ABSTRACT
To improve the safety of plasma derived factor VIII (FVIII) concentrate, we introduced a final super heat treatment (100 degrees C for 30 min) as additional virus inactivation step applied to a lyophilized, highly purified FVIII concentrate (100 IU/mg of proteins) already virus inactivated using the solvent/detergent (S/D) method during the manufacturing process. The efficiency of the super heat treatment was demonstrated in inactivating two non-lipid enveloped viruses (Hepatitis A virus and Poliovirus 1). The loss of FVIII procoagulant activity during the super heat treatment was of about 15%, estimated both by clotting and chromogenic assays. No substantial changes were observed in physical, biochemical and immunological characteristics of the heat treated FVIII concentrate in comparison with those of the FVIII before heat treatment.
Subject(s)
Factor VIII/isolation & purification , Hepatovirus/isolation & purification , Poliovirus/isolation & purification , Animals , Antigens, Viral/biosynthesis , Disease Models, Animal , Factor VIII/adverse effects , Factor VIII/immunology , Female , Hepatovirus/immunology , Hot Temperature , In Vitro Techniques , Mice , Mice, Inbred C57BL , Poliovirus/immunology , RabbitsABSTRACT
A simple method of irradiating cells in vitro with beta particles is to add the beta-emitter to a cell suspension; various dosimetric aspects of this procedure have been investigated. It is shown that, due to the different water content of the various constituents of a blood cell suspension, the average dose D beta absorbed by a certain type of cells for a tritium nominal concentration Co and an irradiation time t is given by D beta(t) = KEnCo eta t. Typical values of the factor eta are calculated for lymphocytes. A series of experiments has demonstrated that whilst the uptake phase has negligible effect on the dose, a significant error may arise during washing-out because a proportion of the activity remains in the cells.
