The aim of this study was to compare the secretory response of the vascular wall in vivo to DDAVP (i.v. 0.3 microgram/kg, 30 min) and to venous occlusion (VO, 20 min) in control healthy subjects, ...patients with von Willebrand's disease type I (vWd I) and patients with von Willebrand's disease type III (vWd III). In controls (n = 10) and vWd I (n = 12), DDAVP induced a 2 to 3-fold rise in plasma von Willebrand factor antigen (vWf: Ag), factor VIII coagulant activity (VIII: C) and tissue--type plasminogen activator antigen (t-PA:Ag). VO was less effective in increasing vWf: Ag and VIII:C but produced a greater rise in t-PA:Ag. Large increments (over 10-fold) were observed in plasmin-alpha 2-antiplasmin complexes following both stimuli. In vWd III (n = 10), DDAVP and VO failed to increase vWf:Ag, VIII:C and t-PA:Ag. No significant changes in plasmin-alpha 2-antiplasmin complexes were observed in this group. Moreover, the baseline t-PA:Ag values were significantly lower in vWd III (2.17 +/- 1.13 ng/ml) than in controls (4.84 +/- 1.97 ng/ml, p < 0.001). A significant increase in urokinase--type plasminogen activator antigen (u-PA:Ag) was found only in controls after VO. Neither controls nor patients with vWd showed any changes in plasma fibronectin levels following DDAVP. The low t-PA:Ag results and the abnormal fibrinolytic response to DDAVP and VO in patients with severe (type III) vWd indicate that their endothelial cell abnormality is more extensive than the defect in the synthesis or release of vWf.
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.
The use of the computer cross-match Engelfriet, C. P.; Reesink, H. W.; Engelfriet, C. P. ...
Vox sanguinis,
April 2001, Letnik:
80, Številka:
3
Journal Article
The activity of Polish Blood Transfusion Service (BTS) is based on the Public Blood Transfusion Service Act voted by the Polish Parliament. There are 21 regional blood transfusion centers, one ...military blood transfusion center and one blood transfusion center (BTC) of the Ministry of Internal Affairs. The Institute of Haematology and Transfusion Medicine (IHTM) is responsible for issuing guidelines for blood transfusion medicine. All BTCs must have an accreditation from the Ministry of Health. In Poland, there is a national system of haemovigilance. Hospitals are obliged to immediately report all post‐transfusion complications and ‘near‐miss’ events. Immunological, viral, bacterial as well as transfusion‐related acute lung injury reactions are supervised by IHTM. Qualification improvement and training of personnel is one of the priorities of Polish BTS.
Platelet concentrates (PCs) obtained using old generation of cell separators contain high number of leukocytes. White cell (WBC) contamination and platelet (Plts) number in PCs obtained from ...separator II-nd generation CS-3000 and separators III-rd generations CS-3000 plus and Cobe-Spectra have been determined. PCs from new separators contain the same Plts number as PCs from CS-3000. The average leukocyte count in PCs obtained from CS-3000 was 171.26 x 10(6), whereas WBC number in PCs from CS-3000 plus and Cobe-Spectra were 2.87 and 2.54 x 10(6) respectively. In about 85% of PCs obtained from III-rd generation cell separators the leukocyte count did not exceed 5 x 10(6). This count is considered sufficient to prevent alloimmunization of HLA antigens. The determination of WBC count in every PCs allows to select PCs with fewer than 5 x 10(6) leukocytes and to transfuse them without the necessity of using expensive filters for leukocyte removing.
