摘要:

A simple procedure has been developed for the isolation of coagulation factor VIII (F VIII) from plasma in a form which induces a monospecific antibody in rabbits. Amino acid precipitation from plasma was followed by gel filtration on Sepharose 4B and further purification was achieved by affinity chromatography on heparin-Sepharose. The material so isolated was identified by immunoelectrophoresis and lacked coagulant activity. The antiserum produced in rabbits inhibited F VIII coagulant activity and von Willebrand factor activity as measured by ristocetin platelet agglutination. The isolated IgG fraction insolubilised with CNBr-Sepharose 4B retained the ability to complex with F VIII. This complex possessed F VIII coagulant activity which could be removed in 0.6 M NaCl and dissociated in 8 M urea.

ISSN:1424-8832    

DOI:10.1159/000214276

出版商:S. Karger AG    

年代:1978

数据来源: Karger

摘要:

Factor VIII complex was studied in patients presenting arterial hypertension. Visceral involvement was quantified using a clinical index calculated from ocular fundus, renal function and left ventricular hypertrophy data. A significant correlation was found between the mean arterial pressure, the visceral involvement and the level of complex VIII. Nevertheless, other data obtained in different patients (Conn’s disease) suggest that the visceral involvement (and not the mean arterial pressure) is the main determining factor in the increase of factor VIII comple

ISSN:1424-8832    

DOI:10.1159/000214277

出版商:S. Karger AG    

年代:1978

数据来源: Karger

摘要:

Normal and thrombasthenic platelet membranes are able to specifically bind 14C-ADP (12). According to the concentration of ADP present in the medium, ‘high affinity binding sites’ (Ka = 0.5 × 106M-1) and ‘low affinity-binding sites’ (Ka= 0.05 × 106 M-1) can be recognized. In the present study, dissociation of ADP from the ‘high affinity binding sites’ was measured with six normal and with three thrombasthenic platelet membrane preparations. A 1:100 dilution was used to dissociate the membrane-bound 14C-ADP and the kinetics of the dissociation was determined. The same profile of dissociation (with T 1/2 = 4–10 min at 37 °C) was observed using normal or thrombasthenic membranes. With both preparations, the rate of dissociation was increased (up to T 1/2 = 1 – 3 min) when unlabelled ADP (at concentration higher than 10-5M) was added in the diluting medium. The results confirm the presence of normal ADP binding sites on thrombasthenic platelet membrane and possibly suggest the existence of cooperative interactions between the sites on normal as well as on thromb

ISSN:1424-8832    

DOI:10.1159/000214278

出版商:S. Karger AG    

年代:1978

数据来源: Karger

摘要:

A simple assay method for platelet factor 4 is described. When factor Xa was added to a system containing antithrombin III in excess and heparin in low concentration, the amount of factor Xa immediately inactivated was found to be a function of the concentration of heparin. When an antiheparin such as platelet factor 4 was added, an increase of the residual activity of factor Xa was observed. The magnitude of this increase was shown to be correlated to the amount of heparin inactivation in the system. Platelet factor 4 could be assayed when the concentrations of antithrombin III, heparin, and factor Xa were maintained at a constant level and in excess. As an indicator of the reaction, factor Xa was measured with the chromogenic substrate benzoyl-Ile-Glu-Gly-Arg-p-nitro-anilide (S-2222).

ISSN:1424-8832    

DOI:10.1159/000214279

出版商:S. Karger AG    

年代:1978

数据来源: Karger

摘要:

We have evaluated the effect on the response of citrated platelet-rich plasma to aggregating agents of storage at 4 °C versus room temperature (21 °C) for 2 and 4 h after venipuncture. While there were small decreases in some responses to epinephrine, ADP and collagen attributable to 21 °C storage, only in the case of ristocetin-induced aggregation was a profound difference noted. Platelets stored at 4 °C for 4 h showed no significant change in response to ristocetin. In contrast, those stored at room temperature showed a marked decrease. This change is not likely to be attributable to a change of pH, although pH rose less with storage at 4 °C than at 21 °C. It is recommended that PRP for in vitro testing be stored at

ISSN:1424-8832    

DOI:10.1159/000214280

出版商:S. Karger AG    

年代:1978

数据来源: Karger

摘要:

After injection of urokinase (UK) in normal rabbits and in rabbits with ligated liver, spleen and kidneys, the inactivation rate constant of UK was evaluated by using the disappearance rate of fibrinolytic activity from plasma. A peripheral intravenous injection of UK in normal rabbits induced significant but transient fibrinolytic activity, whereas intraportal injection of UK induced no fibrinolytic activity. However, in rabbits with ligated liver, spleen and kidneys, the fibrinolytic activity sustained for a long period, i.e. the inactivation rate constant of UK was 6 times smaller compared with normal rabbits. The implications of these results are discussed.

ISSN:1424-8832    

DOI:10.1159/000214281

出版商:S. Karger AG    

年代:1978

数据来源: Karger

ISSN:1424-8832    

DOI:10.1159/000214282

出版商:S. Karger AG    

年代:1978

数据来源: Karger

ISSN:1424-8832    

DOI:10.1159/000214283

出版商:S. Karger AG    

年代:1978

数据来源: Karger

ISSN:1424-8832    

DOI:10.1159/000214284

出版商:S. Karger AG    

年代:1978

数据来源: Karger

ISSN:1424-8832    

DOI:10.1159/000214275

出版商:S. Karger AG    

年代:1978

数据来源: Karger