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C L de Ligny

Publications and source records attributed to C L de Ligny.

28 records · Page 2Linked to original sources
PubMed1982

The influence of the method of preparation of the bone scanning agent 99mTc(Sn)EHDP on its tissue distribution in the rat.

The tissue distribution in the rat of the bone scanning agent 99mTc(Sn)EHDP is investigated by three methods, viz. by dissecting the animals 3 and 24 h post injection, by scanning the animals with a rectilinear scanner and by whole body autoradiography, particular of micro-sections of the skeleton. The effect of varying the experimental conditions in the preparation of the bone scanning agent (pH and concentrations of Sn(II) and EHDP) is investigated. In some of the experiments additional amounts of Sn(II) and EHDP are added to the reaction mixture after the preparation of the bone scanning agent. In this way the influence of the Sn(II) and EHDP concentrations on the composition of the bone scanning agent, and their influence as such on tissue uptake can be separately investigated. The 99mTc-uptake in bone is compared with the distribution of the 99mTc over the two main products in the reaction mixture, viz. 99mTc(IV)-Sn-EHDP2 and 99mTc(IV)-Sn-EHDP. In addition, the stability in vitro of some of the preparations in urine and plasma and the in vivo binding of the 99mTc to plasma proteins are determined. A procedure for the preparation of the bone scanning agent is recommended.

Animals↗
PubMed1978

Experimental optimization of the detection limit of one-step solid-phase radioimmunoassay.

The minimal detection limit and the conditions of maximal sensitivity of a one-step solid-phase inhibition radioimmunoassay for human immunoglobulin A have been determined by application of statistical methods of experimental optimization. The choice of the optimal combination of qualitative variables, such as the origin of the antibody and the nature of the solid phase, was made by the study of a covariable under non-optimal conditions of the quantitative variables, such as the amount of antibody. The covariable was the avidity of the antibody, which is expected to have a large influence on the sensitivity. Only the difference in avidity between two immunosorbents with cellulose or Sepharose as solid-phase material proved to be statistically significant, and further study was done with cellulose. The experimental optimization of the sensitivity as a function of five quantitative variables yielded a reduction of the detection limit by a factor 5.6 (from 23.5 to 4.2 ng IgA). The variables determining the amount of insolubilized antibody in the assay had the largest influence on the value of the detection limit. The conditions of optimal sensitivity did agree with the predictions by a physical model of radioimmunoassay. The results are discussed in relation to the assay parameters such as the amount and the avidity of the insolubilized antibody and the initial percentage of binding, and in relation with theoretical optimization of the sensitivity.

Animals↗
PubMed1978

Experimental optimization of the detection limit of two-step solid-phase radioimmunoassay.

For two-step inhibition radioimmunoassay (sequential saturation or delayed addition of labeled antigen) generally a higher sensitivity than for one-step inhibition radioimmunoassay (equilibrium assay) is expected. The detection limit of a two-step solid phase inhibition radioimmunoassay for human serum immunoglobulin A was minimized by statistical methods of experimental optimization. Under optimal conditions the detection limit was 2.3 ng IgA. This is about 1.8 times lower than the minimal detection limit of the one-step assay under similar conditions of the qualitative variables such as the origin of the antibody. This increase in sensitivity was associated with a decrease in the precision of the assay. The results are discussed with respect to the comparison of the one-step and the two-step assay and the usefulness of a sensitive radioimmunoassay in practice.

Evaluation Studies as Topic↗