The effects of total parenteral nutrition on immunodepression due to malnutrition.

An experimental study was performed in 16 dogs to investigate the effects of sub-acute malnutrition on humoral and cellular immunity and phagocytic functions and, subsequently, to investigate the ability of total parenteral nutrition (TPN) to restore abnormal immunological variables. Deficiencies of IgG, C3, primary immune response to sheep red blood cells (SRBC),lymphocyte counts, lymphocyte response to phytohemagglutinin (PHA), and neutrophi chemotaxis were found to be caused by malnutrition. Nutritional repletion by means of TPN resulted in a return to normal or supranormal serum concentrations of IgG, IgM, and C3, and the primary immune response to SRVC was prompter and higher.

Histopathological studies on dog lymphoid structures during malnutrition and total parenteral nutrition.

Lymphoid tissues of six malnourished dogs were histologically evaluated and compared to the same lymphoid structures of dogs nutritionally repleted by means of total parenteral nutrition (TPN). The results show that thymus, spleen, lymph nodes and Peyer's patches are markedly atrophic and severely cell depleted in malnourished dogs, and provide evidence that subsequent TPN therapy stimulates and supports lymphoid cell prolipheration, leading to cell repopulation of previously depleted lymphoid structures.

Cardiac muscle models for both isotonic and isometric contractions.

The choice of a suitable muscle model consistent with the mechanical behaviour of Rat papillary muscle at rest or during isotonic or isometric contraction has been considered. Three different preload levels within the ascending limb of the Frank-Starling curve have been used in five papillary muscles. Series elastic (SE) and parallel elastic (PE) length-tension relationships have been evaluated according to five mechanical muscle models using data from systolic and diastolic quick-release manoeuvres.