Plasma contact activation and decrease of factor V activity on negatively-charged polyelectrolytes.

M C Boffa; B Dreyer; C Pusineri

Home/Archive/PubMed

PubMed · 6719390

Plasma contact activation and decrease of factor V activity on negatively-charged polyelectrolytes.

M C Boffa·B Dreyer·C Pusineri

View original source ↗Export metadata ↓

Abstract

The effect of negatively-charged polymers, used in some artificial devices, on plasma clotting and kinin systems was studied in vitro using polyelectrolyte complexes. Contact activation was observed as an immediate, transient and surface-dependent phenomenon. After incubation of the plasma with the polymer a small decrease of factor XII activity was noticed, which corresponded to a greater reduction of prekallikrein activity and to a marked kinin release. No significant decrease of factor XII, prekallikrein, HMW kininogen could be detected immunologically. Only the initial contact of the plasma with the polyelectrolyte lead to activation, subsequently the surface became inert. Beside contact activation, factor V activity also decreased in the plasma. The decrease was surface and time-dependent. It was independent of contact factor activation, and appeared to be related to the sulfonated groups of the polymer. If purified factor V was used instead of plasma factor V, inactivation was immediate and not time-dependent suggesting a direct adsorption on the surface. A second incubation of the plasma-contacted polymer with fresh plasma resulted in a further loss of Factor V activity.

Explore related subjects

Electrolytes Factor V Factor XII Humans Kininogens Polymers Prekallikrein Surface Properties Time Factors Journal Article Research Support, Non-U.S. Gov't

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

M C Boffa, B Dreyer, C Pusineri. 1984-02-28. Plasma contact activation and decrease of factor V activity on negatively-charged polyelectrolytes.. https://pubmed.ncbi.nlm.nih.gov/6719390/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed1995

The Dukhin-Deryaguin equation for the electrophoretic mobility in monovalent electrolytes with arbitrary ion mobilities.

The Dukhin-Deryaguin equation, used in the modern theory of electrophoresis for the calculation of electrophoretic mobility (EPM) in the region of double layer polarization, is known from literature [4-6] in its form (DD1) valid for the equal mobilities of the cation and anion in solutions of symmetrical electrolytes. Here we describe the other version of this equation (DD2), for arbitrary ion mobilities in 1:1 electrolytes. The EPMs calculated from this latter version are in good agreement with an exact computer solution [12]. The use of DD2 is illustrated in a series of EMP vs. IgC curves, calculated for selected examples of negatively charged lipid membranes. In addition, we describe two simplified versions of DD2, which are valid, respectively, for the high zeta potentials and when the electroosmotic component of ions' fluxes at the charged surface is neglected. Comparing DD2 with DD1 shows that the latter equation results in an error which may exceed the experimental dispersion of EPM values in the absence of specific ion binding. This error is reduced if the counter-ion binding is not small; hence, DD1 may also be used in some cases for solutions with arbitrary ion mobilities.

Electrolytes↗

PubMed1995

Sequential urinalysis improves evaluation of fetal renal function in obstructive uropathy.

OBJECTIVES: The purpose of our study was to determine whether sequential vesicocenteses improve the evaluation of renal damage, compared with single urine sampling in obstructive uropathy. STUDY DESIGN: A total of 29 fetuses with complete obstructive uropathy underwent a minimum of three sequential complete vesicocenteses at 48- to 72-hour intervals. First and last urine values were analyzed for multiple parameters. The ability of first versus last urine values to detect the presence of renal damage was compared according to postnatal or fetal autopsy information. RESULTS: Fetuses with minimal renal damage had patterns of decreasing hypertonicity and last urine values below cutoff thresholds indicative of favorable prognosis. Fetuses with significant renal damage had higher initial values and patterns of increasing hypertonicity. For five of six parameters, last urine samples were more predictive of renal damage than first urine samples. CONCLUSION: Last urine values together with pattern-of-change trend analysis after serial vesicocenteses improve diagnostic precision in fetuses with complete obstructive uropathy.

Electrolytes↗

PubMed1995

Salt-nucleic acid interactions.

Coulombic interactions of salt ions with polymeric and oligomeric nucleic acids in solution have large and distinctive effects on ion distributions, on thermodynamic coefficients, and hence on equilibrium processes involving nucleic acids, such as their conformational transitions and binding interactions. In experimental or theoretical studies where an oligonucleotide is taken to represent the corresponding polynucleotide, the impact of coulombic end effects on molecular and thermodynamic properties must be taken into account. Observable consequences of coulombic interactions in nucleic acid solutions have been calculated by using models with varying degrees of detail and methods formulated at varying levels of rigor. From comparisons of experimental results with predictions of the prevalent theoretical approaches, this review concludes that the more rigorous methods have proved capable of accounting for thermodynamic (and some molecular) consequences of coulombic interactions with a minimal number of preaveraged parameters that represent the most important structural features of the nucleic acid solution.

Electrolytes↗