Proteomic investigations on the effect of different membrane materials on blood protein adsorption during haemodialysis.

Background: During haemodialysis procedure, the contact of blood with the membrane material contained in the hemodialyser results in protein deposition and adsorption, and surface-adsorbed proteins may trigger a variety of biological pathways with potential pathophysiologic consequences. The present work was undertaken to examine for protein adsorption capacity of two membranes used for clinical haemodialysis, namely cellulose triacetate (a derivatized cellulosic membrane) and the synthetic polymer polysulfone-based helixone.

Materials And Methods: We performed a prospective cross-over study in chronic haemodialysis patients, routinely treated with a cellulose triacetate dialyser (n=3) or with a helixone dialyser (n=3).

Proteomic analysis of protein adsorption capacity of different haemodialysis membranes.

Protein-adsorptive properties are a key feature of membranes used for haemodialysis treatment. Protein adsorption is vital to the biocompatibility of a membrane material and influences membrane's performance. The object of the present study is to investigate membrane biocompatibility by correlating the adsorbed proteome repertoire with chemical feature of the membrane surfaces.

Plasma protein carbonylation in chronic uremia.

Background: Carbonylation is an irreversible modification caused by the introduction into proteins of carbonyl derivatives (aldehydes and ketones), which can alter protein structure and function and lead to cellular dysfunction and tissue damage. Chronic uremia may be associated with an increased carbonyl overload ("carbonyl stress"), though carbonyl formation has been proposed so far for major plasma proteins only. In this study we looked for evidence and for the targets of plasma protein carbonylation in patients on hemodialysis.

Protein-protein interaction heterogeneity of plasma apolipoprotein A1 in nephrotic syndrome.

Apolipoprotein A1 (apoA1) is a component of the high density lipoproteins (HDL) that regulates the transport of cholesterol between the liver and peripheral cells and modulates the removal of any excess of cholesterol from membranes. Any variation in apoA1 composition may modify the plasma lipid profile and be involved in atherogenesis. We investigated apoA1 composition in plasma of 6 children with nephrotic syndrome, a condition characterized by high levels of cholesterol in plasma and by a high risk to develop atherosclerosis.

Beta2-microglobulin causes abnormal phosphatidylserine exposure in human red blood cells.

The exposure of the aminophospholipid phosphatidylserine on the external leaflet of red blood cell plasma membrane can have several pathophysiological consequences with particular regard to the processes of cell phagocytosis, haemostasis and cell-cell interaction. A significant increase in phosphatidylserine-exposing erythrocytes has been reported in chronic haemodialysis patients and found to be strongly influenced by the uraemic milieu. To identify uraemic compound(s) enhancing phosphatidylserine externalization in erythrocytes, we fractionated by chromatographic methods the ultrafiltrate obtained during dialysis, and examined by flow cytometry the effect of the resulting fractions on phosphatidylserine exposure in human red cells.