摘要:

The influence of sodium nitroprusside (SNP) and other nitric oxide complexes on platelet function is studied. SNP inhibits platelet aggregation and the release reaction, while pentacyanonitrosyl complexes of manganese, tungsten, and molybdenum are ineffective. Since nitrosylperchlorate exerts the same inhibitory effect on platelet aggregation the nitrosyl cation is supposed to be the constituent of SNP responsible for inhibition.

ISSN:1424-8832    

DOI:10.1159/000214063

出版商:S. Karger AG    

年代:1974

数据来源: Karger

摘要:

Platelet adhesion to glass, polyethylene, polyvinyl chloride, and Cuprophane has been studied by means of a method specific for quantitation of adhesion. Platelets adhered in larger numbers to polyethylene and polyvinyl chloride than to Cuprophane or glass regardless of the anticoagulant used. In citrated plasma, fewer platelets adhered to glass than to Cuprophane, although adhesion to glass and Cuprophane was nearly the same when EDTA or heparin was used as anticoagulant. The number of adherent platelets decreased appreciably from values obtained with citrated platelet-rich plasma, when EDTA or heparin was used as anticoagulant. Adhesiveness of normal platelets increased with age. A number of different pharmacologic and other agents were found to inhibit platelet adhesion to artificial surfaces. Acetylsalicylic acid and glucosamine were less effective inhibitors than sulfinpyrazone, imipramine, desipramine, amitriptyline, chlorpromazine, or PCMB. Penicillin did not inhibit adhesion. Donors deficient in factors VIII, XI, or XII or donors with von Willebrand’s disease showed normal platelet adhesiveness. Adhesiveness was markedly low in tests with blood from afibrinogenemic or thrombasthenic patients. Decreased adhesiveness of afibrinogenemic platelets could be corrected by addition of fibrinoge

ISSN:1424-8832    

DOI:10.1159/000214064

出版商:S. Karger AG    

年代:1974

数据来源: Karger

摘要:

The metabolic nucleotides of washed human platelets can be subdivided into ethanol-insoluble (almost all as ADP) and ethanol-soluble pools. About 5 % of the total radioactively labelled metabolic nucleotides are found in the ethanol-insoluble pool. At least part, if not all, of the ethanol-insoluble ADP is bound to platelet actomyosin (thrombosthenin). The specific activity of the ADP in this pool is the same as that of the rest of the metabolic ADP and is not ‘superactive’. Addition of thrombin to washed human platelets previously incubated with [3H]-adenine did not alter the level of ethanol-insoluble ADP, as compared to similarly treated control platelets. Similarly, there were no changes in the radioactive ADP content of actomyosin extracted directly from washed human platelets after exposure to thrombin, as compared to controls. The metabolic ADP content of control platelet actomyosin might reflect the in vivo situation, but the possibility exists that mechanical damage during platelet isolation from plasma and subsequent handling could have caused the exchange. No evidence presented here indicates the involvement of platelet actomyosin in the platelet release reaction mechan

ISSN:1424-8832    

DOI:10.1159/000214065

出版商:S. Karger AG    

年代:1974

数据来源: Karger

摘要:

In vitro granulocyte-platelet rosette formation (adherence of platelets to granulocytes) was noted as a cause of falsely low electronic platelet counts in two patients. Investigations showed that this phenomenon was caused by a plasma factor, contained in the IgG fraction; further, activity was completely inhibited with anti-IgG antiserum. Rosette formation could be detected with either autologous or isologous platelets and granulocytes. Moreover, repeated adsorptions of patients’ plasma with isologous platelets removed the rosetting facto

ISSN:1424-8832    

DOI:10.1159/000214066

出版商:S. Karger AG    

年代:1974

数据来源: Karger

摘要:

Platelets, lymphocytes, and megakaryocytes, specifically processed for the intracellular detection of antigens, were studied by indirect immunofluorescence techniques using monospecific antibodies directed against factor VIII-related antigen (F-VIII-RA). Specific staining was observed in platelets of the peripheral blood from normal individuals and from patients with haemophilia A, and in megakaryocytes and platelets of bone marrow from normal subjects. The same cells studied in patients with von Willebrand’s disease were negative. No bone marrow biopsies were performed on patients with haemophilia A. Our results indicate that F-VIII-RA is localized in megakaryocytes and platelets of normal subjects; the possible role of this F-VIII-RA in platelet function is discusse

ISSN:1424-8832    

DOI:10.1159/000214067

出版商:S. Karger AG    

年代:1974

数据来源: Karger

摘要:

For coagulation studies on rat blood requiring consecutive samples it is best to obtain blood from the tail, under ether anesthesia, by amputation of one vertebra for each sample wanted. Higher activity levels of clotting factors in unanesthetized rats are not due to stress. The coagulation activation phenomenon is always present in capillary blood samples from unanesthetized rats and is enhanced in serial blood samples unless three vertebrae are amputated to obtain the sample. The procedure described here, applied to unanesthetized rats, could serve as a model for the testing of antithrombotic drugs.

ISSN:1424-8832    

DOI:10.1159/000214068

出版商:S. Karger AG    

年代:1974

数据来源: Karger

摘要:

A study was conducted in seven males and eight females to determine the effect of feeding 25 and 35% fat calories on plasma lipids, blood clotting parameters and platelet aggregation. A statistically significant reduction in thrombin- and collagen-induced aggregation was observed at the end of the 25 %-fat-calorie period. At the end of the 35 %-fat-calorie period the thrombin- and collagen-induced aggregation tests rebounded to the predietary level. Platelet counts rose significantly and white blood cell counts decreased by the end of the 25 %-fat-calorie period. Both platelet counts and white blood cell counts returned to predietary levels at the end of the 35 %-fat-calorie period. Plasma cholesterol decreased an average 15% at the end of the 25 %-fat-calorie period and remained at the lowered level throughout the 35 %-fat-calorie period. It is suggested that levels of total and saturated fat in the diet are significant factors affecting the aggregation tendency of blood platelets.

ISSN:1424-8832    

DOI:10.1159/000214069

出版商:S. Karger AG    

年代:1974

数据来源: Karger

摘要:

In an attempt to examine the effect on hemostasis, 20 patients suffering from thrombophlebitis or from postthrombotic syndrome received 10,000 units of heparin and 1.5 g of acetylsalicylic acid (ASA) per day. The scheme of application permitted to distinguish three periods of treatment: heparin, heparin plus ASA and ASA alone. By frequent blood coagulation tests, the alterations of the clotting mechanism during each of these periods were examined. Influences on the plasmatic clotting mechanism were exclusively caused by heparin and were not altered by the addition of ASA. There was, however, a synergistic action of both drugs on the depression of platelet factor 3 availability. Platelet aggregation was enhanced by heparin but could be suppressed by the combined therapy as well as by ASA alone. The overall alterations of hemostasis and coagulation were mild. Even when both drugs were administered simultaneously, the changes were moderate and no clinical signs of hemorrhage could be detected. The purpose of this study was to examine whether a combination of both drugs can be safely applied in an attempt to increase the efficiency of preventive therapy of thromboembolism.

ISSN:1424-8832    

DOI:10.1159/000214070

出版商:S. Karger AG    

年代:1974

数据来源: Karger

摘要:

In three newborn infants exchange transfusions were performed with previously frozen red blood cells resuspended in a balanced albumin-saline solution or in fresh-frozen plasma. After the exchange a considerable decrease of platelets, fibrinogen, coagulation factors II, V, VIII and X and antithrombin III was noticed but no signs of increased bleeding tendencies. The restoration of the coagulation factors was more rapid when fresh-frozen plasma was used. For newborn infants with suspected or manifest coagulation disorders and for newborn infants needing more than one exchange transfusion, frozen, thawed and washed red blood cells should be resuspended in fresh or fresh-frozen plasma when used as transfusion blood.

ISSN:1424-8832    

DOI:10.1159/000214071

出版商:S. Karger AG    

年代:1974

数据来源: Karger

摘要:

The course of defibrination after administration of a thrombin-like snake venom protease, Defibrase®, has been studied in two patients with arterial occlusive disease. Agarose gel filtration of fresh plasma makes it possible to differentiate between high (HMWD) and low molecular weight fibrinogen and fibrin derivatives (LMWD) which arise during therapy. HMWD can be quickly and dependably detected in the column eluate by the staphylococcal clumping test. They probably consist mainly of fibrin monomer complexes during the coagulation phase, but during the fibrinolytic phase mainly of high molecular weight fibrinolytic degradation products. LMWD in the column eluates have been identified by radial immunodiffusion. By combining several different methods for the determination of fibrinogen-fibrin-related material the process of defibrination and reactive fibrinolysis may be studied in detail. The protracted activity of one injection of Defibrase can be clearly documented

ISSN:1424-8832    

DOI:10.1159/000214072

出版商:S. Karger AG    

年代:1974

数据来源: Karger