Oxygen availability as a possible limiting factor in LDL oxidation.

Kinetic studies of copper-induced LDL peroxidation commonly assume that the availability of molecular oxygen in the reaction media is not a limiting factor. The present study reveals that this assumption is valid only at low LDL concentrations. At high LDL concentrations, accumulation of oxidation products, as monitored spectroscopically under conditions of various oxygen concentrations in the medium, comes to a halt when the oxygen concentration in the solution, as measured by an oxygen electrode, decreases to near zero levels.

Alterations in serum leptin in chronic liver disease.

The role of leptin in anorexia associated with liver cirrhosis remains controversial. The aim of this study was to quantify the serum leptin level in patients with hepatocellular or cholestatic liver disease and to assess its relationship with serum insulin, body mass index, and serum lipoproteins. The study population included 30 women, 15 with chronic hepatocellular liver disease and 15 with primary biliary cirrhosis; severity of disease was determined by Child-Pugh and histological criteria, respectively.