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Biomedical subjects

G Doyen

Publications and source records attributed to G Doyen.

14 recordsLinked to original sources
PubMed1983

An improved method for isolation of specific antibodies by affinity chromatography; application to an antiserum to testosterone.

The specificity of polyclonal antibodies for use in immunoassay procedures can be improved by purification on affinity columns. The standard procedure involves immunoabsorption of the specific antibody populations on the insolubilized antigen, followed by desorption from the latter. However, the desorption process usually results in antibody damage and loss of antibody titer. We therefore designed an affinity chromatography procedure involving immunoabsorption of the main cross-reacting antibody fractions instead of the specific ones, eliminating thereby the desorption step. We exemplify the procedure with the purification of an anti-testosterone antibody.

Animals↗
PubMed1983

Further evidence for distinction between sex hormone-binding globulin and an androgen-binding protein in hydatidiform mole serum.

We further studied the androgen-binding protein (ABP) that we recently evidenced in the serum from two patients with hydatidiform mole [Ref. 4]. This protein was further shown to be distinct from the sex hormone-binding globulin (SHBG) by concanavalin A and ion-exchange chromatographies, as well as spectrophotometric and kinetic studies. However, the ABP was shown to have a molecular weight and relative affinities for several steroids, similar to those of SHBG. Our results lead us to suppose that the ABP previously evidenced in molar vesicles and fluid [Ref. 5] is secreted in the serum. It is, however, likely that the secretion process alters the binding affinity of this protein. The presence of this additional binding component in the serum of patients with such trophoblastic tumours, may reduce severely the free 17 beta-hydroxyandrogens levels, as well as may help create a release gradient in the serum steroids buffer stores.

Androgen-Binding Protein↗
PubMed1982

Measurement of placental lactogen in undiluted serum by radioimmunoassay utilizing polyethylene glycol as separating agent. Values obtained in pregnancy.

We describe a simple and reliable radioimmunoassay (RIA) method for the measurement of human placental lactogen (hPL) in undiluted serum. Standard curves, in serum, cover the range of 0.015 to 1 mlU/L for early pregnancy monitoring (7 to 15 weeks, referred to as Procedure I), and 0.531 to 17 mIU/L for mid and late pregnancy monitoring (16 to 40 weeks, referred to as Procedure II). In a typical assay, 0.05 mL of serum are incubated with constant amounts of antiserum and 125I-hPL for 1 hour (in Procedure I), or 30 minutes (in Procedure II). At the end of the incubation, a 260g/L polyethylene glycol solution is added, in order to bring the polymer concentration in the assay tube to 130g/L. The tube contents are mixed and centrifuged. The supernatant is removed and the precipitate counted. The antiserum dilution for both procedures was chosen after classical titration without and with addition of 0.531 mIU/L of unlabelled hPL; the titration was performed with the desired incubation time of 30 minutes. This technique showed a good correlation with a solid phase second antibody RIA (r = 0,95; n = 215).

Female↗