Factor XI deficiency and a platelet defect.

A patient with a lifelong bleeding tendency of moderate severity was found to have both factor XI deficiency and a long bleeding time. There was a significant deficiency of platelet factor 3, but other parameters of platelet function were normal. Infusion studies showed that both fresh plasma and platelet concentrate were required for complete correction of the haemostatic abnormalities, suggesting that these two defects were inherited coincidentally.

Plasma vitamin K1 in mothers and their newborn babies.

Plasma vitamin K1 (phylloquinone) was assayed in normal adults and pregnant women at term and their babies by a method based on high-performance liquid chromatography. The mean plasma concentration in 30 healthy, fasting adults was 0.26 ng/ml (range 0.

The content of phylloquinone (vitamin K1) in human milk, cows' milk and infant formula foods determined by high-performance liquid chromatography.

Phylloquinone (2-methyl-3-phytyl-1,4-naphthoquinone) in human and cows' milk and in infant formula foods has been assayed by a method based on high-performance liquid chromatography (HPLC). The method has three chromatographic steps consisting of a preliminary purification of lipid extracts by conventional liquid chromatography, a further fractionation by semipreparative HPLC and a final analytical step by reversed-phase HPLC in which phylloquinone was resolved from the remaining contaminants and quantified by reference to an internal standard (phylloquinone 2,3-epoxide). The identity of the chromatographic peak ascribed to phylloquinone (vitamin K1) was established by mass spectrometry.