| Autor: |
Lentjes EG; Department of Clinical Chemistry, University Hospital Leiden, The Netherlands., Romijn F, Maassen RJ, de Graaf L, Gautier P, Moolenaar AJ |
| Jazyk: |
angličtina |
| Zdroj: |
Clinical chemistry [Clin Chem] 1993 Dec; Vol. 39 (12), pp. 2518-21. |
| Abstrakt: |
A method is described for a temperature-controlled ultrafiltration procedure to measure free cortisol in serum. A special thermometer with a sensor was developed, measuring the temperature directly in the ultrafiltration device. The sensor is screwed on the axis of the centrifuge rotor, and the centrifuge is placed in a temperature-controlled box so that the temperature of the sample is kept at 37 degrees C +/- 0.1 degrees C. The overall CV of the free cortisol assay ranges from 2.2% to 11.4%, of which the ultrafiltration contributes only 2.2-3.6%. Increasing amounts of cortisol-binding protein, as found in women using estrogen-containing oral contraceptives, have minor but significant effects on the free cortisol concentrations in serum. Serum free cortisol concentrations in a reference population (n = 114; central 95 percentiles) were 12-43 nmol/L (4-9.5% of total cortisol); in the group of the oral-contraceptive users (n = 27), the reference interval was 11-53 nmol/L (1.5-4.5%). |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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