Evidence that lysosomes are not involved in the degradation of myofibrillar proteins in rat skeletal muscle.

To examine the role of lysosomes in the degradation of skeletal-muscle myofibrillar proteins, we measured the release of N tau-methylhistidine from perfused muscle of starved and fed rats in the presence or absence of agents that inhibit lysosomal proteinase activity. After 1 day of starvation, the release of N tau-methylhistidine by perfused muscle of 4-, 8- and 24-week-old rats increased by 322, 159 and 134% respectively. On the other hand, total protein breakdown, assessed by tyrosine release, increased by 62, 20 and 20% respectively.

Sites of protein conservation and loss during starvation: influence of adiposity.

Previous studies have established that older (16 wk) and more obese rats conserve body protein during prolonged starvation. This adaptation is due in part to a curtailment of muscle proteolysis. To determine whether this response occurs also in younger rats and whether protein is conserved at sites other than muscle, studies were conducted in young 6-wk-old rats previously fed either a chow or a high-fat diet before starvation.

Reduced metabolic complications in total parenteral nutrition: pilot study using fat to replace one-third of glucose calories.

The limitations of glucose-based TPN solutions are high glucose concentration, high osmolality, lack of fat, and essential fatty acids, which result in glucose intolerance and hepatotoxic effects. We replaced one-third of the calories in a standard amino acid-glucose solution with Liposyn 10% for 14 days in 23 critically ill men who needed total parenteral nutrition. Serial measurements included weight, albumin, glucose, triglyceride concentrations, and liver function tests.

Hypothalamic knife cut obesity in hyper or hypothyroid rats.

Recent evidence indicates that the paraventricular nucleus of the hypothalamus (PVN) contains both neurons that produce thyrotropic releasing hormone (TRH) and neurons that are destroyed or disconnected by the knife cuts that produce hypothalamic hyperphagia and obesity. This, and other evidence, suggested linkage between thyroid regulation and appetite control. As predicted, hyperthyroidism potentiated and hypothyroidism tempered the weight gains of knife cut rats.

Popliteal artery thrombosis in a young woman, secondary to bony exostosis.

Idiopathic thrombosis of the popliteal artery in young people is exceedingly uncommon. Previously suggested etiologies are cystic adventitial disease, popliteal entrapment syndrome, Buerger's Disease, juvenile arteriosclerosis and synovial cysts. An instance of popliteal artery thrombosis secondary to compression by a bony exostosis is recorded to call attention to this unusual etiological mechanism in a 21 year old woman.

Non-effect of Massachusetts cement kiln dust upon the food intake, body weight, or activity of female rats.

The addition of Georgia cement kiln dust to the diet of cattle or weanling male rats has been reported to increase body weight and feed efficiency. We attempted to replicate these effects by adding kiln dust to the Purina laboratory chow of adult female rats. Massachusetts cement kiln dust caused no significant change in food intake, weight gain, or activity.