USE OF LABELLED TRIOLEIN, VITAMIN A, AND D-XYLOSE IN THE DIAGNOSIS OF MALABSORPTION.
This paper discusses the type of results given by a group of test procedures used in the study of small intestinal dysfunction. While the chemical estimation of faecal fat remains the most valuable criterion for the laboratory detection of malabsorption, the occurrence of abnormal faecal or blood radioactivity also denotes the presence of malabsorption, although some patients with staetorrhoea appear to ;absorb' labelled triolein normally. Analysis of data from the other tests shows that steatorrhoea is not necessarily present in patients who give abnormal results and that the presence of malabsorption does not preclude a normal capacity for handling the test substances. These reservations impair the value of the vitamin A and xylose ;tolerance' tests and serum carotene levels as screening procedures for the determination of malabsorption states. On the other hand, these tests show patterns of results which are useful in differentiating idiopathic from secondary steatorrhoea, since patients with secondary malabsorption often handle one or more of these test substances normally. (+info)
THE LACK OF SELECTIVE REINCORPORATION INTO TISSUE PROTEIN OF THE AMINO ACIDS DERIVED FROM THE CATABOLISM OF SERUM PROTEIN.
Homologous S(35)-labeled albumin, gamma globulin, and alpha-beta globulin were transfused into rabbits and the specific activities of the electrophoretic fractions of the sera of the recipients were determined at various time intervals up to 12 days after injection. Detectable reincorporation into a fraction other than that transfused was found only in the gamma globulin fraction after albumin injection. This activity rose between 2 and 12 days and reached a level of 2 to 3 per cent of the extrapolated zero time activity of the albumin fraction. When homologous serum protein doubly labeled with I(131) and S(35) was transfused into mice, marked drops in the ratios of I(131) to S(35) in the serum and tissue proteins were observed between 1 and 48 hours after injection. On the basis of a determination of the absolute and relative amounts of I(131) and S(35) found in the various tissue and serum proteins, the amount of reincorporation of S(35) into each protein was calculated. The relative amounts of reincorporation of S(35) among the various tissues were remarkably similar to the relative amounts of incorporation of S(35) after the injection of labeled free amino acids. It is concluded that serum protein does not form a major direct source of amino acids to the tissues but feeds them indirectly through the extracellular pool. (+info)
Both synthetic and catabolic processes determine the serum gamma-globulin level. The rate of gamma-globulin synthesis appears to be the primary factor determining the amount of serum gamma-globulin. Increase of gamma-globulin synthesis (as may occur following immunization or development of plasma cell tumor) elevates the serum gamma-globulin level. This, in turn, accelerates the fractional rate of gamma-globulin catabolism. The change in catabolic rate reduces the dimensions of the serum change from that which would occur if synthesis alone determined the serum gamma-globulin level. The present studies indicate the existence of a homeostatic mechanism controlling the rate of gamma-globulin catabolism. The mechanisms of gamma-globulin catabolism are specific and selective. Marked serum increase of other immunoglobulin components (beta(2A)-globulins and gamma(1)-macroglobulins) do not accelerate gamma-globulin catabolism. Similarly, serum albumin increases do not influence gamma-globulin catabolism. The site determining gamma-globulin catabolism is restricted to a part of the gamma-globulin molecule; i.e., on the F piece obtained by papain digestion and, by inference, on the H chains obtained by reduction and alkylation of gamma-globulin molecules. (+info)
A SIMPLE TECHNIQUE USING 'DIALYSABLE' THYROXINE FOR ASSESSMENT OF THYROID STATUS.
A simple method for assessing thyroid status is described in which the percentage of radioactive thyroxine dialysed through a semi-permeable membrane between plasma samples is estimated. The results compare favourably with other tests in vitro. (+info)
A COMPARISON OF LABORATORY TESTS IN THE MALABSORPTION SYNDROME.
Absorption of radioiodinated triolein was tested in 93 individuals (15 controls, 28 cases of functional diarrhea, and 50 patients with suspected or manifest malabsorption syndrome).The results so obtained were compared in 59 cases with estimations of fecal radioactivity and chemically determined fecalfat excretion. A highly significant correlation was found.The urinary xylose excretion test was performed in 96 individuals. The diagnostic value of the radioactive fat absorption test was compared with that of the xylose excretion test in 78 cases. Both tests were diagnostic in cases of non-tropical sprue, but the xylose excretion test reflected the clinical improvement more accurately in treated cases. The radioactive fat absorption test was more reliable in the diagnosis of malabsorption secondary to bowel resection than was the xylose excretion test, but the converse was true in the diagnosis of malabsorption secondary to gastrectomy. The simultaneous use of these two tests was found to be a simple and reliable screening procedure. (+info)
SCINTILLATION SCANNING OF BRAIN TUMORS.
Brain scanning by means of externally placed moving scintillation detectors has proven to be an easy accurate method for demonstrating size, shape and position of many types of brain tumors. In a series of 53, there were few false negatives and few false positives. The procedure is easy on the patient, does not require anesthesia and can be done on outpatients. It is recommended as a screening procedure for all brain tumor suspects. (+info)
A RADIOIODINATED AZO DYE WITH AFFINITY FOR AMYLOID: A PRELIMINARY REPORT.
Investigation was undertaken to produce a radioactive material with affinity for amyloid tissue. Studies of a number of major dyes using paraffin histological sections of an amyloid spleen as test material showed that the only compounds with marked affinity for amyloid were watersoluble disazo dyes of the type E<--D-->E, where D is usually benzidine, o-tolidine or o-dianisidine, and E is a naphthol or aminonaphthol sulfonic acid. Substitution of an amino or a hydroxyl group in position 1 of the naphthalene nucleus caused loss of staining affinity. It was found that trypan blue could be radioiodinated at position 8 using the Sandmeyer reaction, and the labelled dye showed excellent staining and radioautographs of the test amyloid section. Metabolism of the tagged dye using 10-200 mug./kg. in animals showed minimal organ uptake, except for the liver which accumulated 30-40% of the injected dose by the end of four days. Use of this material in the diagnosis of human amyloid disease is being explored. (+info)
TRIOLEIN-I-131 TOLERANCE IN PATIENTS WITH CORONARY HEART DISEASE.
The value of the oral triolein-I(131) "tolerance" test in the study of patients with coronary heart disease was assessed. Thirtynine patients were divided into three groups: those with clinical evidence of coronary heart disease, those with increased risk, and those with no increased risk of coronary heart disease. The variability of the results precluded differentiation between the groups on the basis of this test. A minority of the patients with coronary heart disease showed strikingly elevated blood levels of lipid-bound radioactivity following the oral ingestion of triolein-I(131). It was concluded that this test is of no use in the diagnosis of coronary heart disease but may identify those patients with coronary heart disease who dispose of orally ingested fat in a grossly abnormal fashion. (+info)