PubMed Health⌕ Search

Biomedical subjects

P Konstantin

Publications and source records attributed to P Konstantin.

4 recordsLinked to original sources
PubMed1986

Polycarbonate-polyether (PC-PE) flat sheet membrane: manufacture, structure and performance.

Polycarbonate-polyether (PC-PE) polymer, prepared by solution or interfacial polymerization, was used to produce a dry PC-PE diffusion membrane by means of the phase inversion technique. The mechanical stabilities and diffusive permeabilities of chloride, phosphate and vitamin B12 were determined for this membrane. Additionally, close control over manufacturing parameters allowed the study of the effects of varied membrane thickness (at constant ultrafiltration rate) and varied ultrafiltration rate (at constant membrane thickness) on solute diffusive permeabilities. Both increased ultrafiltration rate and decreased thickness resulted in an increase in solute diffusive permeabilities.

Humans↗
PubMed1986

Preliminary report on complement activating potential of polycarbonate membrane.

Clinical as well as laboratory studies have been employed to assess the complement activating potential of polycarbonate membrane hemodialyzers. Blood samples from a group of patients undergoing sequential maintenance hemodialysis with cuprophane, polyacrylonitrile and polycarbonate devices were evaluated to define plasma levels of C3a antigen and leukocyte counts during the initial phases of hemodialysis. While polyacrylonitrile dialyzers did not activate complement to a significant extent, we did observe transient elevations in the plasma concentration of C3a and corresponding diminutions in the granulocyte counts of patients dialyzed with both cuprophane and polycarbonate dialyzers. However, polycarbonate devices appeared to activate complement to a lesser degree than cellulosic dialyzers. Laboratory evaluation of these three different types of dialyzers also provided evidence that polycarbonate membranes did not appear to activate human complement as readily as cuprophane. These observations suggest that polycarbonate membranes display complement-related biocompatibility properties that are intermediate between those of cuprophane and polyacrylonitrile.

Cellulose↗
PubMed1979

Effect of hemoperfusion with coated and uncoated charcoal on human blood in vitro.

During 4 hours, in-vitro hemoperfusion of human blood was performed in 4 series of experiments: control, cellulose coated charcoal, polyacrylohydrogel coated charcoal and uncoated charcoal. In the control series little change on corpuscular elements and electrolytes was observed. In all hemoperfusion series there was little change of RBC and uniformly a marked fall of the granulocyte count. Platelet- and lymphocyte counts were significantly less affected by cellulose coated charcoal than by the other preparations. Coated and uncoated charcoal absorbed avidly calcium and glucose from the blood. By contrast the potassium level decreased moderately with polyacrylohydrogel coated and uncoated charcoal, whereas the opposite was observed with cellulose coated charcoal.

Blood Cell Count↗