[A study of the determination of serum fucose concentrations].

We examined the biochemical properties of reaction products during the procedure for serum fucose determination (Dische & Shettles). The optical density at 396 nm (OD396) of the reaction products increased linearly with the increment of fucose concentrations, and was stable for at least 210-240 min at room temperature. The reaction products were destroyed with the addition of distilled water. Sephadex G-200 gel chromatography of the mixed serum samples revealed a single peak of fucose in the void volume fractions. Of interest was the presence of trace amounts of fucose detected in the low-molecular weight fractions less than 66,000, suggesting the presence of free fucose in the serum. Based on these observations, the method for serum fucose determination was modified so it was possible to use 100 microliters of the serum sample. The mean serum fucose concentration, measured by this modified method, was 561.0 +/- 191.1 mumol/l (9.1 +/- 3.1 mg/dl) in normal healthy children. In patients with idiopathic nephrotic syndrome, the values were significantly higher both at relapse and in remission than those in normal healthy children.