Biomaterial Database

Evaluation of a radioimmunoassay of urinary cortisol without extraction. 1989

C M Huang, and M Zweig

Clinical Pathology Department, Warren Grant Magnuson Clinical Center, Bethesda, MD 20892.

We evaluated the Kallestad "Quanticoat" cortisol RIA for direct (no extraction) measurement of urinary free cortisol, which requires no solvent extraction. An analytical-recovery study showed a linear regression of y (measured) = 0.65x (added) + 37.5 micrograms/L (Sy.x = 21.4 micrograms/L, r = 0.978, n = 48). Recovery appeared to vary with the urine used and with the concentrations of cortisol added. Within- and between-run CVs were less than or equal to 4.1% and less than or equal to 3.8%, respectively. Cross reactivities were low, except for prednisolone (20.5%). This no-extraction method gave higher values for urinary free cortisol than did either an RIA method involving extraction or an HPLC method. A comparison study with the HPLC (x) and with the method involving extraction (x') gave the following Deming-debiased regression equations: y = 1.60x + 68.8 (Sy.x = 34.4, n = 29) and y = 1.33x' + 0.69 (Sy.x = 40.3, n = 66), respectively. We conclude that the no-extraction method may give misleading results for patients' diagnosis or management if this cross reactivity is not taken into account.

UI	MeSH Term	Description	Entries
D011239	Prednisolone	A glucocorticoid with the general properties of the corticosteroids. It is the drug of choice for all conditions in which routine systemic corticosteroid therapy is indicated, except adrenal deficiency states.	Di-Adreson-F,Predate,Predonine,Di Adreson F,DiAdresonF
D011786	Quality Control	A system for verifying and maintaining a desired level of quality in a product or process by careful planning, use of proper equipment, continued inspection, and corrective action as required. (Random House Unabridged Dictionary, 2d ed)	Control, Quality,Controls, Quality,Quality Controls
D011863	Radioimmunoassay	Classic quantitative assay for detection of antigen-antibody reactions using a radioactively labeled substance (radioligand) either directly or indirectly to measure the binding of the unlabeled substance to a specific antibody or other receptor system. Non-immunogenic substances (e.g., haptens) can be measured if coupled to larger carrier proteins (e.g., bovine gamma-globulin or human serum albumin) capable of inducing antibody formation.	Radioimmunoassays
D011933	Reagent Kits, Diagnostic	Commercially prepared reagent sets, with accessory devices, containing all of the major components and literature necessary to perform one or more designated diagnostic tests or procedures. They may be for laboratory or personal use.	Diagnostic Reagent Kits,Diagnostic Reagents and Test Kits,Diagnostic Test Kits,In Vitro Diagnostic Device,In Vitro Diagnostic Devices,In Vitro Diagnostic Medical Device,In Vitro Diagnostic Medical Devices,Kits, Diagnostic Reagent,Diagnostic Reagent Kit,Diagnostic Test Kit,Kit, Diagnostic Reagent,Kit, Diagnostic Test,Kits, Diagnostic Test,Reagent Kit, Diagnostic,Test Kit, Diagnostic,Test Kits, Diagnostic
D012044	Regression Analysis	Procedures for finding the mathematical function which best describes the relationship between a dependent variable and one or more independent variables. In linear regression (see LINEAR MODELS) the relationship is constrained to be a straight line and LEAST-SQUARES ANALYSIS is used to determine the best fit. In logistic regression (see LOGISTIC MODELS) the dependent variable is qualitative rather than continuously variable and LIKELIHOOD FUNCTIONS are used to find the best relationship. In multiple regression, the dependent variable is considered to depend on more than a single independent variable.	Regression Diagnostics,Statistical Regression,Analysis, Regression,Analyses, Regression,Diagnostics, Regression,Regression Analyses,Regression, Statistical,Regressions, Statistical,Statistical Regressions
D002851	Chromatography, High Pressure Liquid	Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.	Chromatography, High Performance Liquid,Chromatography, High Speed Liquid,Chromatography, Liquid, High Pressure,HPLC,High Performance Liquid Chromatography,High-Performance Liquid Chromatography,UPLC,Ultra Performance Liquid Chromatography,Chromatography, High-Performance Liquid,High-Performance Liquid Chromatographies,Liquid Chromatography, High-Performance
D003350	Cortodoxone	17,21-Dihydroxypregn-4-ene-3,20-dione. A 17-hydroxycorticosteroid with glucocorticoid and anti-inflammatory activities.	11-Deoxycortisol,11-Desoxycortisone,Cortexolone,11-Desoxycortisol,Reichstein's Substance S,11 Deoxycortisol,11 Desoxycortisol,11 Desoxycortisone,Reichstein Substance S,Reichsteins Substance S,Substance S, Reichstein's
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D006854	Hydrocortisone	The main glucocorticoid secreted by the ADRENAL CORTEX. Its synthetic counterpart is used, either as an injection or topically, in the treatment of inflammation, allergy, collagen diseases, asthma, adrenocortical deficiency, shock, and some neoplastic conditions.	Cortef,Cortisol,Pregn-4-ene-3,20-dione, 11,17,21-trihydroxy-, (11beta)-,11-Epicortisol,Cortifair,Cortril,Epicortisol,Hydrocortisone, (11 alpha)-Isomer,Hydrocortisone, (9 beta,10 alpha,11 alpha)-Isomer,11 Epicortisol