Fat emulsion effects on prothrombin time in warfarin anticoagulated patients: an in vitro study.

The effect of lipid emulsions on prothrombin time in blood from anticoagulated patients was determined. Blood samples were obtained from 23 patients therapeutically anticoagulated with warfarin (prothrombin time 1.3-2.0 x control). Varying amounts of an intravenous lipid emulsion (Intra-lipid) were added to the blood to simulate concentrations seen in vivo with a constant lipid infusion. The prothrombin time was measured on the plasma from these samples and compared to the prothrombin time of the plasma samples without lipid. The mean decrease in prothrombin times were: 0.29 sec at 50 micrograms/ml, 0.23 sec at 100 micrograms/ml, and 0.29 sec at 200 micrograms/ml. All concentrations showed a statistically significant decrease (p less than 0.05) when compared to the control by the Scheffe test. Lipid emulsions appear to decrease the prothrombin times in anti-coagulated patients. The differences however, were small and not of clinical significance at the concentrations tested.

Possible relationship between pervasive developmental disorders and platelet monoamine oxidase activity.

1. The present study was undertaken to determine if the platelet monoamine oxidase (MAO) activity of children with childhood-onset Pervasive Developmental Disorders (PDD), atypical PDD and autistic children differs from MAO of normal children of the same age. 2. The kinetic parameters of MAO activity (Km and Vmax for kynuramine as substrate in 100 mM sodium phosphate buffer, pH 7.4 at 37 degrees C) were determined for platelets from autistic (N = 6), childhood onset PDD (N = 6) and atypical PDD (N = 6) children and 14 controls aged 6-10 years. 3. PDD children had significantly lower Km (4.41 +/- 0.26 vs 5.30 +/- 0.23 microM) and Vmax (16.77 +/- 1.56 vs 22.15 +/- 2.16 nmol h-1 mg protein-1) than control children. The reduction in Vmax was demonstrable in MAO activity measured with 100 microM substrate (14.93 +/- 1.13 vs 20.96 +/- 2.10 nmol h-1 mg-1). 4. These data show that childhood-onset PDD patients, in which the syndrome was complete, presented the lowest levels of platelet MAO activity.