Showing papers on "Breath test published in 1980"

Expired air carbon monoxide: a simple breath test of tobacco smoke intake.

Abstract: the buzzer alarm, and the figure for hospital B was 33 °'%. By far the commonest difficulty was failure to awake to the alarm. Most of these patients stopped using the buzzer altogether because of the difficulties, most of which occurred in the first week of using the buzzer alarm. The percentage of patients who could be said to have been cured of their nocturnal enuresis was only 17 % at hospital A and 41 % at hospital B. The figure compares the effectiveness of the buzzer in this study with Meadows's results.'

Predicting outcome of paracetamol poisoning by use 14C-aminopyrine breath test.

Abstract: The 14C-aminopyrine (14C-amidopyrine) breath test, carried out within 24-36 hours of an overdosage of paracetamol, was used to predict the extent of liver damage in 30 seriously poisoned patients. Mean 14CO2 excretion was 4.4% in 20 healthy control subjects; 5.5% in six patients who escaped injury; and 2.9%, 1.5%, and 0.2% in those with mild to moderate (12 patients), severe (eight patients), and fatal (four patients) liver damage respectively. This test proved to be a more reliable predictor of the extent of liver damage than plasma paracetamol concentration or half life or the results of conventional liver function tests and may enable treatment of hepatic failure to be started at an early stage.

Comparison of the one-gram d-[14C]xylose breath test to the [14C]bile acid breath test in patients with small-intestine bacterial overgrowth.

Abstract: In twelve patients with culture-proven bacterial overgrowth of the small intestine, the ability of a newly-developed one-gramd-[14C]xylose breath test to detect bacterial overgrowth was compared to that of the [14C]bile acid breath test. All patients manifested excessive production of breath14CO2 after the administration of one gram [14C]xylose, with 83% of the patients being abnormal within the first hour of testing. In contrast, during the [14C]bile acid breath test, four of the twelve patients had no period of excessive14CO2 production (above the 95% confidence range of controls). Nutrient malabsorption (fat, cobalamin, xylose) was seen with both true-positive and false-negative bile acid breath tests. The one gram [14C]xylose breath test, utilizing a substrate with more predominant absorption in the proximal small intestine and which can be catabolized by Gram-negative aerobic bacteria, appears to have a greater degree of sensitivity and specificity than the bile acid breath test in detecting the presence of small-intestine bacterial overgrowth.

The measurement of breath alcohol. The laboratory evaluation of substantive breath test equipment and the report of an operational police trial

Abstract: Immediately following the publication of the Blennerhassett report on Drinking and Driving, the Home Office set up a group of scientists at the Central Research Establishment to evaluate breath alcohol testing instruments currently available throughout the world. The instruments which passed the laboratory testing were then evaluated under field conditions. Between 1 December 1977 and 26 June 1978 twelve substantive breath alcohol testing instruments, (four Intoxilyzers, four Mk. IV G.C. Intoximeters and four Breathalyzers), were used by police officers at twelve police stations, geographically widely spaced throughout Great Britain. All three types of instrument were used, in turn, at each location to test motorists who had provided specimens for laboratory analysis under the provisions of the Road Traffic Act (RTA), 1972. 1776 motorists were invited to assist during the period of the trial. Of the 1516 (85%) who agreed to provide specimens of breath, 1336 provided specimens of blood for analysis, and 991 of these cases were considered suitable for scientific comparisons between the breath instrument results and the blood alcohol concentration (BAC) reported on the Certificate of Analysis from the Forensic Science Laboratory, issued under the Road Traffic Act (RTA), 1972. These comparisons are described in detail and are used to indicate the practicability of breath analysis being used to replace blood or urine analysis for alcohol. The performance and durability of the equipment is described.

Tests of Bile-acid and Vitamin B12 Metabolism in Ileal Crohn’s Disease

Abstract: The bile-acid breath test, fecal analysis of labeled bile acids, and Schilling test were used to study bile-acid and vitamin B12 metabolism in 31 patients with ileal Crohn's disease. Results of the bile-acid breath test were positive for 42% of the patients; Schilling test, 42%; fecal analysis of bile-acid labels, 19%. Combination of the tests increased the percentage of positive cases to 65. About 50% of the patients who had positive breath tests had evidence of normal bile-acid absorption, indicating increased bile-acid deconjugation by small-intestinal bacteria. The other 50% had evidence of various degrees of bile-acid malabsorption. Disease activity did not correlate with results of any test. Extent of ileal involvement correlated with results of the bile-acid tests, but not with those of the Schilling test. The study demonstrates that there is a wide spectrum of disturbances of bile-acid and vitamin B12 metabolism in ileitis, and that the tests should be useful in the diagnostic evaluation of patients with proven or questionable Crohn's disease who have diarrhea and malabsorptive abnormalities that could be related to disturbances of bile-acid and vitamin B12 metabolism.

Small intestinal bacterial growth in systemic sclerosis

Abstract: Summary Twenty unselected patients with proven systemic sclerosis had cultures of jejunal juice, and glucose/hydrogen breath tests for small intestinal bacterial overgrowth. Seven had counts of over I06 organisms/ml, higher than was ever found in a control group. Four of these seven had a positive breath test. Small intestinal bacterial overgrowth appears to be relatively common in systemic sclerosis, affecting approximately one-third of unselected patients.

Measurement of pulmonary hydrogen (H2) and H2 diffusion from the small bowel and the colon.

Abstract: An accurate, relatively simple gas-solid chromatographic method for determination of breath H2 is described. Three different end-expiratory breath sampling techniques were evaluated. Changes in ventilatory activity was found to be the main cause of inaccuracies in end-expiratory breath H2 determinations. Pulmonary H2 excretion was measured after instillations of H2 in jejunum and colon. H2 excretion during the first 30 min after instillation was approximately seven times greater from the jejunum than from the colon. Marked individual variability was noted, and it is suggested that this may be explained by variations in intestinal peristaltic activity, which must be of importance in the process of H2 diffusion from gut lumen. It is further suggested that the H2 breath test should be regarded as a semi-quantitative test for intestinal H2 formation.

Bacterial overgrowth in ileal reservoirs (Koch pouch): extended functional studies.

Abstract: An absorptive, hormonal, bacteriological and morphological study was performed in 9 proctocolectomized patients with continent ileal reservoirs established for 2-57 months. Vitamin B 12 malassimilation (as assessed by the Schilling test and serum vitamin B 12 concentration), bile salt deconjugation (modified 14C-glycocholate breath test), increased stool fat excretion and high intestinal sodium loss with secondary hyperreninism/hyperaldosteronism were encountered in a large percentage of patients; proximal small intestinal absorption (serum parameters, xylose test) appeared intact. In reservoir stool samples total and differential bacterial cell counts yielded values close to a normal rectum flora. Morphologically (endoscopy, quantitative histology) the reservoir mucosa showed moderate to severe inflammation; structural changes were essentially absent and inflammation in the adjoining ileum was minimal. These results indicate that reservoir bacteria frequently produce disturbances in small intestinal function and that these may be found without secondary structural transformation of the mucosa.

An evaluation of the 14C-glycocholic acid breath test in the diagnosis of bacterial colonisation of the jejunum.

Abstract: In order to assess the performance of the 14C-glycocholic acid breath test as an indicator of bacterial colonisation of the jejunum, 145 combined breath tests and jejunal aspirate cultures were carried out on a total of 50 subjects who had an increased probability of being colonised Ninety-one of the 145 cultures were positive while only 31 of the breath tests were positive This poor performance of the breath test relative to the aspirate culture can be predicted with reasonable accuracy from known bile deconjugating capabilities of bacteria found in the small intestine

[The galactose breath test. Modification of the method and comparison with galactose elimination capacity and plasma disappearance of bromsulphatein (author's transl)].

Abstract: The paper describes a modification of the galactose breath test (GBT) for assessing liver function. Following iv injection of 0.5 g galactose per kg body weight, together with 2 mu Ci generally 14C-labelled galactose, 14CO2 is collected in regular intervals during one hour. Since 14C-activity in breath exhibits a linear rise during 70--100 minutes, the curve obtained permits calculation of an initial slope, as well as the "standardized specific activity" after 45 min GBT was performed in 8 liver normals, 8 alcoholic cirrhotics, 4 patients with chronic active hepatitis (CAH) and 6 with primary biliary cirrhosis (PBC). The results were compared with the simultaneously measured galactose elimination capacity (GEC) and the initial plasma disappearance (ki) of bromsulphthalein (BSP). In the liver normals, the values for initial slope and standardized specific activity were 1.08 +/- S.D. 0.3 and 0.42 +/- S.D. 0.1, respectively. In comparison, the values obtained in all patients groups were markedly reduced. CAH patients exhibited the most severe decrease; the reduction was smallest in PBC patients. The GBT discriminated well between liver normals and patients with liver disease (p less than 0.001, t-test). The results of the GBT correlated linearly with GEC (r = 0.86 and 0.87, respectively) and with BSP-ki (r = 0.9 and 0.92, respectively). These results suggest that the GBT may be regarded as a quantitative measure of a cystosolic hepatic function.

Limited usefulness of the breath test in evaluation of drug metabolism: a study in human oral contraceptive users treated with dimethylaminoantipyrine and diazepam.

Abstract: 30 healthy female volunteers were tested in 5 groups of 6 persons each to evaluate whether oral contraceptives (OCs) had inhibiting effects on the disposal via the hepatic microsomal enzyme system of radiolabeled diazepam. Therefore demethylation of radiolabeled aminopyrine and diazepam was measured by a breath test in women using OCs and in controls. Short-term half-life of radiolabeled carbon dioxide in the breath after ingestion of 2 mcCi of aminopyrine was significantly prolonged in women using OCs compared with controls. After ingestion of 2 mcCi of diazepan there was no statistically significant difference between the 2 groups. With 2 mcC; of diazepam or 10 mcCi of aminopyrine a biexponential decline of radiolabeled carbon dioxide content in the breath was superimposed on a circadian rhythm and the carbon dioxide in the aminopyrine breath test increased after patients had risen from bed whereas it decreased in the diazepam test. It is concluded that the effect of OCs on drug metabolism is very specific and that furthermore the appearance of radiolabeled carbon dioxide in the breath does not depend only on hepatic microsomal demethylation.

The development of n-demethylase activity measured with 13 c-aminopyrine breath test

Abstract: Measurement of specifically labelled CO2 in exspired breath after aminopyrine (AP) demethylation by the hepatic mixed function oxidase system has been shown to be a reliable method for estimation of hepatocellular function. We used the 13C-AP breath test to measure the normal development of the N-demethylase activity and started 13C-methacetin breath test for investigation of O-dealkylation in children. 25 children with normal liver function, aged 2 days to 14 years, received 5 mg/kg body weight AP orally. 13CO2 analysis in breath was performed with a mass spectrometer Varian MAT 230. Results were calculated as cumulative %-recovery of the administered dose. 13C after 2 hours (%-dose), corrected for body weight and endogenous CO2 production. In neonates no 13C excretion could be detected. N-demethylase activity then slowly increased and reached adult levels by 2 years of life.(%-dose = 12.2 ± 2.1). Children with liver disease (%-dose = 4.0 ± 1.3) and treated with antiepileptic drugs (%-dose=16.7 ± 2.5) could be well discriminated. Neonates whose epileptic mother were treated with primidone during pregnancy showed a 13C excretion similar or better than normal adults, thus demonstrating pre- or perinatal inducibility of the N-demethylase activity.