China
Africa
Explore chapters and articles related to this topic
Tests on Naturally Voided Body Fluids
Published in Robert B. Northrop, Non-Invasive Instrumentation and Measurement in Medical Diagnosis, 2017
There are several tests for H. pylori (MedlinePlus 2013, Patient 2014). The presence of H. pylori in the stomach can definitively be determined invasively by taking a biopsy from a stomach ulcer with a gastroscope. A blood Ab test also is fairly accurate in identifying an H. pylori infection. The accurate, NI, “urea breath test” for the bacterium makes use of the fact that H. pylori survives on the stomach lining by secreting the enzyme, urease. Urease breaks down urea in the stomach contents to ammonia and carbon dioxide. The ammonia forms ammonium hydroxide which neutralizes stomach hydrochloric acid in the vicinity of the bacteria protecting them. The reaction is:2H2N(13CO)NH2+2H2O→urease4 NH3+213CO2↑.
Raman gas spectroscopy
Published in P. Dakin John, G. W. Brown Robert, Handbook of Optoelectronics, 2017
Andreas Knebl, Jürgen Popp, Torsten Frosch
Molecular hydrogen and methane are biomarkers in the human breath for malabsorption disorders. Hanf et al.8 showed that FERS is suited well as highly sensitive and selective point-of-care examination method. They demonstrated the ability to monitor the levels of H2 and CH4 indicative for oligosaccharide intolerances or small intestinal bacterial overgrowth syndrome (SIBO); see Figure 19.6. In a hydrogen breath test—a diagnostic tool for different malabsorption disorders—an increase of 20 ppm above basal is considered positive. An elevation above 12 ppm is already an indicator for SIBO. As H2 can be converted to CH4 by bowel bacteria, the latter also is an important parameter that should be checked in addition8 to increase the diagnostic sensitivity.
Solid-State Gas Sensors for Clinical Diagnosis
Published in Krzysztof Iniewski, Biological and Medical Sensor Technologies, 2017
Hydrogen breath test represent a valid and noninvasive diagnostic tool in many gastroenterological conditions [64]. The test is based on the concept that part of the gas produced by colonic bacterial fermentation diffuses into the blood and is found in the breath, where it can be quantified easily. Indeed, in fasting subjects, H2 production is normally low, but, after ingestion of fermentable substrates, primarily carbohydrates, anaerobic bacteria release appreciable amounts of H2.
First evaluation of the possibility of testing for drugged driving using exhaled breath sampling
Published in Traffic Injury Prevention, 2019
Olof Beck, Shahid Ullah, Robert Kronstrand
In addition to breath tests for alcohol, some countries have implemented roadside drug testing using an oral fluid specimen, but most countries rely on signs and symptoms of impairment as a tool to require a sample for confirmation of drugs of abuse (Davey et al. 2017).