Search PubMed⌕ Search

Biomedical subjects

C Beckers

Publications and source records attributed to C Beckers.

At least 19 recordsLinked to original sources
PubMed1992

Influence of ureteral status on kidney washout during technetium-99m-DTPA diuresis renography in children.

To assess the influence of the ureter on renal washout during 99mTc-DTPA diuresis renography, ureteral images were reviewed in 42 children (median age: 5 mo) referred for hydronephrosis. Sixty-minute acquisitions were obtained in hydrated patients under bladder drainage. Furosemide was injected at 30 min. An abnormal ureter was defined as an intense and continuous image of greater than 10 min. A washout index was determined on renal (KT1/2) and ureteral (UT1/2) curves. Curve patterns corresponding to normal (type I), obstructive (II) and nonobstructive (III) cases were described. Compared with the x-ray data, diuresis renography was highly sensitive (91%) and specific (98%) for detecting any abnormality. Despite an obstructive KT1/2 (greater than 20 min), no patient with an abnormal ureter underwent therapy at the ureteropelvic junction. After surgery at the lower level, hydronephrosis regressed. Our data indicate that abnormal ureter findings at diuresis renography have to be recognized before planning therapy for children with hydronephrosis.

Adolescent↗
PubMed1991

Noninvasive measurement of liver regeneration with positron emission tomography and [2-11C]thymidine.

The feasibility of liver regeneration determination with [2-11C]thymidine and positron emission tomography was investigated in partially hepatectomized rats. Serial tomographic scans were performed over a 120-minute period after injection of [2-11C]thymidine together with tritium-labeled thymidine. Within 10 minutes after injection, positron emission tomography scans showed a twofold higher hepatic uptake in regenerating than in nonregenerating livers. Time-activity curves over the liver area indicated that the maximal uptake was followed by a faster decrease of 11C radioactivity in controls than in regenerating animals, so that total 11C activity remaining in the liver at 120 minutes accounted for 68% of maximum in regenerating and only 38% in controls. Tissue distribution studies performed at 120 minutes showed that total 11C radioactivity, expressed in percent injected dose per gram, was six times higher in regenerating livers than in controls (0.62% +/- 0.07% in regenerating livers and 0.10% +/- 0.03% in nonregenerating livers; P less than 0.001) and correlated with 3H radioactivity measured in the nuclear fraction (r = 0.92; P less than 0.001). When the hepatic uptake was expressed in percent of dose per organ, the difference between both groups increased (2.31% +/- 0.23% in regenerating livers and 0.29% +/- 0.02% in nonregenerating livers; P less than 0.001) because of higher weight of regenerating livers than of nonregenerating livers (3.83 +/- 0.11 g in regenerating livers and 2.96 +/- 0.16 g in nonregenerating livers; P less than 0.001). In other organs examined, no difference in 11C radioactivity was found between the two groups of rats. These results indicated the potential usefulness of [2-11C]thymidine and positron emission tomography for noninvasive measurement of liver regeneration.

Animals↗
PubMed1979

Thyroid nodules.

Explore the source record for details and available documents.

Animals↗
PubMed1979

Screening for neonatal hypothyroidism by thyroxine and thyrotrophin radioimmunoassays using dried blood samples on filter paper.

A routine and automatized methodology for thyroxine (T4) and thyrotrophin (TSH) radioimmunoassay (RIA) using dried blood samples on filter paper is described. T4-RIA was performed on one single dot (5 mm diameter equivalent to 4 microliters of serum) while two dots were necessary for TSH-RIA. Reference filter papers were introduced in each assay for quality control. In a preliminary study on 4,155 neonates, samples generally obtained between the 5th--7th day gave a mean 'dot-T4' of 97.95 +/- 36.04 nmol/l and a mean 'dot-TSH' of 10.19 mU/l +/- 8.25, corresponding to 2.47 mU/l of serum. Within an 18-month period (November 1976-April 1978), a total of 16.522 neonates have been screened allowing detection of three cases of congenital hypothyroidism (incidence 1 : 5507), two cases of congenitally low TBG and thirty-three cases of transient hypothyroidism.

Female↗
PubMed1979

In vitro binding of various biological substances by two hypocholesterolaemic resins. Cholestyramine and colestipol.

The ability of cholestyramine and colestipol, two hypocholesterolaemic resins, to bind in vitro several compounds such as vitamin B12, vitamin B12-intrinsic factor complex, folic acid, iron citrate and calcium chloride was investigated. Both resins bound to a high extent vitamin B12-intrinsic factor complex, folic acid and iron citrate; in addition, cholestyramine also caused appreciable binding of calcium. Throughout a large range of pH, there was no change in the binding capacity; however, at pH 2, cholestyramine exhibited a marked drop in the binding of tested substances (with exception of folic acid). By increasing the molarity of the solutions, the binding to the resins of vitamin B12-intrinsic factor complex and of calcium chloride was completely inhibited. In human gastric and duodenal juices, the uptake by the resins of the studied compounds depends on the molarity of the physiological medium tested and partly confirms the results obtained with aqueous solutions. These data obtained in vitro emphasize the necessity of regular monitoring these biochemical parameters during chronic treatment of hypercholesterolaemia conducted with these two resins.

Body Fluids↗
PubMed1978

Quantitation of human serum antithyroglobulin antibodies by a two-site radioimmunoassay.

A two-site solid-phase radioimmunoassay for measuring serum antithyroglobulin antibodies applicable to human serum is described. The sequential steps of the procedure include the adsorption of thyroglobulin (Tg) on polystyrene tubes and the binding of the antithyroglobulin antibody to solid phase followed by the fixation of labelled thyroglobulin. The optimal experimental conditions for the adsorption of unlabelled Tg, the uptake of the antibodies and the fixation of labelled Tg have been defined. The test is specific for antithyroglobulin antibody and its reproducibility and precision are satisfactory. The radioassay showed a good correlation with the hemagglutination method and, also, was found to be more sensitive. Levels of antithyroglobulin IgG in positive sera ranged from 0.3 microgram/ml to several mg/ml. In contrast to the double antibody radioimmunoassay for antithyroglobulin antibodies, this solid-phase radioassay is easier to perform; moreover, it is relatively independent of the quality, the purity and the specific activity of the tracer.

Antibodies↗
PubMed1978

Demonstration of an ecdysteroid receptor in a cultured cell line of Drosophila melanogaster.

Incubation of the high-speed supernatant from the Kc cell line of Drosophila melanogaster with [3H]ponasterone A results in significant binding of the ligand as determined by gel filtration and dextran-coated charcoal binding assays. In vivo exposure of the Kc line to [3H]ponasterone A for 30 min results in a marked binding of the ligand by a KCl-soluble nuclear extract. With both the cytosol and nuclear preparations the binding has specificity and a low dissociation constant (3 X 10(-9) M). In addition the labeling of the nuclear preparation exhibits a saturation at approximately 7 X 10(-10) M which probably reflects the molar concentration of cytoplasmic receptors.

Binding, Competitive↗
PubMed1978

Thyroid iodide clearance and radioiodide uptake in protein-calorie malnutrition.

The thyroid function was evaluated in two comparable groups of 12 protein-calorie malnourished children respectively by oral and intravenous test using radioiodine 131I. Maximal radioiodide uptake (RAIUmax) peaked within 24 hr in the intravenously investigated children, but only after 48 hr in the orally investigated children. In both protein-calorie malnutrition groups, the mean RAIUmax was significantly decreased by comparison with the mean normal RAIUmax (P less than 0.01). In protein-calorie malnutrition children, the RAIU curve reached intermediate values ranging from subnormal to about nearly half the normal. Thyroid clearance was early depressed and in some cases, dropped to values as low as one tenth of the normal mean (P less than 0.001), reflecting a severe thyroid involution. There is a high correlation between the RAIUmax and thyroid clearance values (r = 0.95); the regression line is defined by the equation Y = 1.12X + 17.08. Both functional parameters of thyroid activity appear to be mainly lowered in relation to the duration of protein deficiency.

Child, Preschool↗
PubMed1978

'Low T3 syndrome' in patients chronically treated with an iodine-containing drug, amiodarone.

Cardiac patients treated with the iodine-containing drug 'amiodarone' undergo a significant iodine overload which can last for months after the drug has been withdrawn. Some patients develop hyperthyroidism and others hypothyroidism. In the hyper- or hypothyroid patients, the indices of thyroid function are modified as usually observed in these situations. In the patients remaining euthyroid while taking amiodarone or after its withdrawal, but still under its influence as shown by the iodine overload, a 'low-T3 syndrome' is observed, this state being characterized by a high total T4, a low free T4, a normal T3 resin uptake, a low total T3, a normal free T3, a high r-T3 and a relative TSH-unresponsiveness to TRH.

Amiodarone↗
PubMed1978

A radioimmunoassay for arthropod moulting hormones, introducing a novel method of immunogen coupling.

Inokosteron-26-oic acid was coupled to thyroglobulin in aqueous pyridine by a water-soluble carbodiimide. After exhaustive dialysis and gel filtration on Sephadex G-25 in the presence of sodium dodecylsulfate, a coupling ratio of 164 haptens per molecule of thyroglobulin was determined. In all three animals injected with the conjugate, ecdysone-binding antibodies were detected. After one booster injection the antiserum could be diluted 1 : 5000 (1 : 4000, or 1 : 2000) in order to get a 50% binding of [3H]ecdysone. The dissociation constant was calculated as 5.8 X 10(-10) MOL/L. The antiserum has a greater affinity for ecdysone and 22-isoecdysone than for all other ecdysteroids and steroids tested.

Animals↗
PubMed1978

Clinical evaluation of Tc-99m-diethyl-IDA in hepatobiliary disorders.

N,alpha(2,6-diethylacetanilide)-iminodiacetic acid is a new Tc-99m-labeled radiopharmaceutical primarily excreted through the biliary tract. Its high concentration in the bile allows the imaging of the biliary tree and the gallbladder. Scintigraphic studies were performed in 20 normal subjects and 42 patients suffering from various hepatobiliary disturbances. In normal subjects, the early liver uptake was followed by the accumulation of the tracer in the intrahepatic bile ducts and the gallbladder before its discharge into the duodenum. In cases of hepatocellar damage, the hepatic accumulation of the tracer was clearly depressed. Any acute or subacute disorder of the gallbladder was clearly demonstrated by Tc-99m-diethyl-IDA. In cases of asymptomatic cholelithiasis, we observed delayed visualization of the gallbladder associated with its decreased accumulation of the tracer. The intrahepatic bile ducts were distended in cases of incomplete obstruction of the hepatobiliary ducts, whereas they were never visualized when there was severe hepatocellular damage or complete obstruction of the biliary tree.

Bile Ducts, Intrahepatic↗