摘要:

Factor VIII coagulant antigen (FVIIl·Ag) and FVIII coagulant activity (FVIIl·C) were measured in 102 healthy individuals, in 5 hemophilia A carriers and in 21 hemophilia A patients before and after infusion of heat-treated high-purity FVIII concentrates. Factor VIIl·Ag was determined by a solid-phase micro enzyme-linked immunosorbent assay (ELISA) using monoclonal antibodies and by a conventional solid-phase immunoradiometric assay (IRMA). Factor VIII:C was assessed using a one-stage assay. The micro ELISA was decidedly more precise than the IRMA. There was a close correlation between the results obtained by the three assays in the plasma of healthy subjects and in hemophilia A carriers. After transfusion of FVIII concentrates to hemophilia A patients, the FVIIl·Ag recoveries were significantly lower than the FVIIl·C recoveries and the biological half-life of FVIIl·Ag was significantly shorter than for FVIIl·C. The calculated half-life of FVIIl·C was longer than in any previou

ISSN:1424-8832    

DOI:10.1159/000215740

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

A fast-migrating precipitin peak which showed a reaction of partial immuno-chemical identity with the major von Willebrand factor (vWf) component was detected by crossed immunoelectrophoresis in agarose gel in plasma but not in platelets from a patient with type IIA von Willebrand’s disease (vWD). Another patient undergoing urokinase therapy had a vWf fragment in plasma which was antigenically cross-reactive with the major vWf component. When plasma from both patients was mixed and electrophoresed together in the first dimension, two fast-moving precipitin arcs were demonstrated in the second dimension. These data indicate that two different kinds of vWf fragments can be generated in viv

ISSN:1424-8832    

DOI:10.1159/000215741

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

Recent studies have reported an interaction of albumin with polymerizing fibrin, resulting in a narrowing of gel fibers. It has been postulated that albumin interacts with the E domain resulting in delayed and thus altered polymerization. Utilizing turbidity techniques, the impact of human albumin on gels of human fibrin, clotted with human thrombin, was studied. The addition of albumin, at concentrations from 3 to 30 µM, to 1 mg/ml fibrin gels produced less than a 10% change in either the kinetics of turbidity increase or the subsequent fiber mass-length ratio. For a given calcium concentration, saturation of albumin’s calcium-binding capacity by prior dialysis ablated even these small effects. Given these findings, it seems unlikely that albumin imposes a physiologically significant influence on fibrin polymerization. Structural changes secondary to albumin-mediated enhancement of factor XIII activity remain a possibili

ISSN:1424-8832    

DOI:10.1159/000215742

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

Antithrombin III (AT III) functional levels are much lower in serum than in plasma; during oral anticoagulation this difference is reduced. Plasma and serum of 172 patients taking vitamin K antagonists were tested for AT III antigen and both AT III heparin cofactor and anti-Xa heparin cofactor. Crossed immunoelectrophoresis of AT III on heparin-agarose was also carried out in plasma and serum. The patients were divided into four groups: (1) international normalized ratio (INR) 9.3–4.1, n = 25; (2) INR 4.0–2.5, n = 73; (3) INR 2.4–2.0, n = 40, and (4) INR 1.9–1.5, n = 34. 66 healthy subjects were used as controls. Plasma levels of AT III antigen, AT III heparin cofactor, and anti-Xa heparin cofactor were the same in all groups. In all groups all serum AT III parameters were higher than in controls; crossed immunoelectrophoresis of AT III on heparin-agarose indicated that this finding was due to a lower formation of complexed AT III in serum. AT III heparin cofactor serum values were the same whatever the INR over a large range (9.3–1.5); the highest anti-Xa heparin cofactor serum levels were noted in the groups treated more intensely (groups

ISSN:1424-8832    

DOI:10.1159/000215743

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

In a venous thrombosis model in the rat obtained by ligation of the inferior vena cava, the effects of standard heparin and CY 216, a low molecular weight heparin fraction, are compared. At a dosage of less than 2 mg/kg b.w. CY 216 is an effective antithrombotic, whereas standard heparin is not.

ISSN:1424-8832    

DOI:10.1159/000215744

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

The feasibility of employing the rat as an experimental model for investigation of full-dose heparin anticoagulation was assessed. Striking similarities were found to exist between rats and humans regarding (1) baseline-activated partial thromboplastin time (APTT) values, and (2) dosage per kilogram of heparin required to produce an APTT value of 1 ½-3 times normal, the clinical definition of full-dose heparinization. Based upon these similarities, it appears that the rat can effectively serve as an experimental model for investigating the effects of heparin in humans

ISSN:1424-8832    

DOI:10.1159/000215745

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

Platelet count is positively correlated with the white cell count in healthy males aged 20–68 years (p < 0.002) and in healthy medical students of both sexes aged 18–22 years (p < 0.0001). Platelet count is also positively correlated with red cell count in healthy males (p < 0.02). Red cell count is positively correlated with white cell count in the older healthy males (p < 0.02) and in the male medical students (p < 0.003). These findings provide support for the concept of a single hormone-dependent pluripotent stem cell whose effect is seen concomitantly in all circulating blood cells. The white cell count and platelet count correlation is less significant in the males aged 35 or above which may represent the development of pathological mechani

ISSN:1424-8832    

DOI:10.1159/000215746

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

Platelet lysates were obtained from suspensions of normal washed platelets by freeze-thawing or Triton X-100 lysis. The resultant platelet lysates contained 0.34 ± 0.15 U/109 platelets (n = 8) of von Willebrand factor antigen (vWf:Ag) as determined by radio-electroimmunoassay using a monospecific antibody to vWf:Ag. The vWf:Ag level was higher in platelet lysates prepared from freshly drawn blood than from outdated platelet packs. Platelet lysates from patients with severe von Willebrand’s disease type I (n = 2) did not contain detectable vWf:Ag. When normal platelet lysates were analyzed by radiocrossed immunoelectrophoresis in agarose using a monospecific polyclonal antibody to plasma vWf:Ag, two immunochemically identical precipitin peaks were seen. One of the platelet vWf:Ag peaks corresponded in its electrophoretic mobility to plasma vWf:Ag, while the other peak, i.e. platelet vWf:Ag-peak II, migrated to a more anodal position. The presence of the platelet vWf:Ag-peak II suggests structural differences between plasma and platelet vWf:Ag and illustrates previously unrecognized heterogeneity of platelet vWf:

ISSN:1424-8832    

DOI:10.1159/000215747

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

Using high-resolution real-time ultrasound to monitor platelet aggregation and plasma clotting, the effect of protamine on platelets was evaluated in a dynamic system of plasma in vitro. Protamine induced platelet aggregation preceding plasma clotting at both low (1.6 s-1) and moderate (22.6 s-1) shear rates. The onset of aggregation and clotting was accelerated at the higher shear rate. Low-shear clots were heterogeneous on ultrasonic imaging, whereas moderate-shear clots were more densely homogeneous. Protamine-induced platelet aggregation was reversed by additional heparin. Pretreatment of plasma with pros-tacyclin prevented protamine-induced aggregation, but clot formation occurred. However, such clots were less echogenic. EGTA and hirudin inhibited both aggregation and clotting. Our ultrasonic aggregometry showed that platelet aggregation was induced by protamine before clots formed, and that not only shear rate but platelet activation might affect the rate and composition of plasma clots.

ISSN:1424-8832    

DOI:10.1159/000215748

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

In the isolated perfused pig ear, batroxobin caused a dose-dependent increase in the release of plasminogen activator. The activator-releasing effect required the presence of the active enzyme. The activator released was of the tissue-type.

ISSN:1424-8832    

DOI:10.1159/000215749

出版商:S. Karger AG    

年代:1987

数据来源: Karger