Search

The automated single cell electrophoresis microscope Parmoquant has been used for the discrimination of lymphocytes and the study of the interaction of substances with cells and synthetic particles. Electrophoretic histograms allowed the determination of changes in the proportion of lymphocyte populations after kidney transplantation, during dialysis treatment, open heart surgery and during pregnancy. Discrimination of leukemic cells on the basis of electrophoresis was used as an additional parameter in diagnosis. In a mouse tumor model, histogram determination enabled the in vivo effect of the tumor necrosis factor on immune cells to be evaluated. Cell electrophoresis was shown to be suitable to detect the influence of antibodies, lectins and bacteria on the cell surface. Protein adsorption was studied on synthetic particles using cell electrophoresis. This method was applied to investigate the phenomena of blood interaction with biomaterials used in artificial organs and to determine differences in the protein composition of serum or other body fluids connected with diseases.

Blood compatibility is determined by interactions at the blood-material interface that depend on the material surface chemical structure. Through selective modifications of the chemically reactive hydroxyl groups of cellulose, the aim was to improve the biocompatibility of cellulose membranes. The number of potentially reactive hydroxyl groups on the cellulose membrane surface were reduced through isocyanate cross-links or through the introduction of hydrophilic, hydrophobic, or ionic functionalities by graft copolymerization. To assess blood compatibility, levels of C3a desArg were determined in plasma after membrane contact. Using the electrophoretic mobility test, the release of cytokines were measured after in-vitro incubation of mononuclear cells with membranes. Adsorption of 131J-human fibrinogen was additionally investigated. With respect to the biocompatibility parameters selected, the modified cellulose membranes show improved in-vitro blood compatibility in comparison to unmodified cellulose membranes.

In accordance with earlier results the electrophoretic mobility of lymphocytes is decreased by horse anti-human lymphocyte globulin (AHLG), which correlates with the results of the rosette inhibition test. Under the influence of AHLG, the distribution of the electrophoretic mobilities of lymphocytes shows a characteristic change. In some of the AHLG samples, the antilymphocyte action is accompanied by an antithrombocyte effect. The resulting decrease in the electrophoretic mobility of platelets correlates with the thrombocytopenic effect in vivo. The variation of pH or ionic strength leads to changes of the AHLG effects. The in vivo influence of AHLG on the distribution of the electrophoretic mobility of peripheral blood lymphocytes and platelets is discussed.

The release of biological active factors from blood cells, e.g. interleukin 1, is of importance with regard to the bioavailability testing of membranes for extracorporeal blood purification. The data from an in vitro system of cytokine release may show a connection between complement activation and cytokine (interleukin) release of membranes. In contrast the results of the generation rate of beta 2-microglobulin did show no definite reference to complement activation or cytokine release. Further time-dependent investigations of the generation rate beta 2-microglobulin are necessary.

Determining the relative percentage of LMC in PBL histograms of RDT patients during hemodialysis we observed a temporary decrease of the LMC proportion during the first 15 minutes of hemodialysis using Cuprophan in contrast to AN 69S and MC Cellulose. These results correlate with the increase of C3a plasma concentration and the decrease of total count of granulocytes. In all investigated RDT patients higher proportions of LMC could be found in relation to healthy donors already before dialysis treatment. Our study therefore seems to indicate that the application of cell electrophoresis is a useful method for the characterization of lymphocytes during extracorporeal circulation as an additional parameter of blood compatibility.

In 111 patients (control group, dialysis patients, kidney recipients) the behaviour of T lymphocytes was observed using an automatic measuring apparatus ( Parmoquant cytopherometer ) and the spontaneous rosette test. The Parmoquant method gives no information on the process of rejection, but it helps to identify risk situations due to bacteria of viruses. In cases of rejection after the second post-operative week, the results of the two methods are reversed.