Showing papers on "Breath test published in 1985"

Interpretation of the breath hydrogen profile obtained after ingesting a solid meal containing unabsorbable carbohydrate.

Abstract: The extent to which monitoring breath hydrogen excretion provides information concerning the entry of the residues of a solid test meal into the colon was investigated in 89 normal subjects, and 11 patients with the irritable bowel syndrome. The profile of breath hydrogen concentration showed an early peak, that occurred soon after ingesting the test meal in 89% subjects. This was followed by a later more prolonged rise in breath hydrogen concentration. The early peak occurred well before a radioactive marker, incorporated in the test meal, reached the caecum and the data suggest it was predominantly caused by the emptying of the remnants of the previous meal from the ileum into the colon. This hypothesis was supported by direct measurements of the rate of delivery of ileostomy effluent in 12 subjects with terminal ileostomies. Fermentation of carbohydrate in the mouth may, however, contribute to the initial peak, but this contribution may be avoided by collecting gas samples from the nares. The secondary rise in breath hydrogen excretion was closely correlated with the arrival of the radioactive marker in the caecum (r = 0.91), p less than 0.001), though the time, at which the secondary peak of breath hydrogen excretion occurred was poorly correlated with the time that all the radioactive test meal had entered the colon. When lactulose was infused directly into the colon, as little as 0.5 g produced a discernible hydrogen response, which occurred within two minutes of the infusion. Increasing the rate of colonic infusion of a 50 ml solution of 10% lactulose from 0.02 to 0.15 g/min in five subjects significantly increased the breath hydrogen concentration. At infusion rates below 0.075 g lactulose/minute, the peak breath hydrogen response preceded the end ot the infusion, while at higher rates of infusion, the peak hydrogen response occurred after the end of the infusion. Although these results confirmed that monitoring breath hydrogen concentration usefully signalled the time taken for a meal containing unabsorbed carbohydrate to reach the colon, it did not reliably indicate the time when all of the meal had entered the colon. Finally, the use of the maximum increase in breath hydrogen concentration as an index of the degree of carbohydrate malabsorption assumes uniform rates of entry into the colon.

Diagnosis of bacterial overgrowth of the small intestine. Comparison of the 14C-D-xylose breath test and jejunal cultures in 60 patients.

Abstract: Sixty consecutive patients suspected of having bacterial overgrowth of the small intestine (BOG) had aerobic and anaerobic bacterial cultures made of fasting upper jejunal fluid and also a 14C-D-xy...

Value of the 14C-D-xylose breath test in patients with intestinal bacterial overgrowth

Abstract: 18 control subjects and 18 patients, with a variety of gastrointestinal conditions were investigated using a 10-muCi 14C-D-xylose breath test. The latter also underwent quantitative bacterial studies of fluid obtained by intestinal intubation. In 14 patients a smaller dose of 3 muCi 14C-D-xylose was compared to the standard dose and there was a good correlation between the two doses. The peak value of the 14C-D-xylose test provided the best discrimination between patients with and without bacterial overgrowth. The 14C-glycocholic acid test performed in 15 patients, although as sensitive, was less discriminating. The 14C-D-xylose breath test is reliable and more specific in confirming the diagnosis of small intestinal bacterial overgrowth without having to resort to direct bacterial studies.

[14C]aminopyrine breath analysis and conventional biochemical tests as predictors of survival in cirrhosis

Abstract: Twenty-eight patients with histologically confirmed cirrhosis were followed for up to 3.8 years after [14C]aminopyrine breath analysis. Survival rates were calculated by life-table method and outcome analyzed by log rank test. A normal breath test score was associated with a higher probability of survival than a low score, although the difference was not statistically significant. A normal serum albumin was a better predictor of outcome. Survival curves constructed according to the results of breath analysis and serum albumin differed in that the former appeared to predict early survival and the latter late survival. For this reason, data were reanalyzed by subjects' results for both tests. A normal breath test score and a normal serum albumin was associated with a significantly higher probability of survival than an abnormal result for either test.

Nuclear medicine liver function tests for pregnant women and children 1. Breath tests with 14C-methacetin and 13C-methacetin

Abstract: Stable isotopes, such as 13C, should be substituted for the long-lived radionuclide 14C in the 14C breath test when doing liver function tests in children and pregnant women. For comparison 13C, 15N-methacetin and 14C-methacetin were synthesized as suitable diagnostic agents. Methods are described for the measurement of 14C and 13C in the breath. After oral administration of labelled methacetin to healthy subjects and patients with liver diseases a good correspondence between 13C- and 14C-measurements in the same subject on the one hand, and a good discrimination between controls and patients on the other hand were shown. Findings with regard to 14C measurements in urine are discussed supporting the supposed advantage of 13C-methacetin over 14C-methacetin application.

The hydrogen (H2) breath test. Sampling methods and the influence of dietary fibre on fasting level.

Abstract: Three end-expiratory breath hydrogen (H2) sampling methods were compared in a patient group (n = 12) and a laboratory staff group (n = 12) on two separate occasions. H2 samples obtained with each method showed significantly different concentrations (p < 0.001) but no significant differences in coefficient of variation when individual triplicate samples were evaluated. There was a high correlation between the breath H2 concentrations obtained by the three methods (r = 0.93–0.96). Fasting breath H2 values after an overnight fast and an unrestricted diet the day before the investigation were compared with values obtained after an overnight fast and a low-fibre diet the day before the test in two patient groups (n = 39 and 39) with a comparable distribution of diagnoses and in one group of healthy volunteers (n = 17). Fasting breath H2 concentrations were significantly lower after a low-fibre diet in the patient groups (p < 0.005) and in healthy volunteers (p < 0.02). We conclude that each of the three end-ex...

Evaluation of gastrointestinal motility using the hydrogen breath test.

Abstract: The purpose of the study was to evaluate the validity of a model where intestinal transit is increased and decreased by motility modifying drugs. The measurement of breath hydrogen concentrations after ingestion of lactulose was used to estimate small intestinal transit time. After obtaining base-line values, eight healthy volunteers were pretreated on separate occasions with loperamide, diphenoxylate, metoclopramide and cisapride. Diphenoxylate caused a significant increase in small bowel transit time, whereas both metoclopramide and cisapride significantly shortened it. The H2 breath test therefore seems to accurately reflect the expected transit time. Loperamide did not alter significantly intestinal transit. Possibly this drug counteracts its own delaying influence on small bowel transit by hurrying gastric emptying. Alternatively, not enough time was allowed for it to exert its full effect.

Value of breath hydrogen analysis in management of diarrheal illness in childhood: comparison with duodenal biopsy.

Abstract: Breath hydrogen tests were carried out on 157 children either because they had chronic diarrhea or because they were on disaccharide-free diets. Lactose malabsorption was common in patients with postgastroenteritis syndrome (43%), and sucrose malabsorption was readily detected in patients with congenital sucrase-isomaltase deficiency. Secondary sucrose malabsorption and small bowel bacterial overgrowth were also detected. In predicting clinical response to dietary change, the breath hydrogen test, as we perform it, was clearly the most specific and sensitive and had a predictive accuracy of 96%. Duodenal biopsy results obtained from 48 of the children gave a 23% incidence of misleading disaccharidase results (16.7% falsely normal, 6.3% falsely abnormal), but biopsy remains vital in the diagnosis of congenital sucrase-isomaltase deficiency. False negative breath hydrogen results were obtained on occasions (4%) but in most instances were related to recent antimicrobial therapy or failure of the breath test mechanics (e.g., vomiting, length of sampling).

Hydrogen (H2) Breath Test and Gastric Bacteria in Acid-Secreting Subjects and in Achlorhydric and Postgastrectomy Patients before and after Antimicrobial Treatment

Abstract: Sixteen patients with pentagastrin-fast achlorhydria and 12 patients who had undergone Billroth II gastrectomy (at least 3 years previously) were compared with 10 acid-secreting volunteers and 13 patients with endoscopically proven peptic disease. The concentration and type of gastric bacteria were analysed in achlorhydrics, Billroth II patients, and patients with peptic disease. A 6-h hydrogen (H2) breath test after a standardized meal was performed in all subjects. The mean concentration of gastric bacteria was significantly higher in achlorhydrics and Billroth II patients than in patients with peptic disease. End-expiratory H2 excretion was elevated in achlorhydrics and Billroth II patients to levels significantly exceeding those of acid-secreting volunteers and patients with peptic disease. In achlorhydrics, total bacterial concentration in gastric juice was correlated to H2 excretion between 60 and 180 min after the meal. Treatment of achlorhydric and postgastrectomy patients with trimethoprim/ sulph...

Nuclear medicine liver-function tests for pregnant women and children. 2. A new test method via urine using 15N-methacetin.

Abstract: A simple, non-invasive, non-radioactive liverfunction test is proposed. After an oral dose of 3 mg 15N-methacetin per kilogram body mass, the kinetics of 15N excretion via urine were characterized by the quotient of the amounts of 15N excreted in two successive urine samples (Q value). The stable nitrogen isotope 15N was found to be an excellent and easily detectable indicator of the sum of all methacetin metabolites present in urine. Alterations in the nature or ratio of methacetin metabolites due to liver diseases could not be found. From the investigation of 11 men, 3 pregnant women and 15 children, a clear difference was observed in Q values of healthy persons and patients suffering from liver-cell-activity diseases. The discriminating power of our new liver-function test is shown to be equivalent to that of the 14CO2 breath test.

Hydrogen breath test in schoolchildren.

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

Effect of infant age on aminopyrine breath test results.

Abstract: The aminopyrine breath test has been used in adults as a measure of hepatic N-demethylase activity. In order to study maturational changes in enzyme function, 13C aminopyrine (2 mg/kg) was administered orally to infants (n = 16) between the ages of 1 and 38 wk. Breath samples were collected for 6 h after administration of the labeled aminopyrine for the measurement of 13CO2 enrichment. Using a number of different scoring methods to quantitate 13CO2 elimination of breath, demethylation of aminopyrine was found to be positively correlated to age. By 20 wk of age, some infants had rates of elimination similar to those measured in adults. Absorption was excluded as a limiting variable, because no improvement in oxidation rates was found when the aminopyrine was readministered as an intravenous bolus. Changes in nutritional status and route of feeding (enteral versus parenteral) did not prevent the effect of maturation on aminopyrine elimination. Conclusions: 1) maturational differences are seen in the metabolism of aminopyrine; 2) these differences may reflect immaturity of N-demethylase activity or diversion of the liberated formaldehyde into biosynthetic rather than oxidative pathways.

Accuracy of blood alcohol estimations obtained with a breath alcohol analyser in a casualty department

Abstract: The accuracy and reliability of a rapid blood alcohol estimation by means of a breath alcohol analyser has been evaluated under casualty department conditions in a series of 646 road-crash victims managed at the Dandenong and District Hospital. A higher correlation (r = 0.91) was found between the breath alcohol analyser readings in 633 casualties and those obtained by blood analysis in the police laboratory. In 13 unconscious casualties in whom a nasal breath test was performed, the correlation was lower (r = 0.76). In six casualties, the breath alcohol analyser readings showed lower alcohol concentrations than the legal limit of 0.05 g/100 mL (10.9 mmol/L), but blood analysis detected an illegal concentration. Further evaluation of the accuracy of the breath alcohol analyser in other casualty departments is necessary before it can be recommended as a screening device in States which have legislated for compulsory blood alcohol tests in adult road casualties. Language: en

The 1-g 14C-D-Xylose Breath Test in Gallstone Patients with and without Duodenal Diverticula

Abstract: To assess whether gallstone patients with duodenal diverticula have bacterial overgrowth in the proximal small bowel, the results of the 1-g 14C-D-xylose breath test were compared in 24 patients with duodenal diverticula and in 24 without diverticula. All patients had been treated with endoscopic papillotomy (EPT) for stones in the common bile duct before the study, and cholecystectomy had previously been performed in 20 patients. No significant differences between the groups were found concerning age, sex, and body weight. Cumulative 14CO2 expired in 3 h in percentage of administered dose of 14C-D-xylose was 8.55% (7.58-9.57%) and 7.38% (6.32-8.96%) in patients with and without diverticula, respectively (p = 0.06), indicating a higher bacterial activity in the small bowel in patients with duodenal diverticula than in those without diverticula. The results appeared to be influenced by cholecystectomy.

Random breath-testing.

Abstract: were being circulated within the Layton Inquiry to try and indicate that psychiatrists were earning a substantial amount per patient. If Dr Spielman reads what I wrote more carefully, he will understand that I was putting the case for the psychiatrists in question even quoting from the Australian and New Zealand Journal ofPsychiatry the fact about the potential cost savings to the community if psychotherapy were to be appropriately used. Dr Spielman's unequivocal assurance is noted, but why be so concerned? I believe I wrote that the difference between the educative and the therapeutic is often difficult to differentiate. PelerinLe Meilleur

[13C]Acetate oxidation in infants after oral versus rectal administration: a kinetic model.

Abstract: To study the fate of volatile fatty acids (VFA) in the large bowel, we compared the rate of oxidation of 13C-labeled VFA administered rectally with that of the orally administered substrate. On two different days, 1-[13C]acetate was administered rectally or orally to five infants recovering from diarrhea. Breath samples were collected over 4 h and analyzed for 13C enrichment of breath CO2 by gas isotope ratio mass spectrometry. The percent dose recoveries of 13C in breath were fitted to multicompartmental models using the SAAM-27 program. Following model development procedures, the oral acetate breath test curves could be accounted for only by a compartmental model in which labeled acetate underwent absorption into and mixed with a systemic pool before oxidation took place. The rectal acetate breath test curves could be accounted for by a simpler model in which oxidation occurred directly in the compartment in which the rectal acetate was administered, and required no rate-limiting absorptive process. Our results indicate that the labeled acetate was oxidized more rapidly when the substrate was administered rectally than orally. This observation points to the direct utilization of volatile fatty acids within the colon.

[Quantification of the drug-metabolizing enzyme system in liver diseases: a comparison between antipyrine saliva clearance and the aminopyrine breath test].

Abstract: The metabolic activity of the hepatic cytochrome P450 system was studied in 53 ambulatory subjects. 18 of these were cirrhotics and 23 had non-cirrhotic liver disease, documented by biopsy, serologic, ultrasound or computerized tomography findings, and characterized by quantitative liver function tests, such as galactose elimination capacity and indocyanine green fractional clearance. For comparison, 12 normal control subjects were also included. All subjects were given 10 mg/kg body weight antipyrine and saliva concentrations determined with an HPLC-method at 24 and 48 hours after dosing. Antipyrine saliva clearance (ASC) was calculated according to a two-point method (Cl1), and compared with a one-point method (Cl2) using the 24 h sample only. These subjects also underwent an aminopyrine breath test (ABT), breath samples being collected at regular intervals during 60 minutes following injection of a tracer dose of 1.5 muCi (14C-dimethylamino)antipyrine. Cl1 and Cl2 correlated strongly (r = 0.93). On the basis of smaller variations (particularly in control subjects), better definition of disease severity and convenience and time saving, Cl2 is to be preferred. Comparison of Cl2 with ABT showed that both procedures apparently quantify overlapping enzymatic activities. However, the relationship between Cl2 and ABT values, albeit highly significant (r = 0.72), suggests that only about half of the variables are subject to the same determinant. In addition, a positive intercept of the regression line extrapolated to the Cl2 axis points to quantitatively important extrahepatic breakdown of antipyrine. The results suggest that, in view of the wide variation in normal values (presumably in part influenced by exogenous pollutants), ASC only provides an approximation of hepatic metabolic activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorption and tolerance of lactose in infants recovering from severe diarrhea.

Abstract: Nineteen infants were challenged during their convalescence from severe diarrhea with a lactose-containing meal. Twenty-four hour intake, pre- and post-challenge breath H2 levels, clinical responses, and growth were measured at approximately biweekly intervals for 3 months beginning 1 month after hospital discharge. Ten lactose-tolerant infants were assigned randomly to receive one of two formulas similar in composition except for carbohydrates: lactose (Group L) (n = 6) and sucrose (Group S) (n = 4). Infants in Group L had greater intakes and growth rates during the initial 15 days of the study. No difference in weight for age z-scores was detected between groups at the end of the observation period. Infants in Group L had higher baseline and peak breath H2 levels indicating greater colonic carbohydrate fermentation than infants in Group S: however, breath H2 levels were not predictive of tolerance to lactose-containing meals. Carbohydrate absorption by infants in Group S appeared to exceed that of infants in Group L. Thus, colonic fermentation of malabsorbed carbohydrate may have prevented diarrhea and allowed acceptable rates of catch-up growth.

A simple method for routine determination of the metabolic liver capacity: the aminopyrine breath test.

Abstract: In 16 healthy volunteers and in 39 patients with liver diseases (fatty liver, chronic persistent and chronic active hepatitis, hepatic cirrhosis) a simplified aminopyrine breath test (ABT) was carried out using a "tracer" dose of 3 mg (111 kBq) 14C-aminopyrine. The exhaled 14CO2 measured 1 h after intake amounted to values between 771 and 1337 DPM/mmol CO2/70 kg body weight in healthy controls. The amount of exhaled 14CO2 decreased in the order: fatty liver greater than chronic, active hepatitis greater than active, compensated cirrhosis greater than active, decompensated cirrhosis. Between the values of ABT and various conventional laboratory liver tests (alanine-aminotransferase, alanine-aminopeptidase, aspartate-aminotransferase, gamma-glutamyltransferase, total serum bilirubin) significant correlations were found (r = 0.6019 to 0.7765, n = 55; p less than 0.001). The proposed modification of the breath test is of advantage in that it requires a very low dose of aminopyrine and is easily practicable.

[Fat utilization in newborn infants with and without heparin administration. Comparative study with the 13C-triolein breath test].

Abstract: The elimination of parenterally administered lipids from the bloodstream of premature infants can be accelerated by activation of the lipoprotein-lipase using heparin. We have no evidence that the free fatty acids increasing under enhanced lipolytical activity are utilized for energy production. For this reason, the oxidation rates of intravenously administered lipids in premature infants are examined both with and without heparin. Triolein marked with 13C and processed in soybean oil is administered intravenously at a dosage of 10 mg/kg. 13CO2 results from fatty acid oxidation and is exhaled through the lungs, whereafter it is collected in separate breath samples over a period of 6 hours and determined by mass spectrometry. The examination was performed in 5 premature infants, first without heparin, then after heparin injection (10 U/kg). The extent of 13CO2 exhalation was not significantly influenced by heparin. Without heparin supply we measured a fatty acid oxidation of 32.0 +/- 2.57% which was the same (31.6 +/- 2.34%) after heparin injection. Single intravenous administration of 10 U heparin/kg does not cause increased fatty acid oxidation in premature infants.

Small intestine transit time and lactose absorption during phototherapy.

Abstract: Diarrhea is often seen during phototherapy in jaundiced infants. Lactose malabsorption and reduced gut transit time (GTT) are some of the proposed explanations. However, the etiology of the diarrhea is still controversial. We investigated GTT and lactose absorption during phototherapy using the H2 breath test. Breath H2 was measured every 10 min for 150 min after feeding of jaundiced infants with and without phototherapy, and in controls. There were 12 newborns in each group. The time of increase of H2 excretion over 10 ppm was taken as the transit time. Lactose malabsorption was estimated by integrating the area under the excess H2 curve. No difference was found in GTT, lactose absorption, peak breath H2 and the time of the peak between phototherapy-treated infants and jaundiced and nonjaundiced infants. The results did not support the presence of lactose malabsorption during phototherapy and the decreased total GTT reported in the literature was not due to shortened small intestinal transit time.

Aminopyrine breath test and zonal hepatic damage in rats

Abstract: Acute hepatic damage in centrilobular or periportal areas was induced in two groups of rats by intraperitoneal injections of bromobenzene or allyl alcohol, respectively. The effect of this zonal damage on the demethylation of 14C-aminopyrine was evaluated by measuring the elimination of 14CO2 in breath following intravenous administration of a tracer dose of the labeled compound. In rats with centrilobular hepatic damage 14CO2 elimination in breath was significantly decreased compared to controls. In rats with periportal hepatic damage, elimination of 14CO2 in breath was unchanged. These results suggest functional heterogeneity of hepatocytes in vivo with respect to drug-metabolizing capacity.

Breath-test appliance with test body dispenser

Abstract: An appliance for checking the alcohol content of a person's breath using a test body into which the breath is blown and which can be connected to a test device enables people in any walk of life to be able to check their own alcohol content on any occasion. The appliance has a housing which contains, in addition to the test device known per se, an automatic dispenser which can be actuated when money is inserted and which delivers test bodies individually, and located in a housing wall a connection element serving for connecting the test body to the test device.

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

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