Nutrient-induced activation of trehalase in nutrient-starved cells of the yeast Saccharomyces cerevisiae: cAMP is not involved as second messenger.

Starvation of Saccharomyces cerevisiae cells for specific nutrients such as nitrogen, phosphate or sulphate causes arrest in the G1 phase of the cell cycle at a specific point called 'start'. Re-addition of different nitrogen sources, phosphate or sulphate to such starved cells causes activation of trehalase within a few minutes. Nitrogen-source- and sulphate-induced activation of trehalase were not associated with any change in the cAMP level, but in the case of phosphate there was a small transient increase.

Pyruvate kinase: diagnostic value in neuromuscular disease.

Pyruvate kinase activity was examined in the sera of a group of patients with neuromuscular disease and in carriers, and compared with that of creatine kinase. The following observations were made: 1. Pyruvate kinase activity was elevated in all 14 patients with Duchenne muscular dystrophy, with very high values generally correlating inversely with age or disease duration.