RESUMEN
During cryopreservation of leukocytes, a great part of the granulocytes is injured. The latter is responsible for aggregate formation in the suspension and a loss in the number of preserved cells. The formation of aggregates in the suspension is potentiated in the presence of serum in the cryoprotective medium. On the other hand, the presence of sugar (sucrose, lactose, dextrose) in the washing solution diminishes the aggregate formation, the latter effect being directly proportional to the final concentration of the sugar in the suspension. The aggregates contain mainly cells and very rarely amorphous or fibrous zones. They appear only in the presence of serum. Their formation is not connected with presence of traces of fibrinogen in the serum.
Asunto(s)
Conservación de la Sangre , Leucocitos/citología , Carbohidratos , Agregación Celular , Crioprotectores , Congelación , Humanos , Técnicas In Vitro , SolucionesRESUMEN
Thrombin for topical hemostasis can be prepared from bovine or human blood plasma. The prothrombin is isolated by means of adsorption on DEAE-Sephadex A-50 and consecutively activated by CaCl2 and thromboplastin. Thrombin is precipitated and purified by acetone. The specific activity of the thrombin preparation is 122 + 23 IU/mg protein while the yield is 36,360 +/- 6623 IU/liter plasma.
Asunto(s)
Trombina/aislamiento & purificación , Administración Tópica , Animales , Bovinos , Cromatografía por Intercambio Iónico , Humanos , Trombina/administración & dosificaciónRESUMEN
Erythrophagocytosis is conditioned by serum immunoglobulins. The extent of phagocytosis depends on the haematocrit of the red cell suspension pretreated with formaldehyde. The higher the haematocrit value, the lower will be the extent of phagocytosis. Phagocytosis of white blood cells pretreated with formaldehyde by granulocytes and monocytes is conditioned mainly by a thermolabile fraction of the serum, probably the complement.