Simultaneous analysis of low plasma levels of deuterium-labeled saturated and unsaturated fatty acids as t-butyldimethylsilyl esters

A sensitive and accurate method for detection and quantitation of deuterated fatty acids in the presence of large amounts of unlabeled fatty acids is described using mass fragmentography in combination with the preparation of tertiarybutyldimethylsilyl esters (t-BDMS). The method has been applied to determination of deuterated stearic, oleic, elaidic and linoleic acids in human plasma lipoproteins following duodenal perfusion with a micellar mixture of acids. Over a concentration range of 10-1000 ng/ml, the average coefficient of variation for the linoleate was 3% and for the oleate (elaidate) ester was 2%.

Total body protein turnover and growth in children: is it a futile cycle?

Rates of total body protein turnover during growth greatly exceed those necessary for net protein deposition. The excess protein synthesis would appear to be energy wasteful. However, a constant relationship is noted between whole body protein synthesis and basal energy needs, except during periods of rapid growth and development (newborn and adolescence). We suggest that whole body protein turnover is regulated by basal energy needs. The excess synthesis seen during periods of rapid growth is probably necessary to permit development and remodelling of tissues and organs to take place coincident with a mere increase in size.

Pituitary Tumour

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