Methodological problems in testing of platelet adhesiveness.

Abstract

Various methods for testing platelet adhesiveness are discussed. A mathematical approach has demonstrated that the interstitial volume in a column with equal‐sized, spherical glass beads is not dependent on the size of the glass beads. The total surface is inversely proportional to the radius of the glass beads. Other parameters such as the mean circumference of the glass beads in a cross‐section of a column and the mean thickness of fluid can be calculated.Experiments with columns of various lengths and breadths, contact times, rates of flow, sampling times, size and nature of glass beads have been performed. The results stress the importance of the contact time of the platelets, while other parameters will slightly modify the effects. By fractionating sampling an enhancing principle of platelet adhesiveness was found in many experiments. Further investigations suggested that this was probably due to an accumulation of the R‐factor of Hellem, later demonstrated by him and collaborators as ADP.