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At least 19 recordsLinked to original sources
PubMed1979

Triolein breath test: a sensitive and specific test for fat malabsorption.

In order to develop a simple and accurate screening test for steatorrhea, the authors compared quantitative stool fat excretion with breath excretion of 14CO2 after the ingestion of 14C-labeled trioctanoin, tripalmitin, or triolein. The study group included 24 nonobese subjects without steatorrhea but with diarrhea secondary to irritable bowel syndrome and 40 subjects with steatorrhea. The triolein breath test provided the most reliable discrimination, with 100% sensitivity and 96% specificity. The trioctanoin and tripalmitin breath tests were sensitive, but lacked specificity (69% and 58% false-positive results, respectively). Three of the 12 obese patients with irritable bowel syndrome had false-positive triolein breath results. In detecting steatorrhea, the triolein breath test was moderately superior to the measurement of serum carotene and to qualitative stool fat. Thus, the triolein breath test appears to be a sensitive, specific, noninvasive, and relatively simple screening test for the detection of steatorrhea.

Adult↗
PubMed1992

Limitations of the triolein breath test.

Patients being investigated for intestinal absorptive capacity were classified as normals or malabsorbers on the basis of three fat absorption tests. Malabsorbers were further classified as mild, moderate, severe or gross according to severity of malabsorption. Using this classification system the triolein breath test was evaluated in 53 patients. Seventeen patients were excluded because their graph of percentage breath [14C]carbon dioxide versus time was exponential indicating that the peak [14C]-carbon dioxide may be occurring later than the six hour duration of the test. The sensitivity and specificity of the triolein breath test were found to be 100% and 96%, respectively and moderate correlations with the individual fat absorption tests were found. However, the breath test was limited in its capacity to predict the severity of malabsorption. Carbon dioxide output was also measured in order to determine the applicability of using an assumed value. The respiratory quotient and variability of results were high in nineteen patients indicating possible hyperventilation. In 32 patients with reproducible results and normal respiratory quotients the average carbon dioxide output was 8.66 mmol/kg per hour with a wide range of 5-12.4 mmol/kg per hour. Consequently the use of an assumed carbon dioxide output can introduce considerable errors in the triolein breath test. This study highlights drawbacks of the triolein breath test, particularly problems in using an assumed carbon dioxide output for its calculation, its inability to predict the severity of malabsorption and the nature of the dietary load used.

Adolescent↗
PubMed1979

Effects of tristearin, triolein and safflower oil diets on cholesterol balance in rats.

Diets containing relatively homogeneous triglycerides composed of 18-carbon chain saturated, monounsaturated or polyunsaturated fatty acids were fed to rats. Cholesterol absorption and turnover were studied. Cholesterol absorption was significantly less in rats fed tristearin than in animals fed triolein or safflower oil. Cholesterol removal from plasma was fastest in rats fed tristearin and slowest with safflower oil and triolein. Plasma cholesterol levels were lowest with tristearin and highest with safflower oil. Increased cholesterol in high density lipoproteins was observed with tristearin and triolein. Lymph and hepatic cholesterol, and lymph triglycerides were highest with safflower oil, suggesting endogenous mobilization. Cholesterol production was least with triolein. Sterol synthesis was greatest with tristearin, perhaps attributable to decreased negative feedback analogous to effects of cholestyramine. Differences in lipoprotein composition observed with the various diets are important since effects on particle size and shape may influence removal mechanisms. The mechanisms underlying the different effects of dietary triglycerides on sterol absorption and metabolism remain to be elucidated.

Animals↗
PubMed1978

Intestinal lymph chylomicron cholesteryl ester during duodenal triolein infusion at increasing rate.

Chylomicron lipid composition in mesenteric lymph fistula rats was followed during duodenal triolein infusion at three rates. Esterified cholesterol decreased progressively in all groups as triglyceride transport continued, and the rate of decrease was reciprocally related to the triolein infusion rate. Suppression of cholesterol ester synthesis may spare unesterified cholesterol for chylomicron membrane formation. Ratios of triglyceride to phospholipid and to unesterified cholesterol increased with the duration of triglyceride secretion, while the chylomicron surface lipid composition remained constant over time. The rate of increase in the core:surface lipid ratios was the same irrespective of the triolein transport rate.

Animals↗
PubMed1975

Effect of partial constriction of the superior mesenteric artery upon absorption of d-xylose, labeled triolein and labeled albumin.

Intestinal adsorption of triolein, Risa and d-xylose was determined before and after reduction of blood flow in the superior mesenteric artery. Absorption of d-xylose did not change, but absorption of triolein and Risa appeared to be slightly improved after arterial constriction, even if the artery was completely thrombosed. Enhancement in absorption of Risa and triolein was probably the result of extensive collateral formation around the constricted superior mesenteric artery.

Animals↗
PubMed1975

Effects and distribution of acute fat embolism in spontaneously breathing dogs using radioactive carbon triolein.

The acute effects of a triolein infusion in dogs were secondary to the mechanical effects of this neutral fat which was distributed in the pulmonary and systemic vascular tree of all organs without inflammatory change. Hypoxia developed immediately and became progressively worse as the infusion was continued. Pulmonary hypertension developed during the fat infusion without pneumonia, congestive heart failure or pulmonary edema. There was a slow leak of 14C triolein into the systemic circulation rather than a rapid shower, and this radioactive fat was recirculated between the pulmonary and systemic vasculature. Seventy-six per cent of the 14C triolein was retained in the lungs. Terminally, the dogs had a respiratory arrest without cardiac decompensation, cardiac arrest or pulmonary edema; cerebral fat embolism in addition to severe hypoxia appears to be the cause.

Acute Disease↗
PubMed1978

Intestinal absorption of griseofulvin from a triolein digestion mixture in rats.

The intestinal absorption rate of dissolved griseofulvin was determined from: (a) an aqueous phase, (b) an aqueous phase containing a micellar phase composed of taurodeoxycholate, monoolein, and oleic acid, and (c) an aqueous phase containing the micellar phase and emulsified triolein. The triolein digestion mixtures were recirculated through 20-cm segments of in situ rat jejunum. Lipid concentrations were maintained constant by infusing the lipids into the digestion mixture at the same rate as they disappeared. Griseofulvin distribution among the aqueous, micellar, and oil phases was determined by solubility and equilibrium dialysis experiments. Analysis with a linear kinetic model indicated that griseofulvin absorption from the micellar and oil phases was negligible compared to its absorption from the aqueous phase.

Animals↗
PubMed1992

Lateral interactions of pig apolipoprotein A-1 with egg yolk phosphatidylcholine and with cholesterol in mixed monolayers at the triolein-saline interface.

Interfacial tensions of egg yolk phosphatidylcholine (PC) and cholesterol monolayers adsorbed at the triolein-saline interface were measured in the presence and absence of pig apolipoprotein A-1 (apoA-1) in the saline phase. In the absence of apoA-1, the adsorptions of PC and cholesterol at the interface from the triolein phase are cooperative, showing large lateral attractive interactions between the PC molecules and the cholesterol molecules in the monolayer. In the presence of apoA-1, the PC adsorption is anti-cooperative, indicating strong lateral attractive interactions between the PC and the apoA-1 molecules, i.e., apparently, repulsive lateral interactions between the PC molecules. On the other hand, lateral interactions of very low magnitude are observed between the cholesterol and apoA-1 molecules in the monolayer. Values of the lateral interaction energy are evaluated from the adsorption data by the Defay-Prigogine-Flory theory of monolayers. The large difference in lateral interaction energy with apoA-1 between PC and cholesterol in a mixed monolayer is discussed in connection with current problems in lipoprotein catabolism: reverse cholesterol transport, alterations in affinity of lipid particles to apoA-1, and formation of high-density lipoproteins and abnormal lipoproteins.

Adsorption↗
PubMed1979

Serum radioactivity of 14C-triolein and 3H-oleic acid ingested in a test meal:a rapid test of pancreatic exocrine insufficiency.

A double-tracer technique to estimate lipid digestion was investigated. 3H-labelled oleic acid and 14C-labelled triolein were ingested in a test meal. The serum radioactivity of 3H after ingestion of labelled oleic acid depends on absorption and metabolism of free fatty acids, while serum radioactivity of 14C from triolein, in addition to the former, depends on triglycerol digestion. This study shows that the ratio between 3H and 14C 2h after the test meal gives a good qualitative and quantitative estimation of lipid digestion: the 3H/14C ratio in patients with maldigestion is significantly higher than for normals (P less than 0.01), the predictive value of the 3H/14C ratio in the diagnosis of maldigestion is high, that of a positive result being 1.0 and that of a negative 0.93, and quantitatively the 3H/14C ratio shows a highly significant correlation with faecal fat (P less than 0.001). The test is very easy to perform, lasts for only 2 h, and is without discomfort to the patient or nursing and laboratory staff. It gives information like or superior to that of faecal fat measurement.

Adult↗
PubMed1978

Properties of cholesteryl oleate and triolein in mixed monolayers at the air-water interface.

The properties of cholesteryl oleate and triolein in mixed monolayers at the air-water interface have been measured between 24 and 37 degrees C. Analysis of force-area curves obtained as a function of the mol fraction of cholesteryl oleate indicates that at relatively low surface pressures these compounds are miscible in two dimensions up to a limit of about 0.5 mol fraction. At higher pressures either cholesteryl oleate or both lipids are expelled from the monolayer to form a bulk phase which is in rapid equilibrium with the surface phase. In the monolayer phase, orientation of the ester function of cholesteryl oleate is toward the aqueous phase, interaction with triolein is minimal, and packing is uniform over the solubility range. This together with the susceptibility of the cholesteryl oleate to enzymatic hydrolysis, suggests the applicability of monolayer systems to the study of cholesterol esterase activity. Comparison of our results with the bulk properties of these lipids suggests that the expelled cholesteryl oleate exists as a smectic mesophase and thus the system may provide a model for studying the transfer of molecules between the interior and surface of lipid deposits of the type found in atherosclerotic lesions.

Cholesterol Esters↗
PubMed1992

Inhibition of repairable DNA-damage in Escherichia coli K-12 cells recovered from various organs of nitrosamine-treated mice by vitamin A, phenethylisothiocyanate, oleic acid and triolein.

The influence of various dietary constituents--phenethylisothiocyanate (PEITC), oleic acid (OA), triolein (TO), and vitamin A (ROL)--on the genotoxic activity of nitrosamines (NDMA, NDELA, NPYR) was investigated. For this purpose differential DNA repair assays with Escherichia coli K-12 strains were performed in vitro and in vivo with mice. Under in vitro conditions (liquid holding), all compounds reduced nitrosamine induced DNA-damage in the indicator bacteria in the dose range 1-10 micrograms/ml, the ranking order of efficiency being PEITC greater than OA greater than ROL greater than or equal to TO. In animal-mediated assays, acute oral treatment with PEITC (17-150 mg/kg), 2 h before nitrosamine administration, resulted in a marked decrease of nitrosamine genotoxicity in liver, kidneys, lungs and in the blood. Also in other organs (spleen, testes) an increase in differential survival (which serves as a measure for repairable DNA damage) occurred. With ROL only a comparatively moderate antigenotoxic effect was obtained at a high dose level (250 mg/kg) under identical experimental conditions. OA (2000 mg/kg) and TO (16,000 mg/kg) were completely inactive. Upon repeated treatment (consecutive oral administration of the putative antigenotoxins over 4 days, a final treatment 24 h before nitrosamine administration) PEITC (150 mg/kg/day), ROL (80 mg/kg/day) and OA (2000 mg/kg/day) had no influence on the genotoxic effects of the nitrosamines. Repeated treatment with TO (4000-16,000 mg/kg/day) resulted in a moderate dose-dependent reduction of NDMA-induced DNA-damage in the indicator bacteria, whereas in combination with NPYR only a marginal effect was observed. Biochemical experiments indicated that the antigenotoxic effects of PEITC seen under in vivo conditions were due to inhibition of alpha-hydroxylation of the nitrosamines, whereas ROL and TO appeared not to interfere strongly with this metabolic activation step. Our results indicate that in vitro assays do only partly reflect the antigenotoxic properties of the different food constituents in vivo and that animal-mediated DNA repair assays with E. coli strains are an appropriate approach to study the effects of modifiers of nitrosamine genotoxicity in the living animal.

Animals↗
PubMedDate not supplied

Measurement of fat absorption utilizing 131iodine-triolein and nonabsorbable radioactive markers.

To eliminate many of the practical problems inherent in the collection of feces and in the chemical determination of fecal fat, a radioactive marker (131Ba) was combined with a labeled fat (131l-triolein) to measure fat absorption in man. The ratios of radioactivity of 131Ba/131l in a prepared capsule and that found in a random "grab" stool specimen after oral administration of the capsule were compared to determine the amount of fat absorbed. In an initial 36 patients, this double-label technique accurately separated normal from abnormal fat absorption as determined by the usual methods of quantitative fecal fat measurement. Results in an additional 102 patients and in 26 normals accurately reflected their clinical states. In addition, in vitro studies demonstrated more complete recovery of added lipid (99 percent) by radioactive techniques than by chemical analysis (86 per cent). The double-label technique not only seems more accurate than usual quantitative fecal fat determinations, but also greatly simplifies the measurement of fat absorption in man by eliminating the need for special diets, quantitative stool collections, and chemical analysis of stool.

Barium↗
PubMed1975

Idiopathic chylopericardium: 131-I-triolein scan for noninvasive diagnosis.

We report idiopathic chylopericardium in a physically active, asymptomatic 29-year-old man. Preoperative diagnosis was made by external cardiac imaging after oral administration of 131-I-labeled triolein. To our knowledge this is the first report of preoperative noninvasive diagnosis of chylopericardium. After open drainage and pericardial biopsy, the patient is asymptomatic without recurrence after 8 months.

Adult↗
PubMed1992

Spectrophotometric determination of lipase activity in the presence of increased triolein concentration.

A novel approach for the determination of pancreatic lipase (EC 3.1.1.3) activity by a spectrophotometric method is described. Enzyme activity is measured in the presence of 1 mmol/l triolein, a concentration much higher than usually employed in turbidimetry. The primary reaction medium is optimized as regards bile salt and colipase concentrations. The released fatty acids are enzymatically determined via a secondary reaction scheme using the constituents of a commercially available kit. The proposed method is easy to perform and may prove useful in determining lipase activity of standard lipase preparations, which is required for indirect assays. In addition to satisfactory precision and linearity as well as close correlation with other lipase assays, the procedure described in the present paper by-passes a number of short-comings (eg uncontrolled increase in absorbance) inherent to the turbidimetric methods.

Adult↗
PubMed1977

Estimation of fat absorption from single fecal specimens using 131I-triolein and 75Se-triether. A study in rats with and without induced steatorrhea.

The simultaneous use of 131I-triolein and 75Se-triether, a nonabsorbable marker, in a single oral dose to estimate fat absorption from incomplete fecal collections was tested in rats with and without induced steatorrhea. The results in normal rats showed that analysis of single stool samples allows a valid estimate of fat absorption as defined by the balance study based on the total fecal recovery of 131I. However, in the few normal rats with poor absorption, the absorption values from successively excreted stools showed a tendency to increase. Similar findings were obtained from biliary fistula rats with marked steatorrhea. No evidence of different intestinal transit rates of test fat and marker was observed in bile-diverted rats, thus suggesting that the observed inconsistency in fat absorption values from different stool specimens reflects intraprandial differences in the absorption of fat. Studies on rats subjected to intestinal ischemia do not support the suggestion of others that separation of fat and triether will occur if a mucosal defect is involved as the cause of fat malabsorption. It is concluded that this dual isotope technique may be of value in the clinical estimation of fat absorption, as it offers important technical advantages over conventional fat balance studies.

Animals↗
PubMed1977

Diagnosis of chylothorax with 131I-triolein: case report.

Communication between the thoracic duct and the pleural space can be demonstrated after oral administration of radiolabeled triglycerides or fatty acids of suitable chain length. A case of chylothorax was confirmed in this manner using 131I-triolein. The technique may be most useful in cases where the chylous nature of a pleural effusion is not apparent on inspection of the pleural fluid.

Adult↗
PubMed1979

Validation of a procedure for exogenous isotopic labeling of lipoprotein triglyceride with radioactive triolein.

A procedure has been developed for the exogenous isotopic labeling of triglyceride-rich lipoproteins (chylomicrons and very low density lipoproteins) using high specific activity radioactive triglyceride in the presence of aqueous dimethyl sulfoxide. The labeled product lipoproteins showed unchanged chemical and physical properties. When the particles had also been labeled biologically by incorporation of unesterified fatty acids into the triglycerides of lipoproteins secreted by liver or intestine, both endogenous and exogenous labels were removed at the same rates in the isolated perfused heart and liver or in intact or functionally hepatectomized rats. These experiments additonally indicated that the triglyceride fatty acid composition of chylomicrons and very low density lipoproteins was unchanged during triglyceride depletion in the peripheral tissues. Using such labeled lipoproteins it has been shown that uptake of remnant lipoprotein cholesteryl ester and triglyceride by the liver is simultaneous. The labeling procedure described should prove suitable for kinetic studies of the disposition of the various lipoprotein non-polar ('core') lipids.

Animals↗