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)

Comparison of blood glucose profile and glycemic control in type 1 diabetic patients treated with Actrapid-Monotard or Actrapid Protaphane (NPH) human insulins.

The aim of this study is to compare the blood glucose profile and the glycemic control in Type 1 diabetic patients under two conventional semi-synthetic human insulin regimens (2 daily injections) combining regular (Actrapid) and intermediate acting insulins (Monotard or Protaphane). Actrapid-Monotard (scheme A) and Actrapid-Protaphane (scheme B) were administered during 3 months each, in a randomized order, to 18 outpatients. The glycemic control was evaluated by home glucose monitoring, as well as by the monthly measurements of HbA1. The total daily dose of insulin was comparable during each treatment period: 0.68 +/- 0.06 (scheme A) and 0.71 +/- 0.06 U/kg body wt. (scheme B) (mean +/- SEM). However, the total percentage of regular insulin was higher with Monotard than with Protaphane: 58 +/- 3 vs 48 +/- 5% in the morning (p less than 0.005) and 51 +/- 2 vs 46 +/- 3% in the evening (p less than 0.05). In C-peptide positive patients, the blood glucose values were comparable at all times with either insulin scheme. In contrast, in C-peptide negative patients, the blood glucose levels were higher in the afternoon with scheme B: 11.8 +/- 1 vs 8.6 +/- 1 mmol/l at 3 pm (p less than 0.02) and 12.2 +/- 1.3 vs 9.7 +/- 1.6 mmol/l at 6 pm (p less than 0.01). A slight but not significative increase of HbA1 was observed during the B period. In conclusion, an Actrapid-Protaphane scheme requires the use of a lower proportion of regular insulin than an Actrapid-Monotard treatment.(ABSTRACT TRUNCATED AT 250 WORDS)