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

Evidence of developmental evolution of coagulation can be seen when the studies of 10 thriving extremely premature (EPT) infants are compared to normal full-term (FT) infants. The prothrombin time, partial thromboplastin time, and thrombin time all became shorter with increasing gestational age. Fibrinogen levels and platelet counts appear to be comparable to term infant and adult levels. Fibrin degradation products (FDP) of 10 micrograms/ml or less were found in the thriving EPT infants. When compared to healthy full-term infants, there is a definite gestational dependency of anti-thrombin III levels. Factors II and VII appear to be related to intrauterine maturation after the age of viability (24 wk), but factor VII-X complex does not. The contact factors XI, XII, high molecular weight kininogen (Fitzgerald factor), and prekallikrein (Fletcher factor) are all markedly decreased in thriving EPT infants. The mean factor V level is lower than that found in FT infants. This study confirms a gestational age dependency of factor VIII activity. The ratio of factor VIII antigen to factor VIII clotting activity is increased (2.8 vs 1.01 in FT and adults). Thriving small for gestational age (SGA) infants had coagulation studies which were not statistically different from those of thriving EPT infants. The coagulation changes which occurred in severely ill EPT were mainly in the factors which decrease during intravascular coagulation (factors I, V, and VIII). The present study suggests that because of the high antigen to activity ratio seen in thriving EPT infants, a dysfunctional or fetal factor VIII may have been produced. However, the further elevation of this ratio in the severely ill EPT infants is in keeping with a pathologic proteolysis or increased endothelial release of factor VIII antigen.
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PMID:Coagulation studies in extremely premature infants. 52 93

Ontogeny of selected hemostatic system components was studied in 120 bovine fetuses which had been divided into eight monthly gestational age groups. Fetal blood was subjected to the following tests: platelet count, partial thromboplastin time, prothrombin time, thrombin time, fibrinogen quantitation, and assays for prothrombin and factors V and VIII. Platelet numbers corresponding to adult numbers were in fetal blood at least as early as gestation day 60, and their numbers varied only slightly thereafter. Bovine blood was incapable of in vitro coagulation at gestation day 90, with all samples coagulating by gestation day 150. Fetal coagulation screening test times (partial thromboplastin time, prothrombin time, and thrombin time) shortened during gestation and were near times of adults at birth. Of the four individual coagulation factors tested, only factor VIII reached adult values in the fetus in utero. Amounts of fibrinogen, prothrombin, and factors V and VIII in the neonate exceeded that of normal adult cattle.
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PMID:Ontogeny of bovine hemostasis. 52 61

The Coag-a-Pet Dual Channel is an instrument which automatically records coagulation test end-points utilizing a photo-optical clot detection system. The instrument and its operation are described in detail. The capability of the instrument to perform tests of oral anticoagulant control, basic coagulation profiles and one-stage factor assays is assessed. In terms of precision and accuracy, the instrument performs well in carrying out the one-stage prothrombin time, Thrombotest, activated partial thromboplastin time using an automated APTT reagent but not kaolin, and one-stage factor assays. The thrombin clotting time can not be measured on this instrument. The instrument is most suitable for batched repetitive tests, reducing observer error and improving laboratory efficiency.
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PMID:Assessment of the Coag-a-Pet Dual Channel in the routine haemostatic laboratory. 53 9

Lysosomes (granules) of rabbit PMN leukocytes were extracted with either HCl or H2SO4, and the extracts were chromatographed over Sephadex to separate protein constituents. Some of the low molecular weight cationic proteins homogeneous on SDS PAGE (8% and 12.5% gels) were characterized by electrophoretic mobility in acid gels and by amino acid analysis. A 3,700 dalton polypeptide, rich in arginine and cysteine, prolonged the partial thromboplastin time of normal plasma. In low concentration, this protein shortened the clotting time of pure fibrinogen by thrombin. In high concentration this lysosomal cationic protein precipitated fibrinogen from solution; no fibrinopeptides were released to suggest cleavage of fibrinogen. Fibrinolytic protease activity was detected in crude H2SO4 extracts but not in crude HCl extracts. Two separate plasminogen activators, differing from kallikrein or prekallikrein, were isolated from the H2SO4 lysosomal extract and were partially characterized; neither exhibited proteolytic activity on fibrinogen free of plasminogen.
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PMID:Isolation and characterization of granulocyte lysosomal proteins and study of their effects on the clotting system. 54 40

The anticoagulant activity of the triiodinated X-ray opaque media iodipamide, iothalamate and diatrizoate on standardized normal human pool plasma was investigated in vitro. We found a dose dependent lengthening of the thrombin time, the reptilase time and the partial thromboplastin time together with a dose dependent drop of the calcium thromboplastin and factor V activity. Iodipamide proved to exert the most pronounced anticoagulant activity of the 3 contrast media tested. The results are interpreted as latent disseminated intravascular coagulation with hyperfibrinolysis following the direct interaction of contrast media with the coagulation enzymes.
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PMID:[Anticoagulant activity of triiodinated x-ray opaque media (author's transl)]. 57 82

The medical records of 118 cases who met laboratory criteria of DIC were studied. The most frequent etiologies were: Generalized infection (39.8%), trauma (16.9%), malignancy (6.8%) and surgical cases (6.8%). The main clinical manifestations which appeared to be related solely to DIC were (in a decreasing order of frequency): Bleeding (64.4%), renal dysfunction (24.6%), liver dysfunction (18.6%), respiratory dysfunction (16.1%), shock (14.4%), thromboembolic phenonmena (6.8%) and central nervous system involvement (1.7%). In 26 patients none of these manifestations were observed. In patients with infection, liver and renal dysfunction were frequent and respiratory dysfunction rare, whereas in trauma cases, liver and renal dysfunctions were rare and respiratory dysfunction frequent. This variability indicates that the clinical manifestations are affected not only by the process of intravascular coagulation but also by the underlying clinical disorders. The most impaired coagulation tests were prothrombin time, partial thromboplastin time, platelet count and thrombin time. The degree of abnormality of these coagulation tests was found to be related to the extensiveness of organ involvement. The mortality (overall 54.7%) increased independently with age, with the number of clinical manifestations and with the degree of abnormality of the above-mentioned four most impaired coagulation tests. In addition, older patients were more likely to have an increased number of clinical manifestations and more impaired coagulation tests. Mortality was similar in the various etiologies except for trauma patients in whom it was lower (30%).
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PMID:Clinical and laboratory aspects of disseminated intravascular coagulation (DIC): a study of 118 cases. 58 Apr 88

An improved method for the preparation of bovine alpha-thrombin is described. The procedure involves that activation of partially purified prothrombin with tissue thromboplastin followed by chromatography on Sulfopropyl-Sephadex C-50. The purified enzyme is homogeneous on polyacrylamide discontinuous gel electrophoresis and has a specific activity toward fibrinogen of 2.200-2,700 N.I.H. U/mg. Its stability on storage in liquid media is dependent on both ionic strength and temperature. Increasing ionic strength and decreasing temperature result in optimal stability. The denaturation of alpha-thrombin by guanidine hydrochloride was found to be a partially reversible process with the renatured species possessing properties similar to "aged" thrombin. In addition, the catalytic properties of alpha-thrombin covalently attached to agarose gel beads were also examined. The activity of the immobilized enzyme toward fibrinogen was affected to a much greater extent than was the hydrolysis of low molecular weight, synthetic substrates.
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PMID:On the preparation of bovine alpha-thrombin. 58 Apr 93

Twenty peptide-4-methylcoumarin amides (MCA) were newly synthesized and tested as possible substrates for alpha-thrombin, factor Xa, kallikreins, urokinase, and plasmin. These fluorogenic peptides contained arginine-MCA as the carboxyl-terminus. Release of 7-amino-4-methylcoumarin was determined fluorometrically. Of these peptides, the following were found to be specific substrates for individual enzymes: Boc-Val-Pro-Arg-MCA for alpha-thrombin, Boc-Ile-Glu-Gly-Arg-MCA, and Boc-Ser-Gly-Arg-MCA for factor Xa, Z-Phe-Arg-MCA for plasma kallikrein, Pro-Phe-Arg-MCA for pancreatic and urinary kallikreins, and glutaryl-Gly-Arg-MCA for urokinase. Moreover, these peptide-MCA substrates were resistant to plasmin.
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PMID:New fluorogenic substrates for alpha-thrombin, factor Xa, kallikreins, and urokinase. 59 14

In 12 vascular and 17 trauma cases the changes in the coagulation system due to intraoperative autotransfusion (IAT) were examined immediately after the IAT as well as 24, 48, 72 h and one week later. The following parameters were monitored: 1. Platelet count. --2. Prothrombin-time, partial-thromboplastin-time, factors II, V, VII, X and thrombin-clotting-time. --3. Fibrinogen, alpha-1-antitrypsin, alpha-2-macroglobulin, antithrombin III and plasminogen in 5 trauma cases. --4. Euglobulin-Lysis-Time. --After the IAT a loss of platelets, factors I, II, V, X, plasminogen and antithrombin III was found. Alpha-1-antitrypsin and alpha-2-macroglobulin remained unchanged or showed a slight increase. 24 h after treatment with Ugurol and heparin, fresh frozen plasma, fibrinogen and Cohn I-fraction in selected cases, an increasing normalisation of most parameters was seen, except for the plasma proteins active in coagulation. They showed a combination of "consumption coagulophathy" and "hyperfibrinolysis" up to the 7th day. Under treatment outlines above even marked laboratory changes remained without any clinical significance. Thus our results confirm that IAT does not cause any additional irreversible damage to the coagulation system. Therefore IAT can be considered as method of choice for the emergency treatment of massive bleeding.
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PMID:[Intraoperative autotransfusion and its influence on the blood-clotting-system (author's transl)]. 59 9

The results of this paper indicate that cattle infected with B. bovis (argentina) have a markedly altered and activated coagulation system. A degree of thrombin activation occurs due partly to release of thromboplastin-like substances from lysed erythrocytes but due primarily to activation of kallikrein by babesial proteases. This produces a hyperfibrinogenaemia, particularly in intact cattle, with soluble fibrin complexes constituting up to one-third of the total fibrinogen concentration. High molecular weight non-coagulable fibrinogen-like proteins are detected terminally but more so in splenectomized cattle. Plasminogen concentration decreases in splenectomized but not intact cattle while low molecular weight fibrinogen degradation products are not easily detected. It is suggested that a hypercoagulable intermediate state with little or no fibrin deposition occurs rather than terminal disseminated intravascular coagulation.
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PMID:Babesia bovis (argentina): observations of coagulation parameters, fibrinogen catabolism and fibrinolysis in intact and splenectomized cattle. 60 70


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