Erythrocyte interactions - Comparison of the aggregation power of polymer molecules used in medicine - Not only size does matter.

Background: Different colloids are used as a part of solutions for fluid resuscitation and organ preservation: hydroxyethyl starches (HES), dextran (Dx), polyethylene glycols (PEG), polyvinyl pyrrolidone (PVP). Some of the problems associated with their application are addressed to alteration in erythrocyte (ERY) rheology.

Objective: We intended to estimate in vitro and compare the aggregation power (AP) of these molecules related to ERY interactions.

Quantitative expediency assessment of the zeta sedimentation ratio and the plasma viscosity in arterial hypertension research.

Accepted methods of the ESR methodology (the Westergren mode and ZSR mode) and its alternative the plasma viscosity were tested for diagnostic utility in pregnancy induced hypertension and pre-eclampsia. The receiver-operating characteristic curve (ROC) analysis approved moderate diagnostic accuracy for the ESR methodology and supplied support for its preliminary estimated cutoff values but failed to indicate cogent discernment of pathology by values of plasma viscosity. Likely pathological whole blood alterations boost the erythrocyte aggregation while the concomitant depletion of macromolecules degrades plasma viscosity values.

Studies on the aggregation behaviour of pegylated human red blood cells with the Zeta sedimentation technique.

Covalent binding of poly(ethylene glycol), abbreviated as PEG, to red blood cells (RBC) surface leads to masking of the RBC blood group determinants and the PEG layer on the cell surface sterically hinders RBC-RBC and RBC-plasma protein interactions. We cross-linked linear mPEG-SPA of various molecular mass (2000, 5000, 20000) to washed human RBC under varying incubation ratios polymer to RBC. The electrophoretic mobility (EM) of the modified RBC decreases with increasing of chain length and concentration of PEG up to 50%.

On the interrelationships between erythrocyte aggregation, plasma viscosity and the total peripheral resistance in arterial hypertension.

A probable conjunction of hemodynamic- and rheological variables was tested in hypertensive patients. Most pronounced correlation was fixed for some indices (sizable in value for plasma viscosity and small but distinct for blood pressure and ZSR) vs. total peripheral resistance.