ABSTRACT
The effects of intravenous administration of DDAVP to blood donors and the use of DDAVP plasma for the production of cryoprecipitate in the closed thaw-siphon system were evaluated. DDAVP treatment produced on the average a 3.2-fold rise in plasma levels of factor VIII. Von Willebrand factor antigen increased to a lesser extent. Cryoprecipitate prepared from 220-280 ml aliquots of DDAVP stimulated donor plasma contained 472 +/- 210 units of factor VIII and 276 +/- 130 units of von Willebrand factor antigen. The average yield of factor VIII was 57% of that in the prefrozen plasma. The specific activity of factor VIII in cryoprecipitate was 0.77 +/- 0.44 U/mg protein, comparable to that for intermediate purity concentrates. Thus, by the use of DDAVP and the thaw-siphon technique it is possible to produce cryoprecipitate 4-7 times as potent as conventionally manufactured preparations.
Subject(s)
Blood Donors , Deamino Arginine Vasopressin/administration & dosage , Factor VIII/metabolism , Chemical Precipitation , Deamino Arginine Vasopressin/pharmacology , Factor VIII/drug effects , Factor VIII/isolation & purification , Freezing , Humans , Male , Reference Values , von Willebrand Factor/isolation & purificationABSTRACT
The authors tried to explain whether granulocytes obtained by sedimentation on dextran can be stored, under what conditions, and for how long time. For this purpose leukocyte concentrated were stored at 4-6 degrees C and 20-24 degrees C for up to 48 hours, and the count and percent proportions of leucocytes, granulocyte viability, their phagocytic index, chemotactic ability and ATP content were determined. The investigations demonstrated a progressing decrease of the biological viability of granulocytes after 24 hours, and a further decrease after 48 hours. Particularly pronounced and early changes were noted in the chemotactic activity and ATP content. A beneficial effect was noted of higher storage temperature (20-24 degrees C) on the maintenance of chemotactic activity. The other parameters were not temperature-dependent. It seems that under such conditions leucocyte concentrates should be transfused preferably immediately after their preparation.
