The determination of thyroxine and thyroxine uptake with new homogeneous enzyme immunoassays using Boehringer Mannheim/Hitachi analysis systems.

New homogeneous enzyme immunoassays for the determination of thyroxine and thyroxine uptake have been developed. The CEDIA assays are based on the cloned enzyme donor immunoassay technology, which involves fragments of beta-galactosidase prepared by genetic engineering. The assays have been adapted for Boehringer Mannheim/Hitachi analysers. The CEDIA T4/T Uptake assays were evaluated in eleven clinical chemistry laboratories on various Boehringer Mannheim/Hitachi analysis systems, using a 2-point calibration. The analytical range of the T4 test was 10 to 258 nmol/l thyroxine. The T uptake test had a measuring range between 20-50%. Depending on the concentration of the analyte (samples from hypo-, eu- or hyperthyroid patients), mean coefficients of variation ranged from 1.8 to 4.8% within-run and from 4.1 to 6.5% between-run for the T4 assay. Even better coefficients of variation were obtained for the T uptake assay (1.4 to 2.3% within-run, 2.8 to 3.3% between run). The relative inaccuracy of the CEDIA assays with respect to values assigned by other tests was satisfactory in various control sera. The T4 assay was compared with one radioimmunoassay, one enzyme immunoassay and one fluorescence polarisation immunoassay. Slopes ranging from 0.9 to 1.1 and intercepts ranging from -10 to +10 nmol/l thyroxine were obtained with two exceptions. The results of the T uptake test correlated reasonably with those of other thyroxine-binding methods. No interference was observed with icteric and lipaemic sera. Haemoglobin up to 4 g/l had no significant influence. Results of the CEDIA T Uptake test are mainly used for calculation of the free thyroxine index, in which the thyroxine value is corrected for variations of thyroxine-binding protein concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)

[Hepatic protein synthesis of the kallikrein-kininogen-kinin system]. / Synthèse protéique hépatique du système kallikréine-kininogènes-kinines.

Plasma prekallikrein and kininogens were assayed by specific enzymatic and immunological methods in cirrhotic patients with terminal liver failure and during oestrogenic impregnation. In cirrhotic patients plasma levels of these substances were significantly lowered and they correlated negatively with necrosis enzymes. A highly significant positive correlation was found between coagulation factor values and the levels of prekallikrein and kininogens. During oestrogenic impregnation the levels of the constituents of the kallikrein-kinin system were significantly increased when compared with reference values. These findings indicate that plasma concentrations of prekallikrein and kininogens are dependent upon liver synthesis capacity.

Plasma prokallikrein and kininogens in burned patients.

Using specific immunological (1) and enzymatic (2) methods, we have measured prokallikrein, total, high, and low molecular weight kininogens in 36 severely burned patients. At admission to the intensive care unit, all constituents were significantly decreased when compared to previously defined reference intervals. The values remained low during the three first days after burn. The changes affecting total and low molecular weight kininogens were significantly correlated (p less than 0.05) with the severity of the burn area. Prokallikrein and kininogens levels were also closely related to the concentrations of C3c and C4 complement factors.

The influence of haemodialysis and haemofiltration on the clearance of torasemide in renal failure.

The concentration of Torasemide in plasma, dialysate and ultrafiltrate were determined during one haemofiltration and three dialyses. Results show that Torasemide is not significantly eliminated from the blood by these technics.

[Physiopathologic significance of the radioimmunologic determination of human kininogens]. / Signification physiopathologique des dosages radioimunologiques des kininogènes humains.

We quantify total and high molecular weight kininogens by radioimmunoassay. The main characteristic of these molecules is the release of kinins. In this paper we would compare the antigenicity of kininogens with their pharmacological property.

Analytical evaluation of a new latex agglutination test for quantitative determination of C-reactive protein by laser nephelometry.

A new reagent for the rapid and reliable quantitative determination of C-reactive protein (CRP), using polystyrene particles coated with antibodies against CRP, is now available. We present an analytical evaluation of this new test system. The analytical characteristics of sensitivity, linearity, precision and specificity are excellent. Samples from patients with various inflammatory conditions were tested. Correlation between the examined technique and current methods such as radial immunodiffusion, classical laser nephelometry and enzyme immunoassay were excellent.

Optimized determination of plasma prokallikrein on a Hitachi 705 analyser.

Manual determination of plasma prokallikrein using a chromogenic substrate is tedious. We describe the optimal conditions of enzymatic quantification by a fully automated method enabling rapid availability of the results and an easier estimation of this interesting compound in clinical chemistry.

[Role of the kallikrein-kininogen-kinin system in the inflammatory reaction and septic shock]. / Rôle du système kallikréines-kininogènes-kinines dans la réaction inflammatoire et le choc septique.

Kinins, which are vasodilatory, permeability-increasing, pain-producing polypeptides, are formed from inactive precursors: kininogens. Their actions make kinins a particularly powerful potential pro-inflammatory factor. However the absence of specific antagonists has so far made it impossible to ascribe them a definite role in inflammation. Two studies of experimental endotoxemia in burns patients, septicemia and septic shock have demonstrated the following facts: activation occurs of specific ( pKK ) and non-specific (plasminogen-plasmin system) kininogenases , K-HMW and K-LMW levels are significantly decreased. Kininogen consumption corresponds to increased BDK production. This would therefore appear to be one of the humoral factors responsible for haemodynamic changes. Though measurement of kininogen levels is still a painstaking process, the development of chromogenic substrates has made pKK and KK measurement simple and fast. Once they have been validated physico-pathologically in a large number of patients, such assays should take their place among the diagnostic weapons of clinical biology at the disposal of clinicians.