[Improving the interlaboratory variation for creatinine serum assay].

Purpose: To assess inter-assay variation and accuracy of blood creatinine measurements as well as the effect of the standardization of the calibration procedures on inter-assay variation.

Methods: Inter-assay variation and accuracy were assessed using 30 frozen human sera and 3 certified reference materials, which were analysed by 17 creatinine assays (colorimetric: 12, enzymatic: 4, HPLC: 1). Usual calibration procedure was compared with two common calibration procedures using either a reference material (404.

[Comparison of methods for the determination of blood creatinine].

Creatinine is the criterion the most widely used for kidney exploration, either directly or through algorithms. Up to now, it appears that methods of creatinine determination are still very heterogenous. The aim of the present study was to compare the different available methods and to evaluate their impact on the formula of predicted clearance.

Thyroid testing using the Cobas Core immunoassay system. A multicentre study.

The random access immunoanalyzer Cobas Core and the Cobas Core Thyroid Assays were assessed as to their clinical usefulness in the analysis of different thyroid diseases. Four centres participated in this study measuring the following five thyroid tests per sample on the instrument: thyrotropin, free thyroxine, thyroxine, triiodothyronine and free triiodothyronine. The assessment was based on studies of precision and clinical samples.

[Comparative study of lipids, apoproteins and lipoproteins in patients with coronary disease and in a control population].

We carried out a comparative study of various lipid parameters (apo AI and B, LpAI, Lp(a) and LpBCIII) in coronary heart disease patients (19 males and 4 females, mean age 61 +/- 11 years) and in controls (18 males and 14 females, mean age 55 +/- 3 years) selected so that cholesterol and triglycerides levels be beneath 6 and 2.3 mmol/l in both populations. Apo AI and B were analysed by immunonephelometry and lipoparticles by electroimmunodiffusion.