In previous papers (1,2) evidence was presented to show that condensed fish solubles produced a marked increase in the growth rate of chicks on diets containing an adequate level of vitamins and essential amino acids. Berry, Carrick, Roberts, and Hauge (3) found that a water extract of fish solubles was also active in stimulating the growth of chicks. Very little other information on the proper...

1. The effect of a protein-free meal and a protein-rich meal on the concentration of free amino acids in plasma and muscle tissue was studied in eight healthy subjects. The energy content of the protein-free meal was 3800 kJ. The protein-rich meal was identical in composition except that 50 g of bovine serum albumin was added. Plasma and samples from the quadriceps femoris muscle (percutaneous ...

The preceding papers of this series have dealt with the classification of the amino acids as essential or non-essential components of the food of man (l-5), the r61e of the caloric intake when amino acids serve as virtually the sole sources of nitrogen (6)) and the quantitative amino acid needs of human subjects as measured by the maintenance of nitrogen equilibrium (7-15). One additional topic...

Several bee species are experiencing significant population declines. As bees exclusively rely on pollen for development and survival, such declines could be partly related to changes in their host plant abundance and quality. Here, we investigate whether generalist bumblebee species, with stable population trends over the past years, adapted their diets in response to changes in the distributi...

We present a generalised framework for analysing structural robustness of metabolic networks, based on the concept of elementary flux modes (EFMs). Extending our earlier study on single knockouts [Wilhelm, T., Behre, J., Schuster, S., 2004. Analysis of structural robustness of metabolic networks. IEE Proc. Syst. Biol. 1(1), 114-120], we are now considering the general case of double and multipl...

Animals need to ingest a full set of essential amino acids through their diet. A new study in Drosophila larvae describes how activation of the kinase GCN2 in three dopaminergic neurons mediates the rejection of amino-acid-imbalanced food.

I . In pregnancy, severe hypoproteinaemia, cirrhosis and anaemia, plasma free a-amino nitrogen (FaAN) was found to be low-ered. The non-essential: essential amino acid ratios, determined by paper chromatography, were increased in hypoproteinaemia and anaemia. 2. The erythrocytic FaAN content increased in early hypoproteinaemia and values lower than normal were found in severe hypoproteinaemia. ...

The experiments of W. C. Rose16 brought to a successful conclusion the work of Osborne and Mendel,12 and that of Willcock and Hopkins; the matter of the protein requirements in nutrition is fundamentally a question of the need for each of the indispensable amino acids (Sherman"9). While the present crisis has intensified the need for evaluating the approximate human requirements for these essen...

Studies by Christensen et wl. (1, 2) and by -4llison and associates (3) have demonstrated that the urinary excretion of peptides is greater than the urinary excretion of free amino acids following the infusion of partial hydrolysates of casein or of fibrin. Christensen and coworkers have shown also that infusion of these hydrolysates results in a greater persistence of peptides in the plasma th...

The nitrogen isotope composition (δ¹⁵N) of different amino acids carries different dietary information. We hypothesized that transamination and de novo synthesis create three groups that largely explain their dietary information. Rats were fed with ¹⁵N-labeled amino acids. The redistribution of the dietary ¹⁵N labels among the muscular amino acids was analyzed. Subsequently, the labeling was ch...