[Precision and accuracy of the measurement of total cholesterol using the reflectometer Accutrend GC. Usefulness in primary care for diagnosis of hypercholesterolemia]. / Precisión y exactitud de la medida del colesterol total mediante el reflectómetro Accutrend GC. Aplicabilidad en atención primaria para la detección de hipercolesterolemias.

OBJECTIVES: To determine the accuracy and precision of the Accutrend GC (AGC) in measuring cholesterol totals (CT) and its use as a screening test to detect hypercholesterolaemia. DESIGN AND PARTICIPANTS: Venous blood was drawn from 104 patients to measure CT by an enzymatic method (Hitachi 717). At the same time, their capillary blood was also measured with the AGC on two consecutive occasions. Values were divided in three groupings: CT > 149 mg/dl and < or = 199 mg/dl (n = 27); CT > 199 mg/dl and < or = 249 mg/dl (n = 59); and CT > or = 250 mg/dl (n = 18). Accuracy was calculated by obtaining the mean differences (MD) and the confidence intervals of the values obtained with the AGC in the three groupings and comparing them with the values obtained by the laboratory method. Precision was assessed by correlation, the comparison of paired means and the mean coefficient of variation of the values obtained with the AGC in the two successive measurements. MAIN MEASUREMENTS AND FINDINGS: In each grouping the MD of the values obtained with the AGC were lower than those obtained by the laboratory method, respectively. CONCLUSIONS: The AGC is useful as a screening test to detect hypercholesterolaemia, because of its high accuracy and precision. As it also determines glucose it is very useful for diabetics.

Simple radioimmunological method for urinary 6-keto-PGF1 alpha measurement.

A radioimmunoassay for the determination of 6-keto-PGF1 alpha (stable metabolite of Prostacyclin) in urine using a specific antiserum, is described. The antibody used, showed no significant cross-reactivity with other PGS. (3H)-6-keto-PGF1 alpha has been used as tracer and a 30% Hydroxyapatite suspension was utilized for the separation of bound and free fractions. Standard curve ranges between 2 and 1000 pg thus allowing measurements in urine. Aliquots of 0.2 to 1 ml of 24 hours urinary samples were submitted to a preextraction step with Hexane in order to eliminate neutral fats. After acidifying with 0.1 N HCl to pH = 3.5-4, an Ethyl Ether extraction step was performed showing a recovery of 66%. Repeated analysis of a rat urine pool, showed 7.7 intraassay and 9.8 interassay variation coefficients. Values obtained amounted to 38.3 +/- 4.6 ng/24 h in normal rats and 133 +/- 32 ng/24 h in 5% NaCl loaded rats (p less than 0.001). The values obtained in healthy men were 508 +/- 94 ng/24 h and in women 375 +/- 136 (p less than 0.05).