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Biomedical subjects

D J Cox

Publications and source records attributed to D J Cox.

At least 127 records · Page 7Linked to original sources

Isolation and characterization of trypsin inhibitor from opaque-2 corn seeds.

Trypsin inhibitor was isolated from seeds of opaque-2 corn by affinity chromatography on a trypsin/Sepharose column. The two major forms of inhibitor eluted from the affinity column were separated by DEAE-cellulose chromatography in the presence of urea. One form of inhibitor is a single-chain protein that has a molecular weight of approximately 12,500; the second inhibitor has two polypeptide chains and appears to have been produced from the single-chain inhibitor by exposure to trypsin in the affinity chromatography step. The relationship of the inhibitor isolated from opaque-2 corn to an inhibitor previously isolated from an unspecified strain of maize by Hochstrasser et al. (Hochstrasser, K., Muss, M., and Werle, E. (1967) Z. Physiol. Chem. 348, 1337-1340) is discussed.

Chromatography, Affinity↗

The origin of experimental brain tumours: a sequential study.

A sequential study of rat brains treated transplacetally with the neurotropic carcinogen ethylnitrosourea reveals small foci of cell proliferations from the age of 8 weeks. These lesions consist mainly of undifferentiated cells of the subependymal plate type. They occur in those areas in which gliomas develop and represent the earliest, histologically detectable, changes in the development of brain tumours.

Animals↗

The fine structure of blood vessels in ethylnitrosourea-induced tumours of the rat nervous system: with special reference to the breakdown of the blood-brain barrier.

The fine structure of capillaries in and around ethylnitrosourea-induced tumours, gliomas and schwannomas, was examined in rats. A great variation was observed in the severity of changes: the degree of abnormality depended on the histological type and size of the tumour and on the site of the capillaries within the neoplasm. Endothelial cells, basement membranes and pericytes all demonstrated changes in their fine structure. The most striking alterations occurred in the endothelial cells: luminal cell membranes, tight junctions and pinocytotic activity were all modified. The widened extracellular spaces, particularly around capillaries, were frequently seen to contain proteinaceous material and haematogenous cells. Invasion of these spaces by neoplastic cells, however, rarely occurred. Formation of new capillaries was indicated by the mitotic activity of endothelial cells. These changes in the blood vessels of cerebral tumours have an important role in the breakdown of the blood-brain barrier.

Animals↗