dose differed by <2 Gy for 21 cases. The P-DIBH plans showed significantly lower mean heart dose than FB (P<.01). The mean heart doses for the P-DIBH plans were« less

Detection of Δ9-tetrahydrocannabinol in exhaled breath collected from cannabis users.

PubMed

Beck, Olof; Sandqvist, Sören; Dubbelboer, Ilse; Franck, Johan

2011-10-01

Exhaled breath has recently been proposed as a new possible matrix for drugs of abuse testing. A key drug is cannabis, and the present study was aimed at investigating the possibility of detecting tetrahydrocannabinol and tetrahydrocannabinol carboxylic acid in exhaled breath after cannabis smoking. Exhaled breath was sampled from 10 regular cannabis users and 8 controls by directing the exhaled breath by suction through an Empore C(18) disk. The disk was extracted with hexane/ethyl acetate, and the resulting extract was evaporated to dryness and redissolved in 100 μL hexane/ethyl acetate. A 3-μL aliquot was injected onto the LC-MS-MS system and analyzed using positive electrospray ionization and selected reaction monitoring. In samples collected 1-12 h after cannabis smoking, tetrahydrocannabinol was detected in all 10 subjects. The rate of excretion was between 9.0 and 77.3 pg/min. Identification of tetrahydrocannabinol was based on correct retention time relative to tetrahydrocannabinol-d(3) and correct product ion ratio. In three samples, peaks were observed for tetrahydrocannabinol carboxylic acid, but these did not fulfill identification criteria. Neither tetrahydrocannabinol or tetrahydrocannabinol carboxylic acid was detected in the controls. These results confirm older reports that tetrahydrocannabinol is present in exhaled breath following cannabis smoking and extend the detection time from minutes to hours. The results further support the idea that exhaled breath is a promising matrix for drugs-of-abuse testing.

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

Endogenous CO dynamics monitoring in breath by tunable diode laser

NASA Astrophysics Data System (ADS)

Kouznetsov, Andrian I.; Stepanov, Eugene V.; Shulagin, Yurii A.; Skrupskii, Vladimir A.

1996-04-01

High sensitive CO gas analyzer based on tunable diode laser (TDL) was used as a real time monitor of endogenous carbon monoxide in a set of breath physiology experiments. The measurements of the CO content dynamics in exhaled air with 10 ppb sensitivity were attended with detection of carbon dioxide and O2 in breath, lung ventilation parameters, heart rate and blood analysis using conventional techniques. Variations of endogenous CO in human breath caused by hyperoxia, hypoxia, hyperventilation as well as sport loading were studied in real time. Scattering of the CO variation time constants was observed for different tested persons. Possible reasons for this scattering related with the organisms' physiology peculiarities are discussed.

Do elite breath-hold divers suffer from mild short-term memory impairments?

PubMed

Billaut, François; Gueit, Patrice; Faure, Sylvane; Costalat, Guillaume; Lemaître, Frédéric

2018-03-01

Repeated apneas are associated with severe hypoxemia that may ultimately lead to loss of consciousness in some breath-hold divers. Despite increasing number of practitioners, the relationship between apnea-induced hypoxia and neurocognitive functions is still poorly understood in the sport of free diving. To shed light onto this phenomenon, we examined the impact of long-term breath-hold diving training on attentional processing, short-term memory, and long-term mnesic and executive functions. Thirty-six men matched for age, height, and weight were separated into the following 3 groups: (i) 12 elite breath-hold divers (EBHD), mean static apnea best time 371 s, 105 months mean apnea experience; (ii) 12 novice breath-hold divers, mean best time 243 s, 8.75 months mean apnea experience; and (iii) 12 physical education students with no breath-hold diving experience; all of these participants performed varied written and computerized neuropsychological tasks. Compared with the 2 other groups, the EBHD group was slower to complete the interference card during a Stroop test (F [1,33] = 4.70, p < 0.05), and presented more errors on the interference card (F [1,33] = 2.96, p < 0.05) and a lower total interference score (F [1,33] = 5.64, p < 0.05). The time to complete the interference card test was positively correlated with maximal static apnea duration (r = 0.73, p < 0.05) and the number of years of breath-hold diving training (r = 0.79, p < 0.001). These findings suggest that breath-hold diving training over several years may cause mild, but persistent, short-term memory impairments.

A Test of Carbon and Oxygen Stable Isotope Ratio Process Models in Tree Rings.

NASA Astrophysics Data System (ADS)

Roden, J. S.; Farquhar, G. D.

2008-12-01

Stable isotopes ratios of carbon and oxygen in tree ring cellulose have been used to infer environmental change. Process-based models have been developed to clarify the potential of historic tree ring records for meaningful paleoclimatic reconstructions. However, isotopic variation can be influenced by multiple environmental factors making simplistic interpretations problematic. Recently, the dual isotope approach, where the variation in one stable isotope ratio (e.g. oxygen) is used to constrain the interpretation of variation in another (e.g. carbon), has been shown to have the potential to de-convolute isotopic analysis. However, this approach requires further testing to determine its applicability for paleo-reconstructions using tree-ring time series. We present a study where the information needed to parameterize mechanistic models for both carbon and oxygen stable isotope ratios were collected in controlled environment chambers for two species (Pinus radiata and Eucalyptus globulus). The seedlings were exposed to treatments designed to modify leaf temperature, transpiration rates, stomatal conductance and photosynthetic capacity. Both species were grown for over 100 days under two humidity regimes that differed by 20%. Stomatal conductance was significantly different between species and for seedlings under drought conditions but not between other treatments or humidity regimes. The treatments produced large differences in transpiration rate and photosynthesis. Treatments that effected photosynthetic rates but not stomatal conductance influenced carbon isotope discrimination more than those that influenced primarily conductance. The various treatments produced a range in oxygen isotope ratios of 7 ‰. Process models predicted greater oxygen isotope enrichment in tree ring cellulose than observed. The oxygen isotope ratios of bulk leaf water were reasonably well predicted by current steady-state models. However, the fractional difference between models that

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.

Traveling with breathing problems

MedlinePlus

... obstructive lung disease - travel; Chronic bronchitis - travel; Emphysema - travel ... you: Are short of breath most of the time Get short of breath ... doctor if you plan to travel in a place at a high altitude (such ...

High-pitched breath sounds indicate airflow limitation in asymptomatic asthmatic children.

PubMed

Habukawa, Chizu; Nagasaka, Yukio; Murakami, Katsumi; Takemura, Tsukasa

2009-04-01

Asthmatic children may have airway dysfunction even when asymptomatic, indicating that their long-term treatment is less than optimal. Although airway dysfunction can be identified on lung function testing, performing these tests can be difficult in infants. We studied whether breath sounds reflect subtle airway dysfunction in asthmatic children. The highest frequency of inspiratory breaths sounds (HFI) and the highest frequency of expiratory breath sounds (HFE) were measured in 131 asthmatic children while asymptomatic and with no wheezes for more than 2 weeks. No child was being treated with inhaled corticosteroids (ICS). Breath sounds were recorded and analysed by sound spectrography and compared with spirometric parameters. After initial evaluation, cases with more than step 2 (mild persistent) asthma were treated using inhaled fluticasone (100-200 microg/day) for 1 month, and then breath sound analysis and pulmonary function testing were repeated. On initial evaluation, HFI correlated with the percentage of predicted FEF(50) (%FEF(50)), (r = -0.45, P < 0.001), the percentage of predicted FEF(75) (%FEF(75)) (r = -0.456, P < 0.001), and FEV(1) as a percentage of FVC (FEV(1)/FVC (%)) (r = -0.32, P < 0.001). HFI did not correlate with the percentage of predicted PEF (%PEF). The 69 children with lower than normal %FEF(50) were then treated with ICS. The %FEF(50) and %FEF(75) improved after ICS treatment, and increases in %FEF(50) (P < 0.005) correlated with decreases in HFI (P < 0.001). Higher HFI in asymptomatic asthmatic children may indicate small airway obstruction. Additional ICS treatment may improve the pulmonary function indices representing small airway function with simultaneous HFI decreases in such patients.

Probing plasmonic breathing modes optically

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krug, Markus K., E-mail: markus.krug@uni-graz.at; Reisecker, Michael; Hohenau, Andreas

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.

Effect of upper costal and costo-diaphragmatic breathing types on electromyographic activity of respiratory muscles.

PubMed

Celhay, Isabel; Cordova, Rosa; Miralles, Rodolfo; Meza, Francisco; Erices, Pia; Barrientos, Camilo; Valenzuela, Saúl

2015-04-01

To compare electromyographic (EMG) activity in young-adult subjects with different breathing types. This study included 50 healthy male subjects with complete natural dentition, and no history of orofacial pain or craniomandibular-cervical-spinal disorders. Subjects were classified into two groups: upper costal breathing type, and costo-diaphragmatic breathing. Bipolar surface electrodes were located on sternocleidomastoid, diaphragm, external intercostal, and latissimus dorsi muscles. Electromyographic activity was recorded during the following tasks: (1) normal quiet breathing; (2) speaking the word 'Mississippi'; (3) swallowing saliva; and (4) forced deep breathing. Sternocleidomastoid and latissimus dorsi EMG activity was not significantly different between breathing types, whereas diaphragm and external intercostal EMG activity was significantly higher in the upper costal than costo-diaphragmatic breathing type in all tasks (P<0·05; Wilcoxon signed rank-sum test). Diaphragm and external intercostal EMG activity suggests that there could be differences in motor unit recruitment strategies depending on the breathing type.

Testing plant use of mobile vs immobile soil water sources using stable isotope experiments.

PubMed

Vargas, Ana I; Schaffer, Bruce; Yuhong, Li; Sternberg, Leonel da Silveira Lobo

2017-07-01

We tested for isotope exchange between bound (immobile) and mobile soil water, and whether there is isotope fractionation during plant water uptake. These are critical assumptions to the formulation of the 'two water worlds' hypothesis based on isotope profiles of soil water. In two different soil types, soil-bound water in two sets of 19-l pots, each with a 2-yr-old avocado plant (Persea americana), were identically labeled with tap water. After which, one set received isotopically enriched water whereas the other set received tap water as the mobile phase water. After a dry down period, we analyzed plant stem water as a proxy for soil-bound water as well as total soil water by cryogenic distillation. Seventy-five to 95% of the bound water isotopically exchanged with the mobile water phase. In addition, plants discriminated against 18 O and 2 H during water uptake, and this discrimination is a function of the soil water loss and soil type. The present experiment shows that the assumptions for the 'two water worlds' hypothesis are not supported. We propose a novel explanation for the discrepancy between isotope ratios of the soil water profile and other water compartments in the hydrological cycle. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

Identification of risk factors for pancreatic exocrine insufficiency after pancreaticoduodenectomy using a 13C-labeled mixed triglyceride breath test.

PubMed

Hirono, Seiko; Murakami, Yoshiaki; Tani, Masaji; Kawai, Manabu; Okada, Ken-ichi; Uemura, Kenichiro; Sudo, Takeshi; Hashimoto, Yasushi; Nakagawa, Naoya; Kondo, Naru; Yamaue, Hiroki

2015-02-01

There are only a few reports concerning long-term exocrine function after pancreaticoduodenectomy (PD), although the number of long-term survivors has increased. We assessed pancreatic exocrine function after PD in 189 patients to identify risk factors for pancreatic exocrine insufficiency. We evaluated patients' exocrine function by using the (13)C-labeled mixed triglyceride breath test, a noninvasive test feasible in outpatient service units. The present study included 99 patients that underwent pancreaticojejunostomy (PJ) at Wakayama Medical University Hospital and 90 patients that underwent pancreaticogastrostomy (PG) at Hiroshima University Hospital, the standard reconstruction techniques during PD at the respective hospitals. We also analyzed long-term morphological changes of remnant pancreas by computed tomography (main pancreatic duct dilation and parenchymal atrophy), nutritional status, and endocrine function. Independent risk factors for exocrine insufficiency after PD include hard pancreas (P = 0.003, odds ratio; 3.157) and PG reconstruction (P = 0.040, odds ratio; 2.321). Breath test results correlated significantly with post-operative morphological changes, nutritional status, and endocrine function. Atrophic changes of the remnant pancreas in the PG group were more severe than those in the PJ group. Furthermore, for patients with a soft pancreas, postoperative body weight changes, prognostic nutritional index, serum total protein levels as well as exocrine test were worse in the PG group, compared with the PJ group. Our results showed that PJ reconstruction might be superior to PG during PD, from the viewpoint of long-term pancreatic exocrine function, although further prospective studies are needed.

Procedures in the 13C octanoic acid breath test for measurement of gastric emptying: analysis using Bland-Altman methods.

PubMed

Clegg, Miriam E; Shafat, Amir

2010-08-01

The (13)C octanoic acid breath test (OBT) was first developed as an alternative method of measuring gastric emptying (GE) to scintigraphy. There has been much debate about the test duration and how often measurements need to be taken. This study aims to address these issues. For 78 GE tests using the (13)C OBT, GE lag phase (T(lag)) was calculated while sampling more frequently than the recommended every 15 min. Comparisons between T(lag) were completed using Bland-Altman plots. Similarly, 4 or 6 h test durations were assessed to establish if they yield the same GE half time (T(half)). From one volunteer, samples were taken every 1 min for the first 30 min and then every 15 min until 6 h. GE times were then calculated using different combinations of sampling times. Evidence of a visible T(lag) was also explored from this data. Findings indicated that taking samples every 5 min for the first 30 min instead of every 15 min did not change the GE T(lag) based on Bland-Altman plots. The correlation between these two methods was also high (r(2) = 0.9957). The findings showed that the difference between the two sampling durations 4 and 6 h was large and the correlation between the methods was low (r(2) = 0.8335). Samples taken at a rate of one breath per min indicated lack of a visible T(lag). Sampling for the (13)C OBT should be completed every 15 min for 6 h.

NICMOS Focus and HST Breathing

NASA Astrophysics Data System (ADS)

Suchkov, A.; Hershey, J.

1998-09-01

The program 7608 monitored on a biweekly basis NICMOS camera foci from June 9, 1997, through February 18, 1998. Each of the biweekly observations included 17 measurements of focus position (focus sweeps), individually for each of the three cameras. The measurements for camera 1 and camera 3 foci covered one or two HST orbital periods. Comparison of these measurements with the predictions of the three OTA focus breathing models has shown the following. (1). Focus variations seen in NICMOS focus sweeps correlate well with the OTA focus thermal breathing as predicted by breathing models (“4- temperature”, “full-temperature”, and “attitude” models). Thus they can be attributed mostly to the HST orbital temperature variation. (2). The amount of breathing (breathing amplitude) has been found to be on average larger in the first orbit after a telescope slew to a new target. This is explained as being due to additional thermal perturbations caused by the change in the HST attitude as the telescope repoints to a new target. (3). In the first orbit, the amount of focus change predicted by the 4-temperature model is about the same as that seen in the focus sweeps data (breathing scale factor ~1). However the full-temperature model predicts a two times smaller breathing amplitude (breathing scale factor ~1.7). This suggests that the light shield temperatures are more responsive to the attitude change than temperatures from the other temperature sensors. The results of this study may help to better understand the HST thermal cycles and to improve the models describing the impact of those on both the OTA and NICMOS focus.

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.

Drinking influences exhaled breath condensate acidity.

PubMed

Kullmann, Tamás; Barta, Imre; Antus, Balázs; Horváth, Ildikó

2008-01-01

Exhaled breath condensate analysis is a developing method for investigating airway pathology. Impact of food and drink on breath condensate composition has not been systematically addressed. The aim of the study was to follow exhaled breath condensate pH after drinking an acidic and a neutral beverage. Breath condensate, capillary blood, and urine of 12 healthy volunteers were collected before and after drinking either 1 l of coke or 1 l of mineral water. The pH of each sample was determined with a blood gas analyzer. The mean difference between the pH of two breath condensate samples collected within 15 min before drinking was 0.13+/-0.03. Condensate pH decreased significantly from 6.29+/-0.02 to 6.24+/-0.02 (p<0.03) after drinking coke and from 6.37+/-0.03 to 6.22+/-0.04 (p<0.003) after drinking water. Drinking coke induced significant changes in blood and urine pH as well. Drinking influences exhaled breath condensate composition and may contribute to the variability of exhaled breath condensate pH.

SU-E-T-326: The Oxygen Saturation (SO2) and Breath-Holding Time Variation Applied Active Breathing Control (ABC)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gong, G; Yin, Y

Purpose: To study the oxygen saturation (SO2) and breath-holding time variation applied active breathing control (ABC) in radiotherapy of tumor. Methods: 24 volunteers were involved in our trials, and they all did breath-holding motion assisted by ELEKTA Active Breathing Coordinator 2.0 for 10 times respectively. And the patient monitor was used to observe the oxygen saturation (SO2) variation. The variation of SO2, and length of breath-holding time and the time for recovering to the initial value of SO2 were recorded and analyzed. Results: (1) The volunteers were divided into two groups according to the SO2 variation in breath-holding: A group,more » 14 cases whose SO2 reduction were more than 2% (initial value was 97% to 99%, while termination value was 91% to 96%); B group, 10 cases were less than 2% in breath-holding without inhaling oxygen. (2) The interfraction breath holding time varied from 8 to 20s for A group compared to the first breath-holding time, and for B group varied from 4 to 14s. (3) The breathing holding time of B group prolonged mean 8s, compared to A group. (4) The time for restoring to the initial value of SO2 was from 10s to 30s. And the breath-holding time shortened obviously for patients whose SO2 did not recover to normal. Conclusion: It is very obvious that the SO2 reduction in breath-holding associated with ABC for partial people. It is necessary to check the SO2 variation in breath training, and enough time should be given to recover SO2.« less

Pulmonary Function Testing in Children

MedlinePlus

... breathing test. About 15 minutes after taking the medicine, your child will repeat the breathing test. The results from ... the first test to find out if the medicine has improved your child’s breathing. Why shouldn’t I give my child ...

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. Published by Elsevier Ltd.

Electromyographic fatigue of orbicular oris muscles during exercises in mouth and nasal breathing children.

PubMed

Busanello-Stella, Angela Ruviaro; Blanco-Dutra, Ana Paula; Corrêa, Eliane Castilhos Rodrigues; Silva, Ana Maria Toniolo da

2015-01-01

To investigate the process of fatigue in orbicularis oris muscles by analyzing the median frequency of electromyographic signal and the referred fatigue time, according to the breathing mode and the facial pattern. The participants were 70 children, aged 6 to 12 years, who matched the established criteria. To be classified as 36 nasal-breathing and 34 mouth-breathing children, they underwent speech-language, otorhinolaryngologic, and cephalometric evaluation. For the electromyographic assessment, the children had to sustain lip dumbbells weighing 40, 60, and 100 g and a lip exerciser, until the feeling of fatigue. Median frequency was analyzed in 5, 10, 15, and 20 seconds of activity. The referred time of the feeling of fatigue was also recorded. Data were analyzed through the analysis of variance--repeated measures (post hoc Tukey's test), Kruskal-Wallis test, and Mann-Whitney U-test. A significant decrease in the median frequency from 5 seconds of activity was observed, independently from the comparison between the groups. On comparison, the muscles did not show significant decrease. The reported time for the feeling of fatigue was shorter for mouth-breathing individuals. This feeling occurred after the significant decrease in the median frequency. There were signals that indicated myoelectric fatigue for the orbicularis oris muscles, in both groups analyzed, from the first 5 seconds of activity. Myoelectric fatigue in the orbicularis oris muscles preceded the reported feeling of fatigue in all groups. The account for fatigue time was influenced by only the breathing pattern, occurring more precociously in mouth-breathing children.

Improved workflow for quantification of left ventricular volumes and mass using free-breathing motion corrected cine imaging.

PubMed

Cross, Russell; Olivieri, Laura; O'Brien, Kendall; Kellman, Peter; Xue, Hui; Hansen, Michael

2016-02-25

Traditional cine imaging for cardiac functional assessment requires breath-holding, which can be problematic in some situations. Free-breathing techniques have relied on multiple averages or real-time imaging, producing images that can be spatially and/or temporally blurred. To overcome this, methods have been developed to acquire real-time images over multiple cardiac cycles, which are subsequently motion corrected and reformatted to yield a single image series displaying one cardiac cycle with high temporal and spatial resolution. Application of these algorithms has required significant additional reconstruction time. The use of distributed computing was recently proposed as a way to improve clinical workflow with such algorithms. In this study, we have deployed a distributed computing version of motion corrected re-binning reconstruction for free-breathing evaluation of cardiac function. Twenty five patients and 25 volunteers underwent cardiovascular magnetic resonance (CMR) for evaluation of left ventricular end-systolic volume (ESV), end-diastolic volume (EDV), and end-diastolic mass. Measurements using motion corrected re-binning were compared to those using breath-held SSFP and to free-breathing SSFP with multiple averages, and were performed by two independent observers. Pearson correlation coefficients and Bland-Altman plots tested agreement across techniques. Concordance correlation coefficient and Bland-Altman analysis tested inter-observer variability. Total scan plus reconstruction times were tested for significant differences using paired t-test. Measured volumes and mass obtained by motion corrected re-binning and by averaged free-breathing SSFP compared favorably to those obtained by breath-held SSFP (r = 0.9863/0.9813 for EDV, 0.9550/0.9685 for ESV, 0.9952/0.9771 for mass). Inter-observer variability was good with concordance correlation coefficients between observers across all acquisition types suggesting substantial agreement. Both motion

Breath alcohol analyzer mistakes methanol poisoning for alcohol intoxication.

PubMed

Caravati, E Martin; Anderson, Kathleen T

2010-02-01

Breath alcohol analyzers are used to detect ethanol in motorists and others suspected of public intoxication. One concern is their ability to detect interfering substances that may falsely increase the ethanol reading. A 47-year-old-man was found in a public park, acting intoxicated. A breath analyzer test (Intoxilyzer 5000EN) measured 0.288 g/210 L breath ethanol, without an interferent noted. In the emergency department, the patient admitted to drinking HEET Gas-Line antifreeze, which contains 99% methanol. Two to three hours after ingestion, serum and urine toxicology screen results were negative for ethanol and multiple other substances. His serum methanol concentration was 589 mg/dL, serum osmolality 503 mOsm/kg, osmolar gap 193 mOsm/kg, and anion gap 17 mmol/L. The patient was treated with intravenous ethanol, fomepizole, and hemodialysis without complication. This is a unique clinical case of a breath alcohol analyzer reporting methanol as ethanol. Intoxilyzer devices have been shown to indicate some substances (acetone) as interferents in humans but not methanol. Increased serum concentrations of methanol can be reported as ethanol by a commonly used breath alcohol analyzer, which can result in a delayed diagnosis or misdiagnosis and subsequent methanol toxicity if antidotal treatment is not administered in a timely manner. Copyright (c) 2009 American College of Emergency Physicians. Published by Mosby, Inc. All rights reserved.

Elimination characteristics of post-operative isoflurane levels in alveolar exhaled breath via PTR-MS analysis.

PubMed

Fernández Del Río, R; O'Hara, M E; Pemberton, P; Whitehouse, T; Mayhew, C A

2016-10-12

Isoflurane (1-chloro-2,2,2-trifluoroethyl difluoromethyl ether), C 3 H 2 ClF 5 O, is a commonly used inhalation anaesthetic. Using a proton transfer reaction mass spectrometer (PTR-MS) we have detected isoflurane in the breath of patients several weeks following major surgery. That isoflurane is detected in the breath of patients so long after being anaesthetised raises questions about when cognitive function has fully returned to a patient. Temporal profiles of isoflurane concentrations in breath are presented for five patients (F/M 3/2, mean age 50 years, min-max 36-58 years) who had undergone liver transplant surgery. In addition, results from a headspace analysis of isoflurane are presented so that the product ions resulting from the reactions of H 3 O + with isoflurane in PTR-MS could be easily identified in the absence of the complex chemical environment of breath. Six product ions were identified. In order of increasing m/z (using the 35 Cl isotope where appropriate) these are [Formula: see text] (m/z 51), CHFCl + (m/z 67), CF 3 CHCl + (m/z 117), C 3 F 4 OCl + (m/z 163), C 3 H 2 F 4 OCl + (m/z 165), and C 3 F 4 OCl + H 2 O (m/z 183). No protonated parent was detected. For the headspace study both clean air and CO 2 enriched clean air (4% CO 2 ) were used as buffer gases in the drift tube of the PTR-MS. The CO 2 enriched air was used to determine if exhaled breath would affect the product ion branching ratios. Importantly no significant differences were observed, and therefore for isoflurane the product ion distributions determined in a normal air mixture can be used for breath analysis. Given that PTR-MS can be operated under different reduced electric fields (E/N), the dependence of the product ion branching percentages for isoflurane on E/N (96-138 Td) are reported.

Slow Breathing and Hypoxic Challenge: Cardiorespiratory Consequences and Their Central Neural Substrates

PubMed Central

Critchley, Hugo D.; Nicotra, Alessia; Chiesa, Patrizia A.; Nagai, Yoko; Gray, Marcus A.; Minati, Ludovico; Bernardi, Luciano

2015-01-01

Controlled slow breathing (at 6/min, a rate frequently adopted during yoga practice) can benefit cardiovascular function, including responses to hypoxia. We tested the neural substrates of cardiorespiratory control in humans during volitional controlled breathing and hypoxic challenge using functional magnetic resonance imaging (fMRI). Twenty healthy volunteers were scanned during paced (slow and normal rate) breathing and during spontaneous breathing of normoxic and hypoxic (13% inspired O2) air. Cardiovascular and respiratory measures were acquired concurrently, including beat-to-beat blood pressure from a subset of participants (N = 7). Slow breathing was associated with increased tidal ventilatory volume. Induced hypoxia raised heart rate and suppressed heart rate variability. Within the brain, slow breathing activated dorsal pons, periaqueductal grey matter, cerebellum, hypothalamus, thalamus and lateral and anterior insular cortices. Blocks of hypoxia activated mid pons, bilateral amygdalae, anterior insular and occipitotemporal cortices. Interaction between slow breathing and hypoxia was expressed in ventral striatal and frontal polar activity. Across conditions, within brainstem, dorsal medullary and pontine activity correlated with tidal volume and inversely with heart rate. Activity in rostroventral medulla correlated with beat-to-beat blood pressure and heart rate variability. Widespread insula and striatal activity tracked decreases in heart rate, while subregions of insular cortex correlated with momentary increases in tidal volume. Our findings define slow breathing effects on central and cardiovascular responses to hypoxic challenge. They highlight the recruitment of discrete brainstem nuclei to cardiorespiratory control, and the engagement of corticostriatal circuitry in support of physiological responses that accompany breathing regulation during hypoxic challenge. PMID:25973923

Optimising diffusion-weighted MR imaging for demonstrating pancreatic cancer: a comparison of respiratory-triggered, free-breathing and breath-hold techniques.

PubMed

Kartalis, Nikolaos; Loizou, Louiza; Edsborg, Nick; Segersvärd, Ralf; Albiin, Nils

2012-10-01

To compare respiratory-triggered, free-breathing, and breath-hold DWI techniques regarding (1) image quality, and (2) signal intensity (SI) and ADC measurements in pancreatic ductal adenocarcinoma (PDAC). Fifteen patients with histopathologically proven PDAC underwent DWI prospectively at 1.5 T (b = 0, 50, 300, 600 and 1,000 s/mm(2)) with the three techniques. Two radiologists, independently and blindly, assigned total image quality scores [sum of rating diffusion images (lesion detection, anatomy, presence of artefacts) and ADC maps (lesion characterisation, overall image quality)] per technique and ranked them. The lesion SI, signal-to-noise ratio, mean ADC and coefficient of variation (CV) were compared. Total image quality scores for respiratory-triggered, free-breathing and breath-hold techniques were 17.9, 16.5 and 17.1 respectively (respiratory-triggered was significantly higher than free-breathing but not breath-hold). The respiratory-triggered technique had a significantly higher ranking. Lesion SI on all b-values and signal-to-noise ratio on b300 and b600 were significantly higher for the respiratory-triggered technique. For respiratory-triggered, free-breathing and breath-hold techniques the mean ADCs were 1.201, 1.132 and 1.253 × 10(-3) mm(2)/s, and mean CVs were 8.9, 10.8 and 14.1 % respectively (respiratory-triggered and free-breathing techniques had a significantly lower mean CV than the breath-hold technique). In both analyses, respiratory-triggered DWI showed superiority and seems the optimal DWI technique for demonstrating PDAC. • Diffusion-weighted magnetic resonance imaging is increasingly used to detect pancreatic cancer • Images are acquired using various breathing techniques and multiple b-values • Breathing techniques used: respiratory-triggering, free-breathing and breath-hold • Respiratory-triggering seems the optimal breathing technique for demonstrating pancreatic cancer.

Modified Helicobacter test using a new test meal and a 13C-urea breath test in Helicobacter pylori positive and negative dyspepsia patients on proton pump inhibitors.

PubMed

Tepeš, Bojan; Malfertheiner, Peter; Labenz, Joachim; Aygen, Sitke

2017-08-28

To determine the sensitivity and specificity of the 13 C-urea breath test (UBT) in patients taking proton pump inhibitors (PPIs), using a new test meal Refex. One hundred and fourteen consecutive patients with dyspepsia, 53 Helicobacter pylori ( H. pylori ) positive, 49 H. pylori negative, were included in the study. The patients were then given esomeprazole 40 mg for 29 consecutive days, and the 13 C-UBT with the new test meal was performed the next morning. The sensitivity of the 13 C-UBT with a cut off 2.5‰ was 92.45% (95%CI: 81.79%-97.91%) by per-protocol (PP) analysis and 78.13% (95%CI: 66.03%-87.49%) by intention-to-treat (ITT) analysis. The specificity of the 13 C-UBT test was 96.00% in the ITT population (95%CI: 86.29%-99.51%) and 97.96% in the PP population (95%CI: 89.15%-99.95%). The new test meal based 13 C-UBT is highly accurate in patients on PPIs and can be used in those unable to stop their PPI treatment.

Effects of alcohol-based hand hygiene solutions on breath alcohol detection in the emergency department.

PubMed

Emerson, Beth L; Whitfill, Travis; Baum, Carl R; Garlin-Kane, Katherine; Santucci, Karen

2016-12-01

This study aimed to investigate the effects of alcohol-based hand hygiene solution (ABHS) use by care providers on point-of-care alcohol breath analyzer interpretation under different clinically relevant conditions. Among each test condition (foam vehicle with immediate testing, gel vehicle with immediate testing, allowing hands to dry after the use of ABHS, and donning gloves after the use of ABHS), alcohol was detected in breath at 1 minute after use of ABHS. Because the use of ABHS by individuals administering breath alcohol detection may result in false-positive detection of alcohol, staff using these devices should consider traditional hand hygiene with soap and water. Copyright © 2016 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

46 CFR 197.456 - Breathing supply hoses.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Breathing supply hoses. 197.456 Section 197.456 Shipping....456 Breathing supply hoses. (a) The diving supervisor shall insure that— (1) Each breathing supply....5 times its maximum working pressure; (2) Each breathing supply hose assembly, prior to being placed...

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.

A calcium isotope test of end-Permian ocean acidification using biogenic apatite

NASA Astrophysics Data System (ADS)

Hinojosa, J.; Brown, S. T.; DePaolo, D. J.; Paytan, A.; Shen, S.; Chen, J.; Payne, J.

2011-12-01

Submarine erosional truncation of uppermost Permian carbonate strata has been interpreted to reflect ocean acidification coincident with the end-Permian mass extinction. Although this scenario is consistent with carbon isotope and paleontological data, several alternative scenarios, such as ocean overturn or collapse of the biological pump, can also account for the carbon isotope and paleontological evidence. Calcium isotopes provide a geochemical proxy to test between acidification and alternative scenarios. Specifically, a negative shift in the calcium isotope composition (δ44/40Ca) of seawater is predicted under the acidification scenario but not the alternatives. The δ44/40Ca of carbonate rocks from south China exhibits a negative excursion of approximately 0.3%, but this shift could result from either a change in the δ44/40Ca of seawater or a change in carbonate mineralogy because calcite and aragonite exhibit substantially different fractionation factors relative to seawater. To test whether the negative shift in δ44/40Ca reflects seawater δ44/40Ca or carbonate mineralogy, we measured the δ44/40Ca of conodont microfossils (calcium hydroxyapatite) from the global stratotype section for the Permian-Triassic boundary at Meishan, China. The conodont δ44/40Ca record shows a negative excursion similar in stratigraphic position and magnitude to that previously observed in carbonate rocks. Parallel negative excursions in the δ44/40Ca of carbonate rocks and conodont microfossils cannot be accounted for by a change in carbonate mineralogy but are consistent with a negative shift in the δ44/40Ca of seawater. These data add further support for the ocean acidification scenario, pointing toward strong similarities between the greatest catastrophe in the history of animal life and anticipated global change during the 21st century.

Swimming in air-breathing fishes.

PubMed

Lefevre, S; Domenici, P; McKenzie, D J

2014-03-01

Fishes with bimodal respiration differ in the extent of their reliance on air breathing to support aerobic metabolism, which is reflected in their lifestyles and ecologies. Many freshwater species undertake seasonal and reproductive migrations that presumably involve sustained aerobic exercise. In the six species studied to date, aerobic exercise in swim flumes stimulated air-breathing behaviour, and there is evidence that surfacing frequency and oxygen uptake from air show an exponential increase with increasing swimming speed. In some species, this was associated with an increase in the proportion of aerobic metabolism met by aerial respiration, while in others the proportion remained relatively constant. The ecological significance of anaerobic swimming activities, such as sprinting and fast-start manoeuvres during predator-prey interactions, has been little studied in air-breathing fishes. Some species practise air breathing during recovery itself, while others prefer to increase aquatic respiration, possibly to promote branchial ion exchange to restore acid-base balance, and to remain quiescent and avoid being visible to predators. Overall, the diversity of air-breathing fishes is reflected in their swimming physiology as well, and further research is needed to increase the understanding of the differences and the mechanisms through which air breathing is controlled and used during exercise. © 2014 The Fisheries Society of the British Isles.

Fiber-enhanced Raman multigas spectroscopy: a versatile tool for environmental gas sensing and breath analysis.

PubMed

Hanf, Stefan; Keiner, Robert; Yan, Di; Popp, Jürgen; Frosch, Torsten

2014-06-03

Versatile multigas analysis bears high potential for environmental sensing of climate relevant gases and noninvasive early stage diagnosis of disease states in human breath. In this contribution, a fiber-enhanced Raman spectroscopic (FERS) analysis of a suite of climate relevant atmospheric gases is presented, which allowed for reliable quantification of CH4, CO2, and N2O alongside N2 and O2 with just one single measurement. A highly improved analytical sensitivity was achieved, down to a sub-parts per million limit of detection with a high dynamic range of 6 orders of magnitude and within a second measurement time. The high potential of FERS for the detection of disease markers was demonstrated with the analysis of 27 nL of exhaled human breath. The natural isotopes (13)CO2 and (14)N(15)N were quantified at low levels, simultaneously with the major breath components N2, O2, and (12)CO2. The natural abundances of (13)CO2 and (14)N(15)N were experimentally quantified in very good agreement to theoretical values. A fiber adapter assembly and gas filling setup was designed for rapid and automated analysis of multigas compositions and their fluctuations within seconds and without the need for optical readjustment of the sensor arrangement. On the basis of the abilities of such miniaturized FERS system, we expect high potential for the diagnosis of clinically administered (13)C-labeled CO2 in human breath and also foresee high impact for disease detection via biologically vital nitrogen compounds.

Breath-Hold Diving.

PubMed

Fitz-Clarke, John R

2018-03-25

Breath-hold diving is practiced by recreational divers, seafood divers, military divers, and competitive athletes. It involves highly integrated physiology and extreme responses. This article reviews human breath-hold diving physiology beginning with an historical overview followed by a summary of foundational research and a survey of some contemporary issues. Immersion and cardiovascular adjustments promote a blood shift into the heart and chest vasculature. Autonomic responses include diving bradycardia, peripheral vasoconstriction, and splenic contraction, which help conserve oxygen. Competitive divers use a technique of lung hyperinflation that raises initial volume and airway pressure to facilitate longer apnea times and greater depths. Gas compression at depth leads to sequential alveolar collapse. Airway pressure decreases with depth and becomes negative relative to ambient due to limited chest compliance at low lung volumes, raising the risk of pulmonary injury called "squeeze," characterized by postdive coughing, wheezing, and hemoptysis. Hypoxia and hypercapnia influence the terminal breakpoint beyond which voluntary apnea cannot be sustained. Ascent blackout due to hypoxia is a danger during long breath-holds, and has become common amongst high-level competitors who can suppress their urge to breathe. Decompression sickness due to nitrogen accumulation causing bubble formation can occur after multiple repetitive dives, or after single deep dives during depth record attempts. Humans experience responses similar to those seen in diving mammals, but to a lesser degree. The deepest sled-assisted breath-hold dive was to 214 m. Factors that might determine ultimate human depth capabilities are discussed. © 2018 American Physiological Society. Compr Physiol 8:585-630, 2018. Copyright © 2018 American Physiological Society. All rights reserved.

Controlled breathing protocols probe human autonomic cardiovascular rhythms

NASA Technical Reports Server (NTRS)

Cooke, W. H.; Cox, J. F.; Diedrich, A. M.; Taylor, J. A.; Beightol, L. A.; Ames, J. E. 4th; Hoag, J. B.; Seidel, H.; Eckberg, D. L.

1998-01-01

The purpose of this study was to determine how breathing protocols requiring varying degrees of control affect cardiovascular dynamics. We measured inspiratory volume, end-tidal CO2, R-R interval, and arterial pressure spectral power in 10 volunteers who followed the following 5 breathing protocols: 1) uncontrolled breathing for 5 min; 2) stepwise frequency breathing (at 0.3, 0.25, 0.2, 0.15, 0.1, and 0.05 Hz for 2 min each); 3) stepwise frequency breathing as above, but with prescribed tidal volumes; 4) random-frequency breathing (approximately 0.5-0.05 Hz) for 6 min; and 5) fixed-frequency breathing (0.25 Hz) for 5 min. During stepwise breathing, R-R interval and arterial pressure spectral power increased as breathing frequency decreased. Control of inspired volume reduced R-R interval spectral power during 0.1 Hz breathing (P < 0.05). Stepwise and random-breathing protocols yielded comparable coherence and transfer functions between respiration and R-R intervals and systolic pressure and R-R intervals. Random- and fixed-frequency breathing reduced end-tidal CO2 modestly (P < 0.05). Our data suggest that stringent tidal volume control attenuates low-frequency R-R interval oscillations and that fixed- and random-rate breathing may decrease CO2 chemoreceptor stimulation. We conclude that autonomic rhythms measured during different breathing protocols have much in common but that a stepwise protocol without stringent control of inspired volume may allow for the most efficient assessment of short-term respiratory-mediated autonomic oscillations.

Developing the Molybdenum Isotopic Proxy in Marine Barite

NASA Astrophysics Data System (ADS)

Erhardt, A. M.; Paytan, A.; Aggarwal, J.

2006-12-01

Molybdenum isotope ratios in seawater fluctuate in response to changing redox conditions and can provide clues into the degree of global ocean anoxia. The isotopic ratio of molybdenum has been shown to be sensitive to the relative proportion of oxic, suboxic, and euxinic environments. Deposition in oxic environments is isotopically light (~ -1.6‰ for δ^{97/95}Mo) relative to an average crustal source (0‰). Conversely, euxinic environments have been shown to be consistently heavier (~1.3‰) than the oxic sink through time, with suboxic sediments falling between these two signals. Shifts in the relative proportion of each sink, relative to a constant source, would alter the isotopic ratio of seawater over long time scales. Previously, this seawater value, and hence the degree of global anoxia, could only be inferred through mass balance calculations. We seek to quantify the isotopic signature of seawater though time using a phase that directly records this ratio. Marine barite precipitates inorganically in the water column directly from seawater, potentially providing a direct record of seawater characteristics. Molybdenum is a trace constituent of barite, with the molybdate ion substituting for sulfate at concentrations of about 1 ppm. To accurately determine the molybdenum isotopic ratio at these low concentrations (<15 ng per sample), modifications to existing measurement techniques are required. We will present the variations made to existing separation and mass-spectrometry techniques and the calibration of these new methods. The modifications were undertaken to reduce molybdenum blank to below 1 ng per analysis, to quantitatively remove interfering zirconium and to measure precise and reproducible isotope values. Preliminary data will be presented to illustrate potential applications for this new paleoredox proxy. This technique will allow for the measurement of molybdenum isotopic ratios at low concentrations, expanding the breath of compounds and

Reaction time following yoga bellows-type breathing and breath awareness.

PubMed

Telles, Shirley; Yadav, Arti; Gupta, Ram Kumar; Balkrishna, Acharya

2013-08-01

The reaction time (RT) was assessed in two groups of healthy males, yoga group (M age = 29.0 yr.) and non-yoga or control group (M age = 29.0 yr.), with 35 participants each. The yoga group had an average experience of 6 months, while the control group was yoga-naïve. The yoga group was assessed in two sessions, (i) bhastrika pranayama or bellows breathing and (ii) breath awareness, while the control group had a single control session. The two experimental sessions, one with each type of breathing, and the control session consisted of pre- (5 min.), during (18 min.), and post-session epochs (5 min.). Assessments were made in the pre- and post-session epochs using a Multi-Operational Apparatus for Reaction Time. Following 18 min. of bhastrika pranayama there was a statistically significant reduction in number of anticipatory responses compared to before the practice. This suggests that the immediate effect of bhastrika pranayama is to inhibit unnecessary responding to stimuli.

Aerosol collection of the (Bladewerx Corporation) breathing zone monitor and portable workplace monitor.

PubMed

Moore, Murray E; Kennedy, Trevor J; Dimmerling, Paul J

2007-11-01

The Radiation Protection Group at the Los Alamos National Laboratory has a wind tunnel capable of measuring the aerosol collection efficiencies of air sampling devices. In the fall of 2005, the group received an internal Los Alamos request to perform aerosol collection efficiency tests on two air samplers manufactured by the Bladewerx Corporation (Rio Rancho, NM). This paper presents the results from tests performed in the wind tunnel facility at a test velocity of 0.5 m s. The SabreAlert (Portable Workplace Monitor) and the SabreBZM (Breathing Zone Monitor) are both designed to detect and measure the presence of alpha emitting isotopes in atmospheres. The SabreAlert was operated at two test air flow rates of 6 and 45 liters per minute (LPM), and the SabreBZM was operated at two test air flow rates of 3 and 19 LPM. The aerosol collection efficiencies of both samplers were evaluated with oleic acid (monodisperse) liquid droplet aerosols tagged with sodium fluorescein tracer. These test aerosols varied in size from about 2.3 to 17.2 microns (aerodynamic equivalent diameter). The SabreAlert was roughly 100% efficient in aerosol collection at a flow rate of 6 LPM, and had an aerodynamic cutpoint diameter of 11.3 microns at the 45 LPM flow rate. The SabreBZM had an aerodynamic cutpoint diameter of 6.7 microns at the 3 LPM flow rate, but the SabreBZM aerosol collection efficiency never exceeded 13.6% at the 19 LPM test flow rate condition.

Fast-starting after a breath: air-breathing motions are kinematically similar to escape responses in the catfish Hoplosternum littorale

PubMed Central

Domenici, Paolo; Norin, Tommy; Bushnell, Peter G.; Johansen, Jacob L.; Skov, Peter Vilhelm; Svendsen, Morten B. S.; Steffensen, John F.; Abe, Augusto S.

2015-01-01

ABSTRACT Fast-starts are brief accelerations commonly observed in fish within the context of predator–prey interactions. In typical C-start escape responses, fish react to a threatening stimulus by bending their body into a C-shape during the first muscle contraction (i.e. stage 1) which provides a sudden acceleration away from the stimulus. Recently, similar C-starts have been recorded in fish aiming at a prey. Little is known about C-starts outside the context of predator–prey interactions, though recent work has shown that escape response can also be induced by high temperature. Here, we test the hypothesis that air-breathing fish may use C-starts in the context of gulping air at the surface. Hoplosternum littorale is an air-breathing freshwater catfish found in South America. Field video observations reveal that their air-breathing behaviour consists of air-gulping at the surface, followed by a fast turn which re-directs the fish towards the bottom. Using high-speed video in the laboratory, we compared the kinematics of the turn immediately following air-gulping performed by H. littorale in normoxia with those of mechanically-triggered C-start escape responses and with routine (i.e. spontaneous) turns. Our results show that air-breathing events overlap considerably with escape responses with a large stage 1 angle in terms of turning rates, distance covered and the relationship between these rates. Therefore, these two behaviours can be considered kinematically comparable, suggesting that air-breathing in this species is followed by escape-like C-start motions, presumably to minimise time at the surface and exposure to avian predators. These findings show that C-starts can occur in a variety of contexts in which fish may need to get away from areas of potential danger. PMID:25527644

Sleep-disordered Breathing in Cardiac Rehabilitation: Prevalence, Predictors, and Influence on the Six-Minute Walk Test.

PubMed

Loo, Germaine; Chua, Ai-Ping; Tay, Hung-Yong; Poh, Ruth; Tai, Bee-Choo; Lee, Chi-Hang

2016-06-01

Identification of non-traditional risk factors is an important component of cardiac rehabilitation (CR). However, the prevalence and predictors of sleep-disordered breathing (SDB) and its influence on exercise performance in patients attending CR remain poorly described. Patients enrolled in a national CR centre were eligible for a comprehensive SDB screening program. Screening questionnaires for SDB, overnight sleep study, and the 6-minute walk test (6MWT) were conducted. We recruited 332 patients (mean age 62±10 years, 62.4% male) attending CR for primary (29.2%) or secondary (70.8%) prevention, of which 209 successfully completed the overnight sleep study. Sleep-disordered breathing group patients (n=68, 32.5%) were older and had a higher body mass index (BMI) and neck and waist circumferences than the non-SDB group patients. After adjusting for neck and waist circumference, age (OR=1.06; 95% CI 1.02-1.10; p=0.001) and BMI (OR=1.19; 95% CI 1.10-1.30; p<0.001) remained independent predictors of SDB. A high risk of SDB based on the Berlin Questionnaire (43.4% versus 35.5%, p=0.277) or STOP-BANG questionnaire (63.2% versus 53.2%, p=0.170) and excessive daytime sleepiness (Epworth Sleepiness Scale >10, 23.9% versus 17.7%, p=0.297) were similar between the groups. The 6MWT scores were significantly lower in the SDB than non-SDB group (mean difference -32 m; 95% CI -57-7; p=0.013). The relationship was no longer significant after adjusting for age, sex, and waist circumference. Sleep-disordered breathing is prevalent in CR patients and is independently predicted by ageing and obesity. The association between SDB and poorer exercise performance may be explained by age, sex, and waist circumference. Copyright © 2015 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

The relationship of normal body temperature, end-expired breath temperature, and BAC/BrAC ratio in 98 physically fit human test subjects.

PubMed

Cowan, J Mack; Burris, James M; Hughes, James R; Cunningham, Margaret P

2010-06-01

The relationship between normal body temperature, end-expired breath temperature, and blood alcohol concentration (BAC)/breath alcohol concentration (BrAC) ratio was studied in 98 subjects (84 men, 14 women). Subjects consumed alcohol sufficient to produce a BrAC of at least 0.06 g/210 L 45-75 min after drinking. Breath samples were analyzed using an Intoxilyzer 8000 specially equipped to measure breath temperature. Venous blood samples and body temperatures were then taken. The mean body temperature of the men (36.6 degrees C) was lower than the women (37.0 degrees C); however, their mean breath temperatures were virtually identical (men: 34.5 degrees C; women: 34.6 degrees C). The BAC exceeded the BrAC for every subject. BAC/BrAC ratios were calculated from the BAC and BrAC analytical results. There was no difference in the BAC/BrAC ratios for men (1:2379) and women (1:2385). The correlation between BAC and BrAC was high (r = 0.938, p < 0.0001), whereas the correlations between body temperature and end-expired breath temperature, body temperature and BAC/BrAC ratio, and breath temperature and BAC/BrAC ratio were much lower. Neither normal body temperature nor end-expired breath temperature was strongly associated with BAC/BrAC ratio.

Optoacoustic Determination of Carbon Dioxide Concentration in Exhaled Breath in Various Human Diseases*

NASA Astrophysics Data System (ADS)

Ageev, V. G.; Nikiforova, O. Yu.

2016-11-01

We determined the carbon dioxide concentrations in exhaled breath from healthy donors and patients with various diseases from the absorption spectra of test samples, recorded on a laser optoacoustic gas analyzer based on a CO2 laser. We observed that the carbon dioxide concentrations in exhaled breath from healthy donors is higher than in patients with various diseases.

The role of arterial chemoreceptors in the breath-by-breath augmentation of inspiratory effort in rabbits during airway occlusion or elastic loading.

PubMed

Callanan, D; Read, D J

1974-08-01

1. The breath-by-breath augmentation of inspiratory effort in the five breaths following airway occlusion or elastic loading was assessed in anaesthetized rabbits from changes of airway pressure, diaphragm e.m.g. and lung volume.2. When the airway was occluded in animals breathing air, arterial O(2) tension fell by 20 mmHg and CO(2) tension rose by 7 mmHg within the time of the first five loaded breaths.3. Inhalation of 100% O(2) or carotid denervation markedly reduced the breath-by-breath progression but had little or no effect on the responses at the first loaded breath.4. These results indicate that the breath-by-breath augmentation of inspiratory effort following addition of a load is mainly due to asphyxial stimulation of the carotid bodies, rather than to the gradual emergence of a powerful load-compensating reflex originating in the chest-wall, as postulated by some workers.5. The small residual progression seen in animals breathing 100% O(2) or following carotid denervation was not eliminated (a) by combining these procedures or (b) by addition of gas to the lungs to prevent the progressive lung deflation which occurred during airway occlusion.6. Bilateral vagotomy, when combined with carotid denervation, abolished the residual breath-by-breath progression of inspiratory effort.

Breath Methane Levels Are Increased Among Patients with Diverticulosis.

PubMed

Yazici, Cemal; Arslan, Deniz Cagil; Abraham, Rana; Cushing, Kelly; Keshavarzian, Ali; Mutlu, Ece A

2016-09-01

Diverticulosis and its complications are important healthcare problems in the USA and throughout the Western world. While mechanisms as to how diverticulosis occurs have partially been explored, few studies examined the relationship between colonic gases such as methane and diverticulosis in humans. This study aimed to demonstrate a significant relationship between methanogenic Archaea and development of diverticulosis. Subjects who consecutively underwent hydrogen breath test at Rush University Medical Center between 2003 and 2010 were identified retrospectively through a database. Medical records were reviewed for presence of a colonoscopy report. Two hundred and sixty-four subjects were identified who had both a breath methane level measurement and a colonoscopy result. Additional demographic and clinical data were obtained with chart review. Mean breath methane levels were higher in subjects with diverticulosis compared to those without diverticulosis (7.89 vs. 4.94 ppm, p = 0.04). Methane producers (defined as those with baseline fasting breath methane level >5 ppm) were more frequent among subjects with diverticulosis compared to those without diverticulosis (50.9 vs. 34 %, p = 0.0025). When adjusted for confounders, breath methane levels and age were the two independent predictors of diverticulosis on colonoscopy with logistic regression modeling. Methanogenesis is associated with the presence of diverticulosis. Further studies are needed to confirm our findings and prospectively evaluate a possible etiological role of methanogenesis and methanogenic archaea in diverticulosis.

SeHCAT absorption: a simple test of ileal dysfunction.

PubMed

Fagan, E A; Chadwick, V S; Baird, I M

1983-01-01

A new selenium-labelled synthetic bile salt SeHCAT (taurine conjugate of 23-[75Se]-25-homocholic acid) was assessed as a test of ileal dysfunction in 20 patients with inflammatory bowel disease (IBD). Whole body retention of SeHCAT was compared with tests of vitamin B12 absorption (Schilling test and whole body retention) and the cholylglycine-1-14C breath test and faecal isotope excretion. Clear differentiation, with no overlap was obtained between 10 normal subjects and patients with ileal disease/resection in the SeHCAT 7-day retention results. The Schilling test was more sensitive; enabling discrimination between patients with limited and extensive ileal disease/resection. An unexpected rise in SeHCAT retention was observed in patients with colonic IBD. The 7-day SeHCAT retention is a safe, simple screening test for ileal dysfunction and has practical advantages compared with the Schilling test.

PERIODIC AIR-BREATHING BEHAVIOUR IN A PRIMITIVE FISH REVEALED BY SPECTRAL ANALYSIS

PubMed

Hedrick; Katz; Jones

1994-12-01

The ventilatory patterns of air-breathing fish are commonly described as 'arrhythmic' or 'irregular' because the variable periods of breath-holding are punctuated by seemingly unpredictable air-breathing events (see Shelton et al. 1986). This apparent arrhythmicity contrasts with the perceived periodism or regularity in the gill ventilation patterns of some fish and with lung ventilation in birds and mammals. In this sense, periodism refers to behaviour that occurs with a definite, recurring interval (Bendat and Piersol, 1986). The characterisation of aerial ventilation patterns in fish as 'aperiodic' has been generally accepted on the basis of qualitative examination and it remains to be validated with rigorous testing. The bowfin, Amia calva (L.), is a primitive air-breathing fish that makes intermittent excursions to the air­water interface to gulp air, which is transferred to its well-vascularized gas bladder. Its phylogenetic position as the only extant member of the sister lineage of modern teleosts affords a unique opportunity to examine the evolution of aerial ventilation and provides a model for the examination of ventilatory patterns in primitive fishes. To establish whether Amia calva exhibit a particular pattern of air-breathing, we examined time series records of aerial ventilations from undisturbed fish over long periods (8 h). These records were the same as those used to calculate average ventilation intervals under a variety of experimental conditions (Hedrick and Jones, 1993). Their study also reported the occurrence of two distinct breath types. Type I breaths were characterised by an exhalation followed by an inhalation, whereas type II breaths were characterised by inhalation only. It was also hypothesized that the type I breaths were employed to meet oxygen demands, whereas the type II breaths were used to regulate gas bladder volume. However, they did not investigate the potential presence of a periodic ventilatory pattern. We now report

A comparison of standard inhalers for asthma with and without alcohol as the propellant on the measurement of alcohol in breath.

PubMed

Ignacio-García, José M; Ignacio-García, Juan M; Almenara-Barrios, José; Chocrón-Giraldez, María J; Hita-Iglesias, Carmen

2005-01-01

Because most bronchodilator inhalers contain propellant gases or a small amount of ethanol as a co-solvent, the potential for these products to generate false readings on a evidential breath alcohol instrument was evaluated in 69 volunteers with clinically stable asthma. All subjects underwent a breath test on an infrared breath alcohol analyzer (Alcotest 7110, Dräger, Lübeck, Germany) before the use of the asthma inhaler and 1 and 5 min after inhalation. The effects of antiasthmatic medications delivered by metered dose inhalers (MDIs) with alcohol as a vehicle, alcohol-free MDIs, and dry powder inhalers were assessed in homogeneous groups of four to five patients. All subjects were alcohol-free on the preliminary breath test. One minute after inhalation, negative readings were only observed in 25 (36.2%) of subjects. In 62.3% of patients, apparent alcohol results were considered interferences or unstable readings by the breath-test instrument. One subject showed a final positive breath alcohol level (0.07 mg/L). After the use of dry powder inhalers, valid results without interferences were obtained. However, 89.6% of patients in which bronchodilators were delivered by MDIs (with propellant gases in the aerosol) showed altered partial readings and labeled the final output as "invalid," but tests performed 5 min after the use of inhalers were valid and correct in all cases. MDIs with propellants as a vehicle may cause false positive breath alcohol readings in some patients. These effects are transient and may be prevented by a 5-10-min interval between the use of MDIs and breath alcohol testing.

Preschool Multiple-Breath Washout Testing. An Official American Thoracic Society Technical Statement.

PubMed

Robinson, Paul D; Latzin, Philipp; Ramsey, Kathryn A; Stanojevic, Sanja; Aurora, Paul; Davis, Stephanie D; Gappa, Monika; Hall, Graham L; Horsley, Alex; Jensen, Renee; Lum, Sooky; Milla, Carlos; Nielsen, Kim G; Pittman, Jessica E; Rosenfeld, Margaret; Singer, Florian; Subbarao, Padmaja; Gustafsson, Per M; Ratjen, Felix

2018-03-01

Obstructive airway disease is nonuniformly distributed throughout the bronchial tree, although the extent to which this occurs can vary among conditions. The multiple-breath washout (MBW) test offers important insights into pediatric lung disease, not available through spirometry or resistance measurements. The European Respiratory Society/American Thoracic Society inert gas washout consensus statement led to the emergence of validated commercial equipment for the age group 6 years and above; specific recommendations for preschool children were beyond the scope of the document. Subsequently, the focus has shifted to MBW applications within preschool subjects (aged 2-6 yr), where a "window of opportunity" exists for early diagnosis of obstructive lung disease and intervention. This preschool-specific technical standards document was developed by an international group of experts, with expertise in both custom-built and commercial MBW equipment. A comprehensive review of published evidence was performed. Recommendations were devised across areas that place specific age-related demands on MBW systems. Citing evidence where available in the literature, recommendations are made regarding procedures that should be used to achieve robust MBW results in the preschool age range. The present work also highlights the important unanswered questions that need to be addressed in future work. Consensus recommendations are outlined to direct interested groups of manufacturers, researchers, and clinicians in preschool device design, test performance, and data analysis for the MBW technique.

Determination of breath isoprene and acetone concentration with a needle-type extraction device in gas chromatography-mass spectrometry.

PubMed

Ueta, Ikuo; Mizuguchi, Ayako; Okamoto, Mitsuyoshi; Sakamaki, Hiroyuki; Hosoe, Masahiko; Ishiguro, Motoyuki; Saito, Yoshihiro

2014-03-20

Isoprene in human breath is said to be related to cholesterol metabolism, and the possibility of the correlations with some clinical parameters has been studied. However, at this stage, no clear benefit of breath isoprene has been reported for clinical diagnosis. In this work, isoprene and acetone concentrations were measured in the breath of healthy and obese subjects using a needle-type extraction device for subsequent analysis in gas chromatography-mass spectrometry (GC-MS) to investigate the possibility of these compounds as an indicator of possible diseases. After measuring intraday and interday variations of isoprene and acetone concentrations in breath samples of healthy subjects, their concentrations were also determined in 80 healthy and 17 obese subjects. In addition, correlation between these breath concentrations and the blood tests result was studied for these healthy and obese subjects. The results indicated successful determination of breath isoprene and acetone in this work, however, no clear correlation was observed between these measured values and the blood test results. Breath isoprene concentration may not be a useful indicator for obesity or hypercholesterolemia. Copyright © 2014 Elsevier B.V. All rights reserved.

Comparison of 72-hour fecal fat quantification and the 13C-mixed triglyceride breath test in assessing pancreatic exocrine sufficiency in children with chronic pancreatitis.

PubMed

Wejnarska, Karolina; Kołodziejczyk, Elwira; Ryżko, Józef; Oracz, Grzegorz

Chronic pancreatitis (CP) in children is still a rare, although increasingly recognized entity. Over the duration of the disease several complications can be observed, two of which are major ones: endo- and exocrine insufficiency. In the medical care of children with CP it is crucial to diagnose the decreased endo- and exocrine function of the pancreas, in order to preserve patients from malnutrition and the failure to thrive. The aim of the study was to compare the usefulness of two indirect methods of assessing the pancreas exocrine function in children with CP. Ninety one patients with CP were enrolled in the study (41 boys, 50 girls, aged 2-17.8 years). Only Patients who had had both the 72-hour fecal fat quantification and the 13C-mixed triglyceride breath test (13C -MTBT) performed were selected. We compared the results of both tests for sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) in detecting exocrine pancreatic insufficiency. Out of 91 patients, 12 were diagnosed with exocrine pancreatic insufficiency (EPI). The sensitivity of the fecal fat quantification was 50%, the specificity for the test was 100%. PPV and NPV were 100% and 93%, respectively. 13C-MTBT had the sensitivity of 42% and the specificity of 99%. PPV and NPV for the breath test were of 83% and 92%, respectively. No statistically significant discrepancy between the values obtained was found. Although the 72-hour fecal fat quantification remains the gold standard in detecting EPI, both of the methods that had been investigated were shown to be comparable regarding sensitivity, specificity, PPV and NPV in assessing pancreas exocrine sufficiency in children with CP. Due to the easier execution of the breath test, both for the patient and for medical personnel, its importance may increase.

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.

Analytical methodologies for broad metabolite coverage of exhaled breath condensate.

PubMed

Aksenov, Alexander A; Zamuruyev, Konstantin O; Pasamontes, Alberto; Brown, Joshua F; Schivo, Michael; Foutouhi, Soraya; Weimer, Bart C; Kenyon, Nicholas J; Davis, Cristina E

2017-09-01

Breath analysis has been gaining popularity as a non-invasive technique that is amenable to a broad range of medical uses. One of the persistent problems hampering the wide application of the breath analysis method is measurement variability of metabolite abundances stemming from differences in both sampling and analysis methodologies used in various studies. Mass spectrometry has been a method of choice for comprehensive metabolomic analysis. For the first time in the present study, we juxtapose the most commonly employed mass spectrometry-based analysis methodologies and directly compare the resultant coverages of detected compounds in exhaled breath condensate in order to guide methodology choices for exhaled breath condensate analysis studies. Four methods were explored to broaden the range of measured compounds across both the volatile and non-volatile domain. Liquid phase sampling with polyacrylate Solid-Phase MicroExtraction fiber, liquid phase extraction with a polydimethylsiloxane patch, and headspace sampling using Carboxen/Polydimethylsiloxane Solid-Phase MicroExtraction (SPME) followed by gas chromatography mass spectrometry were tested for the analysis of volatile fraction. Hydrophilic interaction liquid chromatography and reversed-phase chromatography high performance liquid chromatography mass spectrometry were used for analysis of non-volatile fraction. We found that liquid phase breath condensate extraction was notably superior compared to headspace extraction and differences in employed sorbents manifested altered metabolite coverages. The most pronounced effect was substantially enhanced metabolite capture for larger, higher-boiling compounds using polyacrylate SPME liquid phase sampling. The analysis of the non-volatile fraction of breath condensate by hydrophilic and reverse phase high performance liquid chromatography mass spectrometry indicated orthogonal metabolite coverage by these chromatography modes. We found that the metabolite coverage

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…

Air-Breathing Ramjet Electric Propulsion for Controlling Low-Orbit Spacecraft Motion to Compensate for Aerodynamic Drag

NASA Astrophysics Data System (ADS)

Erofeev, A. I.; Nikiforov, A. P.; Popov, G. A.; Suvorov, M. O.; Syrin, S. A.; Khartov, S. A.

2017-12-01

Problems on designing the air-breathing ramjet electric propulsion thruster for controlling loworbit spacecraft motion are examined in the paper. Information for choosing orbits' altitudes for reasonable application of an air-breathing ramjet electric propulsion thruster and propellant exhaust velocity is presented. Estimates of the probable increase of gas concentration in the area of air-breathing ramjet ionization are presented. The test results of the thruster are also given.

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

PubMed

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

2013-12-04

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.

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

Molybdenum isotope fractionation and speciation in a euxinic lake—Testing ways to discern isotope fractionation processes in a sulfidic setting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dahl, Tais W.; Wirth, Stefanie B.

The molybdenum (Mo) isotope composition in euxinic shales has been used as a proxy for the global distribution of anoxic conditions in ancient oceans, and since more recently also as a proxy for sulfide concentrations in depositional environments. However, there is currently no way to distinguish isotope fractionation at low bottom water sulfide concentrations in ‘local’ basins from ‘global’ secular isotope variations associated with changing seawater composition. This uncertainty is challenging the use of Mo isotopes for paleoceanographic reconstructions. To explore this further, we present new data from sediments deposited over the past ~ 9800 years in one of themore » best studied euxinic localities in the world: Lake Cadagno in Switzerland. The sample set allows us to test ways to discern isotope fractionation processes at play in a highly restricted euxinic basin. Most of our drill core samples (n = 18) show high δ98Mo values similar to previously studied shallow sediments, indicative of quantitative Mo removal from the water column (Dahl et al. 2010a). However, a few samples (n = 3) deposited between about 1200 and 3400 years ago carry low δ98Mo values and have been isotopically fractionated in the lake. Sedimentological and geochemical characterizations show that these δ98Mo-fractionated sediments formed during times of frequent injection of O2- and sediment-rich river water into the deep sulfidic water column. A positive correlation between δ98Mo and sedimentary Mo contents suggests that isotope fractionation occurred during times of non-quantitative Mo removal, although Mn-oxide cycling at the chemocline might also contribute a subordinate proportion of (98Mo-depleted) molybdenum into the sulfidic zone. Sedimentary Mo/U enrichments relative to oxic lake water further supports the hypothesis that a particulate Mo shuttle was most efficient during times of quantitative Mo removal. Therefore, periods with inefficient Mo capture are ascribed to

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

Exhaled breath condensate pH decreases following oral glucose tolerance test.

PubMed

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

2015-12-15

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

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.

Performance evaluation : balloon-type breath alcohol self tester for personal use

DOT National Transportation Integrated Search

1984-01-01

The accuracy of the only breath alcohol balloon-type self test device being marketed for personal use (Luckey Laboratories DM-2) was assessed in the laboratory. Data regarding this self-test device's ability to accurately classify an individual as ha...

Silicon Isotopes doping experiments to measure quartz dissolution and precipitation rates at equilibrium and test the principle of detailed balance

NASA Astrophysics Data System (ADS)

Zhu, C.; Rimstidt, J. D.; Liu, Z.; Yuan, H.

2016-12-01

The principle of detailed balance (PDB) has been a cornerstone for irreversible thermodynamics and chemical kinetics for a long time, and its wide application in geochemistry has mostly been implicit and without experimental testing of its applicability. Nevertheless, many extrapolations based on PDB without experimental validation have far reaching impacts on society's mega environmental enterprises. Here we report an isotope doping method that independently measures simultaneous dissolution and precipitation rates and can test this principle. The technique reacts a solution enriched in a rare isotope of an element with a solid having natural isotopic abundances (Beck et al., 1992; Gaillardet, 2008; Gruber et al., 2013). Dissolution and precipitation rates are found from the changing isotopic ratios. Our quartz experiment doped with 29Si showed that the equilibrium dissolution rate remains unchanged at all degrees of undersaturation. We recommend this approach to test the validity of using the detailed balance relationship in rate equations for other substances.

Liver diffusivity in healthy volunteers and patients with chronic liver disease: Comparison of breath-hold and free-breathing techniques

PubMed Central

Eatesam, Mamak; Noworolski, Susan M; Tien, Phyllis C; Nystrom, Michelle; Dodge, Jennifer L.; Merriman, Raphael B.; Qayyum, Aliya

2011-01-01

Purpose To compare liver ADC obtained with breath-hold and free-breathing diffusion weighted imaging (DWI) in healthy volunteers and patients with liver disease. Materials and Methods Twenty-eight subjects, 12 healthy volunteers and 16 patients (9 NAFLD, 7 chronic active HCV), underwent breath-hold (BH) and free-breathing (FB) DWI MRI at 1.5T. Pearson’s correlation coefficient was used to determine correlation while paired t-tests assessed differences between BH and FB ADC. Estimated bias was calculated using the Bland-Altman method. Results Liver ADC (×10−3 mm2/sec) was lower on BH for all groups (mean difference 0.36±0.20; p<0.01). ADC was higher in healthy volunteers (BH 1.80±0.18; FB 2.24±0.20) compared to NAFLD patients (BH 1.43±0.27; FB 1.78±0.28) (p<0.001) and HCV patients (BH 1.63±0.191; FB 1.88±0.12). Overall correlation between BH and FB ADC was (r =0.75), greatest in NAFLD (r =0.90) compared to the correlation in HCV (r =0.24) and healthy subjects (r =0.34). Bland-Altman plots did not show agreement in mean absolute difference and estimated bias between subjects. Conclusion Correlation between BH and FB liver ADC is moderate indicating that BH and FB should not be used interchangeably. Additionally, the lower ADC values in BH versus FB should be accounted for when comparing different liver DWI studies. PMID:22034200

New breathing functions for the transverse breathing crack of the cracked rotor system: Approach for critical and subcritical harmonic analysis

NASA Astrophysics Data System (ADS)

Al-Shudeifat, Mohammad A.; Butcher, Eric A.

2011-01-01

The actual breathing mechanism of the transverse breathing crack in the cracked rotor system that appears due to the shaft weight is addressed here. As a result, the correct time-varying area moments of inertia for the cracked element cross-section during shaft rotation are also determined. Hence, two new breathing functions are identified to represent the actual breathing effect on the cracked element stiffness matrix. The new breathing functions are used in formulating the time-varying finite element stiffness matrix of the cracked element. The finite element equations of motion are then formulated for the cracked rotor system and solved via harmonic balance method for response, whirl orbits and the shift in the critical and subcritical speeds. The analytical results of this approach are compared with some previously published results obtained using approximate formulas for the breathing mechanism. The comparison shows that the previously used breathing function is a weak model for the breathing mechanism in the cracked rotor even for small crack depths. The new breathing functions give more accurate results for the dynamic behavior of the cracked rotor system for a wide range of the crack depths. The current approach is found to be efficient for crack detection since the critical and subcritical shaft speeds, the unique vibration signature in the neighborhood of the subcritical speeds and the sensitivity to the unbalance force direction all together can be utilized to detect the breathing crack before further damage occurs.

The accuracy of coin-operated breath analysers installed in licensed premises in the Perth metropolitan area.

PubMed

Hay, Greg; Cercarelli, L Rina

2004-04-01

To examine the accuracy of coin-operated breath analysers installed in licensed premises in the Perth metropolitan area. Two hundred licensed premises were contacted, which resulted in the location of 36 wall-mounted, coin-operated breath analysers. One instrument was removed prior to testing. These premises were then visited and the accuracy of the instruments was tested in situ using National Association of Testing Authorities Australia (NATA) certified 0.080% and 0.100% ethanol in nitrogen gas. The instruments were installed in the licensed premises as follows: 15 in the lounge bar, 10 in the main entrance, six in the public bar, two in the passageway to the toilets, and one in the male toilets. One licensed premise provided a handheld breath instrument. All instruments were accompanied by warning and operating instructions, but only five had any educational material. Only seven of the licensed premises had staff who had received any training in the operation of the wall-mounted instruments. Half of the licensees were unaware of the servicing requirements of the instruments. The testing found that only nine (25%) of the instruments provided acceptable results. The low level of accuracy of coin-operated breath analysers in the Perth metropolitan area is alarming and users should be informed of the potential inaccuracies. This paper, however, does not rule out that some wall-mounted breath analysing instruments may provide accurate results when properly maintained.

Breathing exercises with vagal biofeedback may benefit patients with functional dyspepsia.

PubMed

Hjelland, Ina E; Svebak, Sven; Berstad, Arnold; Flatabø, Geir; Hausken, Trygve

2007-09-01

Many patients with functional dyspepsia (FD) have postprandial symptoms, impaired gastric accommodation and low vagal tone. The aim of this study was to improve vagal tone, and thereby also drinking capacity, intragastric volume and quality of life, using breathing exercises with vagal biofeedback. Forty FD patients were randomized to either a biofeedback group or a control group. The patients received similar information and care. Patients in the biofeedback group were trained in breathing exercises, 6 breaths/min, 5 min each day for 4 weeks, using specially designed software for vagal biofeedback. Effect variables included maximal drinking capacity using a drink test (Toro clear meat soup 100 ml/min), intragastric volume at maximal drinking capacity, respiratory sinus arrhythmia (RSA), skin conductance (SC) and dyspepsia-related quality of life scores. Drinking capacity and quality of life improved significantly more in the biofeedback group than in the control group (p=0.02 and p=0.01) without any significant change in baseline autonomic activity (RSA and SC) or intragastric volume. After the treatment period, RSA during breathing exercises was significantly correlated to drinking capacity (r=0.6, p=0.008). Breathing exercises with vagal biofeedback increased drinking capacity and improved quality of life in FD patients, but did not improve baseline vagal tone.

Unloading work of breathing during high-frequency oscillatory ventilation: a bench study

PubMed Central

van Heerde, Marc; Roubik, Karel; Kopelent, Vitek; Plötz, Frans B; Markhorst, Dick G

2006-01-01

Introduction With the 3100B high-frequency oscillatory ventilator (SensorMedics, Yorba Linda, CA, USA), patients' spontaneous breathing efforts result in a high level of imposed work of breathing (WOB). Therefore, spontaneous breathing often has to be suppressed during high-frequency oscillatory ventilation (HFOV). A demand-flow system was designed to reduce imposed WOB. Methods An external gas flow controller (demand-flow system) accommodates the ventilator fresh gas flow during spontaneous breathing simulation. A control algorithm detects breathing effort and regulates the demand-flow valve. The effectiveness of this system has been evaluated in a bench test. The Campbell diagram and pressure time product (PTP) are used to quantify the imposed workload. Results Using the demand-flow system, imposed WOB is considerably reduced. The demand-flow system reduces inspiratory imposed WOB by 30% to 56% and inspiratory imposed PTP by 38% to 59% compared to continuous fresh gas flow. Expiratory imposed WOB was decreased as well by 12% to 49%. In simulations of shallow to normal breathing for an adult, imposed WOB is 0.5 J l-1 at maximum. Fluctuations in mean airway pressure on account of spontaneous breathing are markedly reduced. Conclusion The use of the demand-flow system during HFOV results in a reduction of both imposed WOB and fluctuation in mean airway pressure. The level of imposed WOB was reduced to the physiological range of WOB. Potentially, this makes maintenance of spontaneous breathing during HFOV possible and easier in a clinical setting. Early initiation of HFOV seems more possible with this system and the possibility of weaning of patients directly on a high-frequency oscillatory ventilator is not excluded either. PMID:16848915

Cardiorespiratory interactions during resistive load breathing.

PubMed

Calabrese, P; Perrault, H; Dinh, T P; Eberhard, A; Benchetrit, G

2000-12-01

The addition to the respiratory system of a resistive load results in breathing pattern changes and in negative intrathoracic pressure increases. The aim of this study was to use resistive load breathing as a stimulus to the cardiorespiratory interaction and to examine the extent of the changes in heart rate variability (HRV) and respiratory sinus arrhythmia (RSA) in relation to the breathing pattern changes. HRV and RSA were studied in seven healthy subjects where four resistive loads were applied in a random order during the breath and 8-min recording made in each condition. The HRV spectral power components were computed from the R-R interval sequences, and the RSA amplitude and phase were computed from the sinusoid fitting the instantaneous heart rate within each breath. Adding resistive loads resulted in 1) increasing respiratory period, 2) unchanging heart rate, and 3) increasing HRV and changing RSA characteristics. HRV and RSA characteristics are linearly correlated to the respiratory period. These modifications appear to be linked to load-induced changes in the respiratory period in each individual, because HRV and RSA characteristics are similar at a respiratory period obtained either by loading or by imposed frequency breathing. The present results are discussed with regard to the importance of the breathing cycle duration in these cardiorespiratory interactions, suggesting that these interactions may depend on the time necessary for activation and dissipation of neurotransmitters involved in RSA.

No radiation protection reasons for restrictions on 14C urea breath tests in children.

PubMed

Gunnarsson, M; Leide-Svegborn, S; Stenström, K; Skog, G; Nilsson, L-E; Hellborg, R; Mattsson, S

2002-12-01

Traditional (14)C urea breath tests are normally not used for younger children because the radiation exposure is unknown. High sensitivity accelerator mass spectrometry and an ultra-low amount (440 Bq) of (14)C urea were therefore used both to diagnose Helicobacter pylori (HP) infection in seven children, aged 3-6 years, and to make radiation dose estimates. The activity used was 125 times lower than the amount normally used for older children and 250 times lower than that used for adults. Results were compared with previously reported biokinetic and dosimetric data for adults and older children aged 7-14 years. (14)C activity concentrations in urine and exhaled air per unit administered activity for younger children (3-6 years) correspond well with those for older children (7-14 years). For a child aged 3-6 years who is HP negative, the urinary bladder wall receives the highest absorbed dose, 0.3 mGy MBq(-1). The effective dose is 0.1 mSv MBq(-1) for the 3-year-old child and 0.07 mSv MBq(-1) for the 6-year-old child. For two children, the 10 min and 20 min post-(14)C administration samples of exhaled air showed a significantly higher amount of (14)C activity than for the rest of the children, that is 6% and 19% of administered activity exhaled per hour compared with 0.3-0.9% (mean 0.5%) of administered activity exhaled per hour indicating that these two children that is were HP positive. For a 3-year-old HP positive child, absorbed dose to the urinary bladder wall was 0.3 mGy MBq(-1) and effective dose per unit of administered activity was 0.4 mSv MBq(-1). Using 55 kBq, which is a normal amount for older children when liquid scintillation counters are used for measurement, the effective dose will be approximately 6 micro Sv to a 3-year-old HP negative child and 20 microSv to a HP positive child. Thus there is no reason for restrictions on performing a normal (14)C urea breath test, even on young children.

Breath acidification in adolescent runners exposed to atmospheric pollution: A prospective, repeated measures observational study

PubMed Central

Ferdinands, Jill M; Crawford, Carol A Gotway; Greenwald, Roby; Van Sickle, David; Hunter, Eric; Teague, W Gerald

2008-01-01

Background Vigorous outdoors exercise during an episode of air pollution might cause airway inflammation. The purpose of this study was to examine the effects of vigorous outdoor exercise during peak smog season on breath pH, a biomarker of airway inflammation, in adolescent athletes. Methods We measured breath pH both pre- and post-exercise on ten days during peak smog season in 16 high school athletes engaged in daily long-distance running in a downwind suburb of Atlanta. The association of post-exercise breath pH with ambient ozone and particulate matter concentrations was tested with linear regression. Results We collected 144 pre-exercise and 146 post-exercise breath samples from 16 runners (mean age 14.9 years, 56% male). Median pre-exercise breath pH was 7.58 (interquartile range: 6.90 to 7.86) and did not change significantly after exercise. We observed no significant association between ambient ozone or particulate matter and post-exercise breath pH. However both pre- and post-exercise breath pH were strikingly low in these athletes when compared to a control sample of 14 relatively sedentary healthy adults and to published values of breath pH in healthy subjects. Conclusion Although we did not observe an acute effect of air pollution exposure during exercise on breath pH, breath pH was surprisingly low in this sample of otherwise healthy long-distance runners. We speculate that repetitive vigorous exercise may induce airway acidification. PMID:18328105

Evaluation of a portable evidential breath alcohol analyzer.

PubMed

Razatos, Gerasimos; Luthi, Ruth; Kerrigan, Sarah

2005-10-04

The Scientific Laboratory Division (SLD) of the Department of Health acts by mandate as the regulatory agency for the Implied Consent Program for the State of New Mexico. The Laboratory is responsible for all blood and breath alcohol testing activities for law enforcement statewide. The geographical size and the nature of the state, characterized by a highly rural population, demands portable breath alcohol testing equipment. Moreover, future expansion and success of the breath-testing program has focused on instrument portability and data management as critical issues amongst law enforcement agencies and the courts. Thus, the Implied Consent Section of the SLD evaluated the performance of the Intoxilyzer 8000, a portable instrument, against the Intoxilyzer 5000, a stationary instrument, which is currently approved for use. Instrument performance was evaluated at various ethanol concentrations, ranging from 0.04 to 0.55 g/100mL in blood or g/210 L breath. Special attention was placed on instrument performance at the per se and aggravated DWI levels of 0.08 g/100mL and 0.16 g/dL, respectively, due to their legal significance. Precision and accuracy were evaluated using in-house ethanol controls in a wet bath simulator. Coefficients of variation using the Intoxilyzer 8000 ranged from 0.30 to 1.3% (n=102), while CVs for the Intoxilyzer 5000 were 0.7-2.1% (n=102). Calibration stability was assessed in addition to the distribution of data at concentrations between 0.04 and 0.55 g/210 L. Accuracy was 100-102% for the Intoxilyzer 5000 and 99-101% using the Intoxilyzer 8000. Linear regression analysis of more than 700 comparative measurements revealed an R(2) of 1.000 (y=1.005x-0.001), where the Intoxilyzer 5000 and the Intoxilyzer 8000 were plotted on the x- and y-axis respectively. Instrument response to mouth alcohol and volatile interferences was also investigated. Potential interferences were evaluated alone or in combination with ethanol using a wet bath simulator at

A dual mode breath sampler for the collection of the end-tidal and dead space fractions.

PubMed

Salvo, P; Ferrari, C; Persia, R; Ghimenti, S; Lomonaco, T; Bellagambi, F; Di Francesco, F

2015-06-01

This work presents a breath sampler prototype automatically collecting end-tidal (single and multiple breaths) or dead space air fractions (multiple breaths). This result is achieved by real time measurements of the CO2 partial pressure and airflow during the expiratory and inspiratory phases. Suitable algorithms, used to control a solenoid valve, guarantee that a Nalophan(®) bag is filled with the selected breath fraction even if the subject under test hyperventilates. The breath sampler has low pressure drop (<0.5 kPa) and uses inert or disposable components to avoid bacteriological risk for the patients and contamination of the breath samples. A fully customisable software interface allows a real time control of the hardware and software status. The performances of the breath sampler were evaluated by comparing (a) the CO2 partial pressure calculated during the sampling with the CO2 pressure measured off-line within the Nalophan(®) bag; (b) the concentrations of four selected volatile organic compounds in dead space, end-tidal and mixed breath fractions. Results showed negligible deviations between calculated and off-line CO2 pressure values and the distributions of the selected compounds into dead space, end-tidal and mixed breath fractions were in agreement with their chemical-physical properties. Copyright © 2015. Published by Elsevier Ltd.

Influence of breathing resistance of heat and moisture exchangers on tracheal climate and breathing pattern in laryngectomized individuals.

PubMed

Scheenstra, Renske J; Muller, Sara H; Vincent, Andrew; Sinaasappel, Michiel; Hilgers, Frans J M

2010-08-01

The aim of this study was to determine the influence of breathing resistance of heat and moisture exchangers (HMEs) on endotracheal climate and breathing pattern. Endotracheal temperature and humidity and tidal volumes were measured in 11 laryngectomized patients with a regularly used HME with "standard" breathing resistance (Provox Normal HME; R-HME), a low breathing-resistance HME (Provox HiFlow HME; L-HME), and without HME. Both R-HME and L-HME increased end-inspiratory humidity (+5.8 and 4.7 mgH(2)O/L, respectively), decreased end-inspiratory temperature (-1.6 and -1.0 degrees C, respectively), and prolonged the exhalation breath length to approximately 0.5 seconds. The R-HME significantly enlarged tidal volumes (0.07 L; p < .05). Both HMEs significantly improve tracheal climate. The R-HME has better moistening properties and a small but significant positive effect on tidal volume. Therefore, if the higher resistance is tolerated, the R-HME is the preferred pulmonary rehabilitation device. The L-HME is indicated if lower breathing resistance is required. 2009 Wiley Periodicals, Inc. Head Neck, 2010.

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

... 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: (1... the manufacturer's directions. (11) You must note the fact that you used a breath tube device in Step...

Isotope heat source simulator for testing of space power systems

NASA Technical Reports Server (NTRS)

Prok, G. M.; Smith, R. B.

1973-01-01

A reliable isotope heat source simulator was designed for use in a Brayton power system. This simulator is composed of an electrically heated tungsten wire which is wound around a boron nitride core and enclosed in a graphite jacket. Simulator testing was performed at the expected operating temperature of the Brayton power system. Endurance testing for 5012 hours was followed by cycling the simulator temperature. The integrity of this simulator was maintained throughout testing. Alumina beads served as a diffusion barrier to prevent interaction between the tungsten heater and boron nitride core. The simulator was designed to maintain a surface temperature of 1311 to 1366 K (1900 to 2000 F) with a power input of approximately 400 watts. The design concept and the materials used in the simulator make possible man different geometries. This flexibility increases its potential use.

A Gaussian method to improve work-of-breathing calculations.

PubMed

Petrini, M F; Evans, J N; Wall, M A; Norman, J R

1995-01-01

The work of breathing is a calculated index of pulmonary function in ventilated patients that may be useful in deciding when to wean and when to extubate. However, the accuracy of the calculated work of breathing of the patient (WOBp) can suffer from artifacts introduced by coughing, swallowing, and other non-breathing maneuvers. The WOBp in this case will include not only the usual work of inspiration, but also the work of performing these non-breathing maneuvers. The authors developed a method to objectively eliminate the calculated work of these movements from the work of breathing, based on fitting to a Gaussian curve the variable P, which is obtained from the difference between the esophageal pressure change and the airway pressure change during each breath. In spontaneously breathing adults the normal breaths fit the Gaussian curve, while breaths that contain non-breathing maneuvers do not. In this Gaussian breath-elimination method (GM), breaths that are two standard deviations from that mean obtained by the fit are eliminated. For normally breathing control adult subjects, GM had little effect on WOBp, reducing it from 0.49 to 0.47 J/L (n = 8), while there was a 40% reduction in the coefficient of variation. Non-breathing maneuvers were simulated by coughing, which increased WOBp to 0.88 (n = 6); with the GM correction, WOBp was 0.50 J/L, a value not significantly different from that of normal breathing. Occlusion also increased WOBp to 0.60 J/L, but GM-corrected WOBp was 0.51 J/L, a normal value. As predicted, doubling the respiratory rate did not change the WOBp before or after the GM correction.(ABSTRACT TRUNCATED AT 250 WORDS)

The accuracy of evidential breath testers at low BACs

DOT National Transportation Integrated Search

1989-05-01

This Technical Note reports on the low blood alcohol concentration (BAC) laboratory testing of seven evidential breath testers widely used by law enforcement. The findings indicated that these devices are just as accurate at low BACs in the 0.020-0.0...

Sports-related lung injury during breath-hold diving.

PubMed

Mijacika, Tanja; Dujic, Zeljko

2016-12-01

The number of people practising recreational breath-hold diving is constantly growing, thereby increasing the need for knowledge of the acute and chronic effects such a sport could have on the health of participants. Breath-hold diving is potentially dangerous, mainly because of associated extreme environmental factors such as increased hydrostatic pressure, hypoxia, hypercapnia, hypothermia and strenuous exercise.In this article we focus on the effects of breath-hold diving on pulmonary function. Respiratory symptoms have been reported in almost 25% of breath-hold divers after repetitive diving sessions. Acutely, repetitive breath-hold diving may result in increased transpulmonary capillary pressure, leading to noncardiogenic oedema and/or alveolar haemorrhage. Furthermore, during a breath-hold dive, the chest and lungs are compressed by the increasing pressure of water. Rapid changes in lung air volume during descent or ascent can result in a lung injury known as pulmonary barotrauma. Factors that may influence individual susceptibility to breath-hold diving-induced lung injury range from underlying pulmonary or cardiac dysfunction to genetic predisposition.According to the available data, breath-holding does not result in chronic lung injury. However, studies of large populations of breath-hold divers are necessary to firmly exclude long-term lung damage. Copyright ©ERS 2016.