Stoichiometric dye-binding procedure for the determination of the reactive lysine content of soya bean protein

A new analytical method has been developed for the determination of the reactive lysine content of soya bean protein. The method is based on the reaction of the free basic groups of the protein with 1-phenylazo-2 naphthol-6,8 disulphonic acid. With regard to the stoichiometry of the procedure, it has been proved, contrary to earlier reports, that the basic amino acids, histidine, arginine and lysine, each combine with one mole of the dye. After acylation with propionic anhydride lysine alone loses its dye reactivity. The usefulness of the proposed method has been demonstrated by the determination of the reactive lysine content of several untreated, heat-treated and acid-treated soya bean samples. The results show that heat damage of about 5% in reactive lysine content can be measured in 1·5 h with good reproducibility.     

Adenoid cystic carcinoma of the lacrimal gland in a six-year-old girl

A 6-year-old white female was found to have an adenoid cystic carcinoma originating in a lacrimal gland. Eighteen months following diagnosis, the tumor recurred. Conservative surgery has been the sole mode of therapy. To date, after four operations and quadrimenstral imaging surveillance, there is no sign of disease progression. Our purpose is to record the unusual occurrence of an adenoid cystic carcinoma of the lacrimal gland in a child. An interim report, 32 months after diagnosis, is presented.     

Balance-dendrogram. A new routine of CoDaPack

A statistical analysis of compositional data based on the Aitchison geometry of the simplex requires an appropriate basis for representing the data. A simple and intuitive way of building such a basis employs a sequential binary partition of the compositional vector. The partition, together with some statistical summaries of the coordinates, or balances, can be represented in a dendrogram-type graph. In this paper we introduce an implementation of this methodology inside CoDaPack, which is freeware. An example with real data illustrates the use of the Balance-Dendrogram routine.