1. The N-(2-hydroxyethyl)alanine esterified to phosphatidic acid in anaerobic ciliate rumen protozoa has the l configuration. 2. Labelling experiments with Entodinium caudatum cultures using [(32)P]P(i) [2-(14)C]ethanolamine and (32)P- and (14)C-labelled phosphatidylethanolamine show that phosphatidylethanolamine is the direct lipid precursor of the N-(2-hydroxyethyl)alanine-containing phosphol...

The human erythrocyte membrane skeleton consists of a network of short actin filaments cross-linked into a hexagonal network by long, flexible spectrin molecules. The lengths of the short actin filaments (33 +/- 5 nm) at the central junctions are proposed to be stabilized and limited by association with tropomyosin and the tropomyosin-binding protein, tropomodulin. Here, we use immunogold label...

AIM To compare the Ki-67 labelling index determined using the enhanced peroxidase one step (EPOS) method with that using the standard ABC technique in pituitary tumours. METHODS Adjacent sections were immunostained using the EPOS and ABC techniques with the same Ki-67 antibody and same antigen retrieval method. RESULTS The labelling index measurements with the EPOS Ki-67 antibody were signi...

Much indirect evidence supports the assumption that tritiated thymidine does not label cells which enter the deoxyribonucleic acid synthesis phase (S) more than 1 h after injection. Direct evidence confirming this assumption was obtained by counting labelled epithelial nuclei in mice killed i, 4 or 6 h after a single intraperitoneal injection of [H]thymidine; colchicine was used to prevent the ...