Showing papers in "Thrombosis and Haemostasis in 1983"
TL;DR: The exposed tissue thromboplastin activity on the surface of the endotoxin stimulated monocytes is probably the direct inducer of disseminated intravascular coagulation (DIC) in meningococcal infection.
Abstract: In 16 patients, 13 with meningococcal infection and 3 suspected to have this infection, 8 patients were found to possess significant higher level of tissue thromboplastin activity of their monocytes isolated from the blood at the admission to the hospital than normal. Five of those 8 patients had an extremely high concentration, greater than 60-300 fold increase, and all these patients died. The exposed tissue thromboplastin activity on the surface of the endotoxin stimulated monocytes is probably the direct inducer of disseminated intravascular coagulation (DIC) in meningococcal infection.
293 citations
TL;DR: The revised model, which retains fundamentally the same principle for standardising prothrombin time tests, has proved suitable for calibrating thromboplastins of different species and types and, moreover, has certain statistical advantages over its predecessor.
Abstract: Thromboplastins vary in their sensitivity to the haemostatic defect induced by oral anticoagulants. To provide a means of standardising prothrombin time tests, the World Health Organization adopted in 1977 a scheme for calibrating thromboplastins in terms of an International Reference Preparation. Unfortunately, the model on which this scheme was based does not always hold. A revised calibration model has therefore been developed and this has been tested in a recent collaborative study. The revised model, which retains fundamentally the same principle for standardising prothrombin time tests, has proved suitable for calibrating thromboplastins of different species and types and, moreover, has certain statistical advantages over its predecessor. In September 1982, the WHO Expert Committee on Biological Standardization adopted the revised model. This paper explains the nature and rationale of this change and considers its practical implications.
284 citations
TL;DR: It is concluded that a n-3 PUFA oil supplement to the western diet exerts an effect that generally is considered as beneficial in terms of the risk of developing cardiovascular diseases and in this respect superior to that of n-6 PUFA.
Abstract: Diverging results from studies of marine oil supplementation to western diets initiated the undertaking of a double-blind crossover study, with administration to healthy volunteers for 4 weeks of either 10 g of fish oil or 10 g of vegetable oil Each oil containing approx 40% of n-3 and n-6 polyunsaturated fatty acids (PUFA) respectively During the n-3 PUFA period, systolic blood pressure, plasma total lipids, triglycerides and VLDL concentrations fell significantly whereas plasma antithrombin-III (AT-III) rose Cutaneous bleeding time increased significantly In contrast only AT-III rose during the n-6 PUFA feeding, however, more marked than during the n-3 oil period It is concluded that a n-3 PUFA oil supplement to the western diet exerts an effect that generally is considered as beneficial in terms of the risk of developing cardiovascular diseases It is in this respect superior to that of n-6 PUFA, stressing the necessity of a more differentiated approach to advice on dietary PUFA enrichment than presently is exerted
221 citations
TL;DR: The results indicate that the reason for a defective post-occlusion fibrinolytic activity in a majority of cases may be the presence of increased concentrations of a fast-acting specific t-PA inhibitor.
Abstract: Utilizing the immunoglobulin fraction from a goat antiserum against human uterine tissue plasminogen activator, an enzyme-linked immunoassay for tissue-type plasminogen activator in human plasma has been developed. With the new method, the concentration of t-PA in normal human acidified plasma is found to be 4.0 +/- 1.8 (SD) ng/ml. It increases to 12 ng/ml after a tourniquet test, and to 14 ng/ml after strenuous physical exercise. In a group of patients with idiopathic thromboembolic disease, the resting t-PA concentration was 5 ng/ml and the post-occlusion value 16 ng/ml. Furthermore, the patients also exhibited a normal post-occlusion rise in the concentration of plasmin-alpha 2-antiplasmin complex. However, in 37% of the post-occlusion patient plasmas, virtually no increase in t-PA could be detected by a specific activity assay. The results indicate that the reason for a defective post-occlusion fibrinolytic activity in a majority of cases may be the presence of increased concentrations of a fast-acting specific t-PA inhibitor.
215 citations
TL;DR: High levels of crosslinked fibrin derivatives were found in 30/30 patients with disseminated intravascular coagulation and in the majority of patients having deep venous thrombosis or pulmonary embolism.
Abstract: We have prepared a monoclonal antibody which recognises an antigenic determinant on D-dimer, a specific fragment resulting from the degradation of crosslinked fibrin. This antibody has been used in the development of an enzyme-linked immunoassay for D dimer and related degradation products containing crosslinked gamma-gamma chains, to provide a simple assay of circulating crosslinked fibrin degradation products suitable for clinical use. Since these crosslinked fibrin degradation products are characteristic of fibrinolysis, as distinct from fibrinogenolysis, their measurement should aid in the diagnosis, evaluation and monitoring of thrombotic and thrombolytic states. In preliminary studies, low concentrations of crosslinked fibrin derivatives were detected in normal sera. High levels were found in 30/30 patients with disseminated intravascular coagulation and in the majority of patients having deep venous thrombosis or pulmonary embolism.
202 citations
188 citations
TL;DR: In a study of 272 patients with myocardial infarction the 68 who died within 1 year had significantly higher levels of factor VIIIR:Ag, factor VIII:C, fibrinogen, alpha 1 antitrypsin and alpha 2 macroglobulin than those who survived.
Abstract: In a study of 272 patients with myocardial infarction (MI) the 68 who died within 1 year had significantly higher levels of factor VIIIR:Ag, factor VIII:C, fibrinogen, alpha 1 antitrypsin and alpha 2 macroglobulin than those who survived. The mean white cell count (WCC) and peak creatine kinase (CK) were also significantly higher in those who died compared with the survivors. There was considerable intercorrelation between many of the haemostatic variables, WCC and CK as well as between many of the clinical predictors of outcome and the laboratory variables. The differences in haemostatic variables between those who died and those who survived may merely reflect the size of the infarct; alternatively, the haemostatic system may influence prognosis following an MI.
141 citations
TL;DR: It is demonstrated that dipyridamole impedes platelet aggregation in whole blood by an interaction with red blood cells, probably involving adenosine.
Abstract: Dipyridamole possesses antithrombotic properties in the animal and in man but it does not inhibit platelet aggregation in plasma. We evaluated the effect of dipyridamole ex vivo and in vitro on platelet aggregation induced by collagen and adenosine-5'-diphosphate (ADP) in human whole blood with an impedance aggregometer. Two hundred mg dipyridamole induced a significant inhibition of both ADP- and collagen-induced aggregation in human blood samples taken 2 hr after oral drug intake. Administration of the drug for four days, 400 mg/day, further increased the antiplatelet effect. A significant negative correlation was found between collagen-induced platelet aggregation in whole blood and dipyridamole levels in plasma (p less than 0.001). A statistically significant inhibition of both collagen (p less than 0.0025) and ADP-induced (p less than 0.005) platelet aggregation was also obtained by incubating whole blood in vitro for 2 min at 37 degrees C with dipyridamole (3.9 microM). No such effects were seen in platelet-rich plasma, even after enrichment with leukocytes. Low-dose adenosine enhanced in vitro inhibition in whole blood. Our results demonstrate that dipyridamole impedes platelet aggregation in whole blood by an interaction with red blood cells, probably involving adenosine.
134 citations
114 citations
TL;DR: Five of the 9 protein C deficient patients had severe thrombotic tendency characterized by recurrent deep venous thromBotic tendency, and further 7 family members with protein C deficiency were revealed, consistent with autosomal dominant inheritance.
Abstract: Protein C antigen was determined by Laurell rocket immunoelectrophoresis in 225 patients with a history of venous thrombosis. Among these patients two females with protein C deficiency were detected. Additional studies in the families of the protein C deficient patients revealed further 7 family members with protein C deficiency. In 8 not anticoagulated patients with protein C deficiency the protein C ranged from 36 to 62% (median: 45%). In one patient on oral anticoagulant treatment protein C antigen concentration was less than 10%, F II and FX were 65 and 50%, respectively. The pattern of inheritance was consistent with autosomal dominant inheritance. 5 of the 9 protein C deficient patients had severe thrombotic tendency characterized by recurrent deep venous thrombosis (n = 4), pulmonary embolism (n = 1), probable mesenteric vein thrombosis (n = 1) and superficial thrombophlebitis (n = 2). All protein C deficient patients without thrombosis were less than 17 years old.
82 citations
TL;DR: It is suggested that vitamin E administration could have a beneficial effect in patients suffering from arterial thromboembolic diseases.
Abstract: The effect of vitamin E administration on platelet function was evaluated in a group of normal, healthy volunteers. Platelet aggregation induced by collagen, ADP and epinephrine and platelet adhesion to collagen were measured at weekly intervals in 20 men and 27 women divided into 3 experimental groups of 12 individuals each and one control group of 5 men and 6 women. One experimental group was on a 6-week regimen of vitamin E in increasing dosages (400 I. U.--1,200 I. U.), the second group received aspirin, 300 mg every other day, and the third group was on a combination of vitamin E and aspirin. In the control group, platelet function was measured at weekly intervals. In women, vitamin E by itself produced a small but significant reduction of collagen-induced platelet aggregation. A similar trend was seen in men. However, the reduction never reached statistical significance. Adhesiveness to collagen was not affected by aspirin ingestion but showed a highly significant reduction in vitamin E and vitamin E + aspirin treated individuals. These results suggest that vitamin E administration could have a beneficial effect in patients suffering from arterial thromboembolic diseases.
TL;DR: The majority of Australian venoms were shown to be prothrombin activators with variable dependence on the presence of factor V phospholipid and calcium, but none of these venoms had strong thrombin like activity in contrast to the Crotalid venoms which were powerfully throm bin like.
Abstract: A systematic study was made of the action on the plasma coagulation system of 20 Australian and Papuan Elapid and Hydrophiid snake venoms and compared with 4 Crotalid venoms and 1 Viper. The majority of Australian venoms were shown to be prothrombin activators with variable dependence on the presence of factor V phospholipid and calcium. None of these venoms had strong thrombin like activity in contrast to the Crotalid venoms which were powerfully thrombin like. The Crotalid venoms were also strongly fibrinolytic unlike the Elapid venoms which showed no or minimal evidence of fibrinolytic activity. Four Elapid venoms and 2 Crotalid venoms showed anticoagulant activity which contained neither antithrombin nor fibrinogenolytic activity and may act upon the prothrombin complex.
TL;DR: Since aggregation and fibrinogen binding involving the glycoprotein IIb/IIIa complex are readily reversed by EDTA, and since Ca2+ is required for thrombospondin binding to activated platelets, there may be a third type of platelet-platelet adherence that is not disrupted byEDTA.
Abstract: The mechanisms involved in platelet deaggregation are unclear. Washed platelets from rabbits or humans aggregated by ADP can be deaggregated by EDTA or PGI2 if the release reaction has not occurred; during deaggregation 125I-fibrinogen dissociates from the platelets. Human platelets suspended in a medium without calcium undergo the release reaction during ADP-induced aggregation; EDTA, PGE1 or PGI2 do not deaggregate these platelets although EDTA displaces much of the 125I-fibrinogen that associates with them during aggregation. Rabbit platelets aggregated by low concentrations of release-inducing stimuli (sodium arachidonate, collagen or thrombin) can be deaggregated by EDTA, PGI2 or PGE1 and 125I-fibrinogen dissociates from them; with high concentrations of collagen or thrombin, deaggregation and dissociation of 125I-fibrinogen is slower. Human platelets that have undergone the release reaction in response to thrombin, collagen or a combination of sodium arachidonate and ADP are not readily deaggregated by EDTA or PGE1. Since aggregation and fibrinogen binding involving the glycoprotein IIb/IIIa complex are readily reversed by EDTA, and since Ca2+ is required for thrombospondin binding to activated platelets, there may be a third type of platelet-platelet adherence that is not disrupted by EDTA; this type of binding plays a greater role with human than with rabbit platelets.
TL;DR: It is suggested that low concentrations of verapamil inhibit epinephrine-induced aggregation by interacting with platelet alpha-adrenergic receptors, and that higher concentrations of both calcium-blocking agents inhibit platelet responses to other aggregating agents by preventing intracellular calcium mobilization.
Abstract: The effects of the calcium-entry blocking agent nifedipine on the activation of human platelets by various agonists has been studied and compared with verapamil. Like verapamil, nifedipine inhibited platelet aggregation and secretion caused by collagen, the second phase of ADP-induced aggregation, and aggregation caused by the ionophore A23187. Both agents inhibited the formation of TXB2 from endogenous arachidonate, whereas only nifedipine inhibited platelet aggregation and decreased TXB2 formation caused by exogenous arachidonate without inhibiting uptake. These results indicate that both calcium-blocking agents may be inhibiting the release of arachidonate in platelets by phospholipases, and that nifedipine also inhibits the formation and action of thromboxane A2 in platelets. Epinephrine-induced aggregation was inhibited by low concentrations of verapamil while nifedipine only inhibited aggregation by epinephrine at much higher concentrations. It is suggested that low concentrations of verapamil inhibit epinephrine-induced aggregation by interacting with platelet alpha-adrenergic receptors, and that higher concentrations of both calcium-blocking agents inhibit platelet responses to other aggregating agents by preventing intracellular calcium mobilization.
TL;DR: Five thromboplastins were calibrated against the WHO primary international reference preparation 67/40 and BCT/099, finding a linear relationship between the logarithms of the prothrombin times, measured in seconds.
Abstract: In a collaborative study of ten laboratories performed mainly within the framework of the BCR (the European Community Bureau of Reference), five thromboplastins were calibrated against the WHO (World Health Organisation) primary international reference preparation 67/40. Of these five thromboplastins, three were BCR reference materials (BCT/099, OBT/79 and RBT/79) and two were WHO secondary international reference preparations (68/434 and 70/178). Human brain tissue type is represented by 67/40 and BCT/099; bovine type by 68/434 and OBT/79, and rabbit type by 70/178 and RBT/79. The calibration relations are expressed in terms of a linear relationship between the logarithms of the prothrombin times, measured in seconds.
TL;DR: The PRP from the three species which aggregated with PAF also demonstrate the phenomenon of desensitization, whilst the response of human platelets is relatively independent of the Ca++ level above a certain threshold concentration.
Abstract: PAF-induced aggregation and dense granule release (ATP release) were investigated in human, primate, guinea pig, rabbit and rat platelet-rich plasma (PRP). Guinea pig PRP was most sensitive to PAF, followed by rabbit and then human. PRP from rats and primates did not aggregate or release when exposed to PAF. In guinea pig and rabbit PRP, release was independent of aggregatory response. In human PRP high doses of PAF (5 X 10(-7) M) caused maximum aggregation and a biphasic ATP release, whilst lower concentrations (3 X 10(-8) M) induced biphasic aggregation and one phase of ATP release concomitant with the second phase of aggregation. Aggregation and ATP release induced by PAF in guinea pig and rabbit PRP is dependent upon Ca++ levels, whilst the response of human platelets is relatively independent of the Ca++ level above a certain threshold concentration. The PRP from the three species which aggregated with PAF also demonstrate the phenomenon of desensitization.
TL;DR: The modulation by monosodium-urate crystals of PMN-endothelial interactions in vitro may have relevance to the understanding of the accelerated atherogenesis of hyperuricemia and the fulminant vasculitis of oxalosis or ethylene glycol poisoning.
Abstract: Immune triggered granulocyte (PMN)-endothelial interactions have been implicated in the pathogenesis of vascular diseases. While hyperuricemia and gout are associated with an increased risk of atherogenesis, we studied the modulation by monosodium-urate (MSU) crystals of PMN-endothelial interactions in vitro. The relationship between calcium oxalate (COX) crystals - implicated in the vasculitis of primary oxalosis - and immunologically mediated endothelial injury was also explored. Both MSU- and COX-crystal treated sera stimulate PMN to adhere to and induce significant 51Cr-release from endothelial cells in vitro. Platelets significantly increase crystal-triggered PMN endothelial cell adherence and 51Cr-release. This platelet augmenting effect depends on the release of platelet constituents (e.g. serotonin). Microcrystalline material present in vessel walls, thus may cause C-activation and may trigger PMN and platelets to damage endothelium in vitro and in vivo. These findings may have relevance to the understanding of the accelerated atherogenesis of hyperuricemia and the fulminant vasculitis of oxalosis or ethylene glycol poisoning.
TL;DR: The data show that in diabetes there is a depressed biological activity of antithrombin III and suggest that this reflects nonenzymatic glycosylation of antitrom bin III protein.
Abstract: Antithrombin III activity was moderately but significantly decreased in insulin dependent diabetics (p less than 0.005), while no difference has been found between the diabetic (n = 25) and control groups (n = 22) in antithrombin III plasma concentration. Moreover, antithrombin III activity was inversely correlated with glycosylated plasma proteins (r = 0.57; p less than 0.01). These data show that in diabetes there is a depressed biological activity of antithrombin III and suggest that this reflects nonenzymatic glycosylation of antithrombin III protein.
TL;DR: It is concluded that platelet shape change is at least in part triggered by changes in cellular Na+ and pH.
Abstract: The monovalent cation ionophores monensin and nigericin cause platelet shape change at a rate of approximately 1/20 of that caused by ADP. The effect of monensin was studied further. Shape change caused by monensin is pH dependent, increasing in rate as extracellular pH increases. Monensin induced shape change is not blocked by 30 microM cinanserin which completely inhibits serotonin induced shape change. Also, the amount of serotonin secreted by monensin treated platelets is below the threshold required to induce shape change. 100 microM ATP which inhibits ADP induced shape change does not affect monensin induced shape change. Amiloride, a sodium transport blocker, inhibits both the rate of ADP induced shape change and platelet spreading on poly-lysine coated glass. Amorphous platelet cytoskeletons isolated from resting platelets at pH 6.8 with Mg++ but not Ca++ can be transformed into filament bundles by subsequent incubation at pH 7.6. We conclude that platelet shape change is at least in part triggered by changes in cellular Na+ and pH.
TL;DR: It is concluded that neutral proteases possibly contribute to development of defects in platelet function in pathological states associated with liberation of leukocyte content into the circulation.
Abstract: Two highly purified neutral proteases from human leukocytes i.e. elastase-like protease (ELP) and chymotrypsin-like protease (CLP) do not destroy human platelets since no difference was found in 51Cr liberation from control and enzyme-treated platelets. As with pancreatic chymotrypsin (alpha-CT) ELP does not induce the release of 3H-serotonin while CLP provokes 3H-serotonin secretion, in an enzyme concentration and time dependent fashion. The rate and degree of 3H-serotonin release by CLP is similar to that produced by thrombin. Incubation of platelets at 37 degrees C for 30 min with alpha-CT or ELP renders them resistant to thrombin-releasing activity. Thrombin did not liberate any additional label from platelets which lost over 60% of serotonin during the preceding incubation with CLP. alpha-CT and ELP do not aggregate platelets either in the presence or absence of apyrase. CLP does aggregate platelets suspended in Tyrode buffer without apyrase but not in the presence of apyrase (100 mg/l). The action of alpha-CT, ELP and CLP on washed platelets induces a progressive prolongation of lag phase and a decrease in changes of light transmission during aggregation by thrombin. Similarly to alpha-CT-treated platelets, those subjected to CLP action aggregate in the presence of human fibrinogen. It is concluded that: (1) neutral proteases possibly contribute to development of defects in platelet function in pathological states associated with liberation of leukocyte content into the circulation, (2) CLP similarly to alpha-CT, exposes fibrinogen receptors but in contrast to alpha-CT, CLP aggregates platelets and stimulates serotonin secretion.
TL;DR: The relevance of the long half life of factor XIII to the prophylactic treatment of patients with inherited deficiency is demonstrated and an explantation for this finding is offered.
Abstract: Following the injection of a large dose of factor XIII concentrate the in vivo half life of factor XIII was estimated in a patient with inherited deficiency. Factor XIII activity and enzyme concentration were measured quantitatively, and a qualitative assessment of the crosslinking of fibrin was also made for upto 6 weeks after the injection. The half life was found to be about 9--10 days. This is longer than most previous reports suggest. An explantation for this finding is offered. The relevance of the long half life of factor XIII to the prophylactic treatment of patients with inherited deficiency is demonstrated.
TL;DR: It appeared that the effects of centrifugation parameters upon platelet yield depended upon the relative difference between platelet and red blood cell volumes.
Abstract: The effects of centrifugation force and time upon platelets function, mean platelet volume and platelet yield were compared with whole blood platelet counts and size in citrated blood samples from the bovine, canine, caprine, equine, feline, ovine and porcine species. The results were similar, for a given species, irregardless of sample volume. Bovine, caprine, feline and ovine platelet yields and mean platelet volumes were maximal when platelet-rich plasma was prepared using longer centrifugation times and lower gravitational forces. Canine, equine and porcine platelet yields and mean platelet volumes were maximal when platelet-rich plasma was prepared using shorter centrifugation times and higher gravitational forces. Platelet aggregation to adenosine diphosphate or arachidonic acid was not effected by the method of platelet-rich plasma preparation in bovine, caprine, feline, ovine or porcine platelets. Equine platelet aggregation was maximal when platelet-rich plasma was prepared using longer centrifugation times and lower gravitational forces. Canine platelet aggregation, particularly arachidonic acid-induced aggregation, was maximal when platelet-rich plasma was prepared using short centrifugation times and higher gravitational forces. It appeared that the effects of centrifugation parameters upon platelet yield depended upon the relative difference between platelet and red blood cell volumes.
TL;DR: Indirect evidence suggests that the alterations of the immune system began in 1979/80, with patients with severe classic hemophilia having a significantly reduced relative and absolute number of T-helper cells and a significantly increased relative andabsolute number ofT-suppressor cells.
Abstract: Various immunological parameters were determined in 46 patients with severe hemophilia A and in 9 patients with severe hemophilia B. All patients were treated over many years with commercial factor VIII or IX concentrates. Patients with severe classic hemophilia had a significantly reduced relative and absolute number of T-helper cells and a significantly increased relative and absolute number of T-suppressor cells. About half of these patients had an inverse T-helper/suppressor cell ratio. Patients with moderate hemophilia A and severe hemophilia B did not show these abnormalities. Hemophiliacs with an inverse ratio had a significantly higher concentration of serum total protein, IgG and IgM. No relationship between the amount of factor VIII concentrate administered, the HLA-type of the patient, the presence or absence of CMV-antibodies, hepatitis markers, thrombocytopenia and abnormal liver function tests to the T-cell abnormalities could be established. Lymphadenopathy was frequently associated with an inverse ratio. Indirect evidence suggests that the alterations of the immune system began in 1979/80.
TL;DR: It is suggested that increased blood and plasma viscosity may play a role in the vascular complications of the nephrotic syndrome.
Abstract: Blood viscosity and its major determinants (haematocrit, plasma viscosity and fibrinogen) as well as several haemostatic variables were measured in 21 patients with the nephrotic syndrome, and 21 controls matched for age, sex, smoking habit and serum creatinine. Blood viscosity was significantly increased in the nephrotic group, measured at a low shear rate (mean increase 41%, p less than 0.01) and at a high shear rate (mean increase 25%, p less than 0.01). Haematocrit was not significantly increased, but plasma viscosity was significantly higher (p less than 0.01), associated with increased plasma macroglobulins especially fibrinogen, which was increased to double the plasma concentration of the control group (p less than 0.01). Nephrotic subjects also had increased plasma levels of alpha 2-macroglobulin, factor VIII activity, factor VIII antigen and beta-thromboglobulin; differences in antithrombin III, fibrin degradation products, plasminogen, and platelet count were not significant. We suggest that increased blood and plasma viscosity may play a role in the vascular complications of the nephrotic syndrome.
TL;DR: The two PA types may be independently regulated in BEC since they were absent when the medium was conditioned in the presence of the protease inhibitor Trasylol.
Abstract: Confluent cultures of bovine aortic endothelial cells (BEC) were found to secrete both tissue type plasminogen activator (t-PA) and urokinase type plasminogen activator (u-PA). Exposure of the cultures to increasing concentrations of dexamethasone resulted in a time and concentration dependent inhibition of cellular and secreted u-PA. Complete inhibition of u-PA production and secretion was found at dexamethasone concentrations of 10(-8) molar or higher. Several distinct PA forms with molecular weights ranging from 10,000-20,000 to greater than 200,000 were found in the conditioned medium of untreated BEC cultures. After addition of dexamethasone (10(-7) molar) to the culture medium the PAs with molecular weights of 117,000, 58,000, 47,000, were absent suggesting that they were u-PAs, whereas the PAs with molecular weights of greater than 200,000 and 75,000 remained unchanged suggesting their t-PA origins. The PAs with lower molecular weights of 35,000, 28,000 and 10,000 to 20,000 were most likely generated from the higher molecular weight forms by limited proteolysis since they were absent when the medium was conditioned in the presence of the protease inhibitor Trasylol. The two PA types may therefore be independently regulated in BEC.