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D Collet-Cassart

Publications and source records attributed to D Collet-Cassart.

23 records · Page 2Linked to original sources

The clinical relevance of ferritin concentration in the cerebrospinal fluid.

By means of a new technique (Particle Counting Immunoassay), we have determined the level of ferritin in 470 samples of cerebrospinal fluid of patients with various neurological disorders. The median value obtained in a control group was 2.3 ng/ml with an upper limit at 5.5 ng/ml. the concentrations in the serum and cerebrospinal fluid were independent, but that in cerebrospinal fluid correlated with its total protein content. High values of ferritin were found in infectious meningo-encephalitis, in vascular diseases of the central nervous system, and, unexpectedly, in several cases of dementia without obvious vascular pathology.

Bacterial Infections↗

Automated particle-counting immunoassay for alpha-fetoprotein.

PACIA, a homogeneous non-radioimmunoassay, has been adapted to the determination of serum alpha 1-fetoprotein. This technique is based on the agglutination of latex particles coated with antibodies to the antigen to be determined. The agglutination is measured by using an optical cell counter designed to count blood cells, to determine the reduction in the number of non-agglutinated particles. Interferences by serum constituents are avoided by coating the particles with the F(ab')2-fragments of th immunoglobulin G fraction of the antiserum. The system is automated, with a sampling rate of 50/h and an incubation time of 26 min. Concentrations used in preparing the standard curve ranged from 1 to 50 microgram/L; analytical recoveries were 93.5 to 98.4%; the correlation coefficient of PACIA with radioimmunoassay, calculated from results on 127 samples, was 0.98; maximum within- and between-assay CVs were 7.4% and 9.6%, respectively.

Agglutination Tests↗

Automated particle-counting immunoassay for digoxin.

We describe a non-radioisotopic automated immunoassay for serum digoxin in the therapeutic range at 50 samples per hour by use of the particle-counting immunoassay technique and a special reagent, rheumatoid factor. Digoxin is determined by evaluating its inhibitory activity on the agglutination of digoxin-coated latex particles. The agglutinating system consists of the anti-digoxin IgG mixed with rheumatoid factor. This anti-IgG autoantibody reacts with IgG when they are aggregated or bound to a surface. Interference by serum proteins was prevented by pepsin digestion at 37 degrees C. Correlation with radioimmunoassay was r = 0.94 for 109 samples with concentrations between 0 and 5.7 micrograms/L. Analytical recovery overall averaged 102%. Within-assay precision (CV) ranged from 12.5% at 0.96 micrograms/L to 4.4% at 2.97 micrograms/L; between-assay precision varied from 8.4% at 0.75 micrograms/L to 5.8% at 2.92 micrograms/L.

Antigen-Antibody Complex↗