Biomedical subjects
L Kirshner
Publications and source records attributed to L Kirshner.
Hemifield relative motion bias in adults monocularly enucleated at an early age.
A psychophysical study of relative motion discrimination for six subjects monocularly enucleated within 24 months of birth showed no significant difference in their thresholds for detecting relative velocity when compared with age matched control subjects. The study however highlighted a bias for the control group, age matched normals, which is consistent with a hemifield anisotropy for motion in normal observers reported by Smith and Hammond [(1986) Perception, 15, 111-117]. The bias however was found to be reversed for enucleates. This difference and individual differences reported in the Smith and Hammond study are discussed in terms of possible developmental changes which emerge when stereopsis is absent or weak.
Interactions of human platelets with insoluble anticoagulant modified polystyrene resins.
The interactions of two insoluble anticoagulant polystyrene derivatives with human platelets were studied in an in vitro system similar to a chromatography column. Blood was pumped through the column and platelets were counted before and after passage through the column. Interaction of platelets with the beads led to retention of platelets in the column. The same experiment was performed with several donors. Different pretreatments were assayed and compared for both materials: platelet poor plasma, antithrombin III-depleted platelet poor plasma and an antithrombin III solution. Platelet retention depends on the polymer composition: the material containing glutamic acid sulphamide groups, which has a larger anticoagulant activity in plasma than the materials only substituted by sulphonate groups, is always less reactive towards platelets. The differences in the effects of pretreatment on both materials can be correlated with the variations of antithrombin adsorption on the synthetic surfaces.