摘要:

A number of new screening techniques to detect the tendency to hypercoagulability in children with familial hypercholesterolemia is presented. The use of Thrombokinetics (TKG®) and the introduction of a quotient as a new parameter are discussed. The new techniques are compared with the conventional methods. The link of an increased quotient with the activated stage of factor VII has been shown in a pilot study. For the definition of normal values there is a need of a normal pool which has been critically prepared

ISSN:1424-8832    

DOI:10.1159/000215104

出版商:S. Karger AG    

年代:1984

数据来源: Karger

摘要:

Five commercial factor VIII (FVIII) concentrates and three prothrombin complex concentrates (PCC) were studied with reference to the qualitative evaluation of factors II, IX, fibronectin, α2-antiplasmin α2-AP), antithrombin III (AT-III) and subunits A and S of FXIII by crossed-immunoelectrophoresis (CIE) and von Willebrand factor antigen (vWF: Ag) by radio-CIE. This latter protein had a different pattern with the absence or a decrease of larger forms and the presence of a fast-moving precipitating peak, suggesting degradation of the vWF:Ag in FVIII concentrates. In contrast, the electrophoretic mobility of fibronectin, α2-AP and AT-III was normal. All PCC showed a more anodic mobility of factor IX. Α2-AP also exhibited a different electrophoretic pattern to that of normal plasma. Abnormality of AT-III was also found in heparin-binding studies. The techniques used in the purification procedures are probably the mechanism responsible for the partial denaturing of these prote

ISSN:1424-8832    

DOI:10.1159/000215105

出版商:S. Karger AG    

年代:1984

数据来源: Karger

摘要:

We compared site and severity of bleeding in 46 patients with cirrhosis of the liver and accelerated fibrinolysis (defined as a dilute whole-blood clot lysis time 4 h). Patients with accelerated fibrinolysis had a significantly higher incidence of severe soft-tissue bleeding after trauma and a trend toward increased intracranial bleeding. Mucosal, postoperative, and gastrointestinal bleeding were equally frequent in the two groups. The median partial thromboplastin time was significantly longer, and the median bilirubin and fibrin/fibrinogen degradation product levels were significantly higher in the group with accelerated fibrinolysis, but median prothrombin time, platelet count, and levels of fibrinogen and serum albumin were comparable. The fibrinolytic inhibitor ε-aminocaproic acid successfully controlled bleeding in 4 of 6 cases used. Accelerated fibrinolysis may predispose patients with cirrhosis to soft-tissue and intracranial bleeding

ISSN:1424-8832    

DOI:10.1159/000215106

出版商:S. Karger AG    

年代:1984

数据来源: Karger

摘要:

The ability of a low-molecular-weight heparin to bind in vivσto the aortic endothelium in rabbits, compared with that of unfractionated extractive sodium heparin (UHEP), was investigated. For this purpose a low-molecular-weight heparin (LMWHEP) fraction (CY 216 A, 4,000–5,000 daltons) and an extractive UHEP (average 17,000 daltons) were labeled with 99mTc and injected (0.2, 0.6, and 1.2 mg/kg) intravenously in groups of 6 rabbits. The binding to endothelium was then measured by counting the radioactivity of samples of abdominal aorta. Both heparins bound to endothelium with a fast, saturable, and reversible binding. No significant difference in the total bound radioactivity was found between the two heparins, suggesting that the investigated LMWHEP retains the ability to bind to the endothelium, contributing to its athrombogenic properti

ISSN:1424-8832    

DOI:10.1159/000215107

出版商:S. Karger AG    

年代:1984

数据来源: Karger

摘要:

We have observed that high-resolution ultrasonic imaging can be used to detect and measure the size and sedimentation of large human platelet aggregates formed in vitro. At progressively lower shear rates, individual platelet aggregates grew in cross-sectional area from the limit of ultrasonic detectability of less than 1 mm2 at moderate shear rates to an approximate mean area of 25 mm2 at zero shear. Platelet aggregates tended to sediment at mean shear rates higher than zero shear. At a shear rate of 5.5 s-1, 70% of platelet aggregates had settled, and at 1.6 s-1, 90% had settled to the dependent half of horizontal tubes in less than 15 s. Ultrasonic aggregometry of platelets may be a valuable technique for investigation of platelet dynamics under controlled flow conditions in vitro.

ISSN:1424-8832    

DOI:10.1159/000215108

出版商:S. Karger AG    

年代:1984

数据来源: Karger

摘要:

Drug-induced thrombocytopenia is a common acquired hemorrhagic disorder. In this study 32 patients with drug-induced thrombocytopenia were examined with the anti-globulin consumption assay. Platelet-associated IgG was elevated in 19 of 20 patients that were analyzed. An increase in serum platelet bindable IgG was observed in 24 subjects after the addition of various drugs (acetylsalicylic acid, noraminopyrine, antibiotics, sulfamides, digoxin, heparin and chenodeoxycholic acid). These findings are significant for the presence of drug-dependent platelet antibodies.

ISSN:1424-8832    

DOI:10.1159/000215109

出版商:S. Karger AG    

年代:1984

数据来源: Karger

摘要:

Prostacyclin (PGI2) is a potent endogenous inhibitor of platelet aggregation. The effect of PGI2 on platelet aggregation and disaggregation in whole human blood was studied at 37 °C in vitro. Aggregation or disaggregation was quantified by counting single platelets using the recently developed Ultra Flo 100 Whole Blood Platelet Counter. Aggregation of platelets in whole blood was induced by arachidonic acid (AA, 400 μM), adenosine 5’-diphosphate (ADP, 10 μM), thrombin (0.1 U/ml) and collagen (1 μg/ml). At peak aggregation, each aggregating agent induced about a 90% fall in the number of single platelets counted. When whole blood was pre-incubated with PGI2 (0.5–8 nM), it dose dependently inhibited aggregation of platelets induced by all four aggregating agents. Platelet aggregates induced by ADP or thrombin could rapidly be disaggregated by PGI2 added to blood at peak aggregation. Disaggregation of collagen-induced platelet aggregation by PGI2 was slow and minimal and it was completely ineffective in disaggregating AA-induced platelet aggregates. Unlike platelet-rich plasma, which is routinely used to study platelet aggregation, the present whole-blood method allows red and white blood cells to exert their influences on platelet function, and is an important step towards a physiological state for evaluating the effects of pharmacological agents on platelets in whole blood in vitro and

ISSN:1424-8832    

DOI:10.1159/000215110

出版商:S. Karger AG    

年代:1984

数据来源: Karger

摘要:

The present study was designed to clarify the reason why rat platelets obtained from arterial blood show a less marked aggregation than those obtained from venous blood, and to investigate the contribution of the vessel wall to this phenomenon. Incubation of arterial or venous platelet-rich plasma (PRP) with papaverine, a phosphodiesterase blocker, resulted in a more marked inhibition of the aggregation parameters for arterial than for venous PRP, indicating that a cAMP-dependent mechanism is involved. Incubation of PRP in vitro with adenosine deaminase did not significantly modify aggregation. Rats treated in vivo with different doses of acetylsalicylic acid or of tranylcypromine, two cyclo-oxygenase inhibitors, abolished the aggregation differences between arterial and venous PRP. It is suggested that this difference in platelet behavior may be due to a mechanism dependent on a PGl2-like, probably cAMP-related activity in which the heart and/or the lungs may play an important role.

ISSN:1424-8832    

DOI:10.1159/000215111

出版商:S. Karger AG    

年代:1984

数据来源: Karger

摘要:

In order to measure megakaryocyte DNA content in a greater number of well-defined patients, the use of bone marrow aspirates obtained postmortem is a basic requirement. We could show that the distinction between the ploidy classes in DNA histograms is possible until 18 h postmortem. Thus, bone marrow aspirates obtained up to 12 h after death can be expected to give reliable results. Megakaryocytes of the following patient groups were studied: 15 patients with metastatic tumors and paraneoplastic thrombosis, 15 patients with metastatic tumors without paraneoplastic thrombosis and 10 controls. An increased ploidization of the megakaryocytes was found in all 30 patients with metastatic tumors, independently of whether these patients suffer from thrombosis or not. Higher megakaryocyte ploidization, however, is correlated with a larger cytoplasmic mass of megakaryocytes, which leads to an increased platelet production. Besides an overcompensation for increased platelet consumption, a mitogenic or thrombopoietin-like factor produced by the tumor itself must be considered.

ISSN:1424-8832    

DOI:10.1159/000215112

出版商:S. Karger AG    

年代:1984

数据来源: Karger

ISSN:1424-8832    

DOI:10.1159/000215113

出版商:S. Karger AG    

年代:1984

数据来源: Karger