Foam cells excretion

The only receptor-mediated uptake process regulated in macrophages involves suppression of )8-VLDL receptors. This suppression only occurs after extensive cholesterol ester accumulation and can be induced by either j8-VLDL or chemically modified LDL [13]. Lipoprotein uptake by all known receptor systems in macrophages causes a marked stimulation of ACAT activity which results in the massive accumulation of cholesteryl ester droplets in the cytoplasm [13]. Free cholesterol can be excreted from the macrophage if cholesterol-accepting Upoproteins such as HDL are present. The uncontrolled uptake and deposition of cholesteryl esters in macrophages is believed to be the key to formation of the foam cells which are associated with atherosclerosis. 

The treatment using novel ACAT inhibitor pactimibe sulfate (CS-505), avasimibe (CI-1011) (Fig.6), and a potent bile acid binding resin cholestyramine directly affects macrophages in atherosclerotic lesions. They would limit the increase in intracellular free cholesterol by its TC-lowering effect. This would allow free cholesterol to excrete into HDL, restoring the cholesterol influx/efflux balance, thus preventing foam cell formation. (Terasak N. et al. 2007). 

The cultivation medium composition and the proteins excreted by the yeast cells were determined and their influence on the flotation performance was investigated by Bahr et al. [115]. The sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAAGE) and native PAAGE measurements indicated that during the cultivation various glycoproteins were excreted, which were distributed differently between the foam and the flotation residue liquid. A... 

At low dilution rates the foaminess and foam stability were low, because of extracellular Hpids excreted by the cells. This caused low protein enrichment in the foam. 

Cell autolysis can occur with a loss in viability, vitality and cell contents being excreted into the fermenting wort. This has a number of consequences on beer flavour and stability, and especially foam stability. 

The balance between PrA occurring in the fermenting wort as a result of cell autolysis and/or enzyme excretion of whole cells is still an issue to be examined. Nevertheless, the occurrence of active PrA is important because of its negative effect on beer foam stability. 

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