Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.6 (thromboplastin)
 13,278 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

After a simplified survey of the chemistry of phospholipids (PL) their presence in the lipid part of thromboplastin is dealt with, the significance of this structure being stressed. In addition, the condition, mode of action and synthesis of PL in blood platelets are extensively discussed and the impact of the composition of thrombocytic PL in the membrane and granular fraction by plasma lipid substances is referred to. The relations between single forms of PL and those proteins activating coagulation are represented and the conditions for the development of such activating complexes are referred to. Subsequently the coagulation stimulating properties of PL, thromboplastin, thrombocytes, and artifically produced PL are compared and the attempt is made to draw certain conclusions from sometimes contradictory results. Finally, the anticoagulative effect of phosphatidylserin is referred to.
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PMID:[Phospholipids and blood coagulation]. 8 81

Experimental infection of rhesus monkeys (Macaca mulatta) with Machupo virus produced a hemorrhagic disease similar to that of Bolivian hemorrhagic fever in humans. The disease in infected animals was also characterized by the development of hypotension and coagulation abnormalities as indicated by severe thrombocytopenia and prolongation of the activated partial thromboplastin time. Evidence for disseminated intravascular coagulation was inconclusive due to the presence of normal to elevated fibrinogen levels, relatively low levels of circulating fibrin split products, and the lack of widespread fibrin thrombus deposition. The most likely causes of the hemorrhagic tendencies of this disease in infected monkeys were thrombocytopenia and decreased synthesis of coagulation and other plasma proteins due to severe hepatocellular necrosis. Hypotension may also have been due to decreased plasma protein synthesis.
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PMID:Studies of the coagulation system and blood pressure during experimental Bolivian hemorrhagic fever in rhesus monkeys. 10 47

The adequacy of anticoagulation during 2 hours of cardiopulmonary bypass at 30 degrees C in 9 rhesus monkeys was determined by measuring the whole-blood activated clotting time (ACT) and by noting the appearance of thrombin-altered fibrin (fibrin monomer) and the relative consumption of clotting factors. Factor V and VIII, the heparin cofactor, antithrombin III, prothrombin time, partial thromboplastin time, ACT, platelets, hematocrit, fibrinogen, and fibrin monomer were determined prior to heparinization and after protamine. In 6 of 9 experiments, fibrin monomer became positive in the plasma during cardiopulmonary bypass (CPB), indicating that active coagulation was occurring. In 5 of the 6 animals, initial ACT was less than 400 seconds, and fibrin monomer appeared within the first 30 minutes of bypass. In 1 animal with an initial ACT of 439 seconds, fibrin monomer appeared after 60 minutes of bypass, at which time the ACT was less than 400 seconds. An abnormal level of fibrin monomer was not detected in 5 pediatric patients with an ACT greater than 450 seconds during CPB. Our experimental study and clinical data suggest that the lower limit, as measured by the ACT, for anticoagulant effect to provide coagulation-free CPB is at least 400 seconds.
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PMID:Adequate anticoagulation during cardiopulmonary bypass determined by activated clotting time and the appearance of fibrin monomer. 11 Feb 73

Clotting analysis in 30 patients with bleeding complications in malignant hematological diseases revealed the following troubles: The global tests, Quick's index and partial thromboplastin time markedly differed from normal. Activity of clotting factors revealed hypo- or hyperfibrinogenemia, disturbances of the prothrombin complex (factors II, VII, IX and X), decrease of factors V, VIII, XII. Factor XI (= PTA) was not diminished in any case. Regarding the fibrin-stabilizing factor (factor XIII), its activity was significantly decreased in 30 patients with solid tumors and in 30 patients with hemoblastoses. Faulty clotting balance was characterized by hyperfibrinolysis or disseminated intravascular coagulation (DIC) accompanied by reactive hyperfibrinolysis. About one quarter of the patients with malignant disturbances of the hematopoetic system demonstrated (mostly amegacaryocyte) thrombocytopenia. Finally, treatment of bleeding complications in malignant neoplastic diseases is pointed out.
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PMID:[Hemorrhagic diathesis in patients with malignant neoplasms (author's transl)]. 11 27

Anticoagulation has been reported to ameliorate antiglomerular basement membrane glomerulonephritis (anti-GBM-GN) while its effect on chronic immune complex glomerulonephritis (IC-GN) as studied in the NZB mouse is unclear. Chronic serum sickness IC-GN was induced in rabbits by injecting bovine serum albumin (BSA) daily. Anti-GBM-GN was induced by i.v. injection of a known amount of heterologous anti-GBM antibody. Heparin was administered beginning at two to six weeks after the first BSA injections or before the administration of anti-GBM antibody, on various schedules from 5000 U every 12 hr to 8000 U every 8 hr. With this dosage the partial thromboplastin time remained greater than 1-1/2 to 2-1/2 times the control at the time of the subsequent heparin injection. Heparinized and nonheparinized groups were matched according to duration of disease, maximum anti-BSA concentrations or anti-GBM antibody dosage--and no significant differences were found in proteinuria; severity of the glomerular histologic lesions; or immunofluorescence patterns of immunoglobulin G (IgG), third component of complement (C3), BSA or fibrinogen-related antigen(s) (FRA). Crescent formation was not prevented. This study shows that heparin in the maximum permissible dosage is ineffective in preventing glomerular FRA deposition or altering the progression of experimental IC-GN or anti-GBM-GN in rabbits.
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PMID:Failure of heparin to affect two types of experimental glomerulonephritis in rabbits. 12 30

Coagulation parameters were studied in rabbits during and after intravenous infusion of suspensions of dispersed fluorochemicals. Blood samples from rabbits given dispersed perfluorobutyltetrahydrofurane or perfluorotributylamine showed thrombocytopenia, prolongation of activated partial thromboplastin time, and decreases in Factors X and XI. The possible presence of an inhibitor of coagulation was suggested by the prolongation of prothrombin time when measured with serial dilutions of thromboplastin reagent. These abnormalities were not found in whole blood or platelet-rich plasma after incubation in vitro with dispersed fluorochemical.
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PMID:Coagulation defects in rabbits after infusion of dispersed fluorochemicals. 12 61

Frog muscles were shown to contain thromboplastin, antiheparin factor and activators of fibrinolysis. The thromboplastin activity was distinctly increased in exhausted muscles. At the same time the activity of fibrinolytic agents was increased less significantly. It was proposed that stimulation of cell structures was related to liberation of thromboplastin from membranes both into an extracellular environment and into the cell. The latter effect caused structural alteration in protoplasm, which resembled blood coagulation. The exhaustion is considered as a result of absence of suitable "spreading out" of protoplasm or as a process caused by decrease in content of structural biopolymers.
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PMID:[Activities of coagulation factor and fibrinolysin in muscles before and after exertion]. 12 93

Prekallikrein, plasminogen and prothrombin of human blood plasma have been separately activated by caolin streptokinase and thromboplastin. By measuring the TAME-esterase (N-d Tozy-L-arginine methyl ester) activity of each enzyme and its changes in the course of plasma incubation with the activator, it was possible to estimate the values of precursors of kallikrein, plasmin, thrombin and their inhibitors. Evidence is given that under conditions described the activation is specific of each enzyme and does not affect the level of the two other percursors. The method has been developed in two modifications, permitting to obtain the value of seven parameters in 0.4--0.7 ml of blood plasma.
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PMID:[Method of simultaneous determination of kallikrein, plasmin and thrombin precursors and inhibitors in human blood plasma]. 13 76

It was demonstrated in rat experiments that function inhibition of the anticoagulation system by means of intravenous injections of high doses of antiplasmin and aminasine resulted not only in certain changes in the blood coagulation parameters, but also in increased platelets aggregation. The appearance of increased quantities of free thrombin in the circulating blood may be one of the mechanisms favouring increased aggregation of platelets. The activation of the function of the anticoagulation system induced in experimental animals by intravenous injections of low doses of adrenalin, antiplasmin (12 U/200 g of body weight) and tissue thromboplastin results, along with hypocoagulation and enhanced enzymatic and non-enzymatic fibrinolysis, in a decreased platelets aggregation.
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PMID:[Thrombocyte aggregation in depression and activation of the anticoagulation system of blood in animals]. 13 13

Various endotoxins and the extracts of gram-positive bacteria were measured immunologically by radioimmunoassay and also biologically by the Limulus test. The minimum amount of endotoxin detectable with the Limulus test was in the range from 1ng/ml to 1 mug/ml, with the lysate of sensitivity, 100 ng/ml [E. coli O111: B4 (B) lipopolysaccharide]. On the other hand, by the radioimmunoassay they were estimated in the range o- 0.3 to 10 times of dry weight. Endotoxin-like activity was detected in the ether extracts of gram-positive bacteria at a minimum concentration between 1 mug/ml and 100 mug/ml with the Limulus test. However, most of them were estimated by the radioimmunoassay to be under 1/50 of dry weight. Various substances such as thrombin, thromboplastin, polyinosinic-polycytidylic acid, polyadenylic-polyuridylic acid, carrageenan and human colonic mucosal antigen had cross reactivities of various degrees in the minimum concentration from 10 mug/ml to 10 mg/ml. Compounds such as thrombin and thromboplastin cross-reacting in the Limulus test were scarcely measured by the radioimmunoassay except for polynucleotides. From this study, it has become clear that the radioimmunoassay method is quite specific and accurate for quantitative measurements of endotoxin.
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PMID:Measurement of endotoxin. II. Comparison of reactivities measured by radioimmunoassay and with the Limulus test. 13 53


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