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Biomedical subjects

J A Weatherell

Publications and source records attributed to J A Weatherell.

11 recordsLinked to original sources

Matrix and mineral changes in developing enamel.

An investigation of the changes taking place in the enamel and the enamel organ during enamel development has been carried out by analyzing small samples of tissue dissected from developing incisors of rat and bovine incisors. Observations showed that the synthesis of the enamel matrix and its subsequent loss were associated chiefly with a change in the major matrix components. This consisted of a selective loss of amelogenin components prior to secondary mineralization. Before this loss, some increase in the proportion of smaller molecular weight components suggested the possibility of limited breakdown. Even at the earliest stages examined, significant concentration of mineral ions was present. This increased steeply after most of the organic matrix had been removed. The Ca/P ratio of this mineral was constant throughout development. The concentration of minor inorganic ions (F, Mg and CO3) decreased as the tissue developed and a tendency was observed for certain ions (F, 32PO4) to penetrate and concentrate in the enamel, apparently as a consequence of the lost matrix being replaced by water, just prior to the steep increase in mineral content of the tissue.

Amelogenesis

Changes in amino-acid composition of developing rat incisor enamel.

The amino-acid composition and total "protein" content of enamel particles dissected serially from the developing enamel of rat incisors have been determined. Changes in protein content and amino-acid composition occurred throughout all stages of development. The most obvious alterations occurred in the vicinity of a white opaque band. Here, protein was lost most rapidly and considerable changes in amino-acid composition occurred.

Amino Acids

Arrest and control of carious lesions: a study based on preliminary experiments with resorcinol-formaldehyde resin.

An experimental investigation has been made into the possibilities of retarding the progress of carious attack by infiltrating cariostatic material into enamel lesions. The problems associated with this kind of procedure are discussed against the background of experimental observations made using a formulation based on a resorcinol-formaldehyde resin.

Animals