Short-term variations in enterolactone in serum, 24-hour urine, and spot urine and relationship with enterolactone concentrations.

iron concentration or UIBC value is below detectable limits, TIBC cannot be determined. In conclusion, TIBC values determined by DTIBC assay were strongly correlated with TRF concentrations. The slope of the regression line for the DTIBC values plotted against the TRF is consistent with the theoretical TIBC/ TRF ratio. TIBC values calculated from the sum of serum iron and UIBC were significantly lower than those obtained by the DTIBC assay. This can be attributed to underestimation of UIBC values by the colorimetric assay. UIBC is an independent factor that influences the difference between the converted TIBC values and the calculated TIBC values. We suggest that TIBC be measured by direct TIBC methods and that UIBC be calculated as the difference between TIBC and serum iron. relationship between chemically measured total iron-binding capacity concentrations and immunologically measured transferrin concentrations in human serum. Development of a fully automated TIBC method for the Dimension ® clinical chemistry system [Abstract]. Clin Chem 2000; 46:A146. Direct serum total iron-binding capacity assay suitable for automated analyzers. Hereditary ceruloplasmin deficiency with hemosiderosis: a clinicopatholog-ical study of a Japanese family. Enterolactone, a mammalian lignan, is produced by co-lonic microflora from precursors present in food plants. Because intake of vegetables, fruits, berries, or whole grains is related to the enterolactone concentration in blood (1, 2) and excretion in urine (3, 4), enterolactone may function as a biomarker of fiber-rich foods. Important characteristics for a biomarker include convenient, low-risk collection of samples; specific, reliable laboratory measurement; and a high ratio of between-person to total variability [intraclass correlation (ICC)] (5). In epidemio-logic studies, analytes with a low ICC often show weak associations with any disease (6). The present study describes the short-term variation in enterolactone in serum, 24-h urine, and spot-urine en-terolactone:creatinine ratio and the relationship between enterolactone concentrations in serum, 24-h urine, and spot urine. The study protocol was approved by the Ethics Committee on Epidemiology and Public Health in the hospital district of Helsinki and Uusimaa. Twenty volunteers (13 females and 7 males) were recruited among university students. Exclusion criteria included age Ͻ18 years, anti-bacterial treatment during the preceding 3 months, and any major illness or regular medication, except contraceptive pills. The average age of the participants was 22.2 years [95% confidence interval (CI), 21.4 –22.9 years], and the average body mass index was 22.3 (20.9 –23.6) kg/m 2. Of the female participants, seven took oral contraceptives. The female …