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)

The clotting times obtained with different assay procedures for routine coagulation tests were examined for horse and pony samples. The whole blood clotting time test and the activated coagulation test seemed to give similar results when both tests were done at 22 C. The results obtained for the activated partial thromboplastin time assay varied, depending on the commercial reagent used for the test. Consistent results were obtained for the one-stage prothrombin time assay with each reagent used.
 ...
PMID:Comparative study of blood coagulation tests in the horse and pony. 62 70

Pertinent literature on naturally occurring hemorrhagic diseases in poultry and livestock were reviewed and compared with reports on recent outbreaks of a hemorrhagic syndrome in swine. Epizootiologic, clinical, and hematologic data from porcine hemorrhagic disease suggest vitamin K-responsive hypoprothrombinemia. In weanling pigs, the toxicity of warfarin was compared with that in swine given tylosin and sulfamethazine antibacterial combination versus those given warfarin only. Toxicosis was induced in weanling swine fed warfarin daily at dose level of 0.055 mg/kg of body weight. Approximately 5 days after feeding was started, signs of poisoning appeared: lameness, anorexia, subcutaneous hematomata, melena, and periarticular enlargement. Administration of warfarin at dose level of 0.017 mg/kg did not cause clinical toxicosis, and 0.028 mg/kg produced significant increases in one-stage prothrombin time (OSPT) and activated partial thromboplastin time (APTT), but no evidence of clinical bleeding. When tylosin-sulfamethazine antibacterial combination was fed at normal and high dose levels concurrently with warfarin at dose level of 0.017 mg/kg of body weight, increase of clotting time, OPST, or APTT did not occur due to antibacterial influence. The antibacterial combination fed alone did not produce changes in clotting time, OSPT, APTT, fibrinogen, total protein, differential leukocyte count, or packed cell volume.
 ...
PMID:Hemostatic function in swine as influenced by warfarin and an oral antibacterial combination. 64 99

Human brain is a common source of thromboplastin for the prothrombin time, where the end point is the conversion of fibrinogen to fibrin. Experiments showed that human brain also contains a proteolipid which inhibits the conversion of fibrinogen to fibrin. The proteolipid is removed when brain tissue is washed with acetone, but remains as a contaminant when brain is extracted with saline. For this reason prothrombin times on the same plasma are longer when saline extracts, rather than acetone dried preparations, are the source of thromboplastin. The proteolipid explains why the prothrombin time becomes shorter when saline extracts are diluted to standardize their activity against the British comparative thromboplastin.
 ...
PMID:An inhibitor of fibrin formation in thromboplastins prepared by saline extraction of human brain. 64 53

Acute consumptive coagulopathy may be initiated by diverse events. It is frequently necessary to establish the diagnosis with urgency. Rational therapy can only be approached with knowledge of the relative impact the primary consumption exerts upon hemostasis as well as the effects of secondary fibrinolysis. A constellation of interlocking tests within the capability of the small laboratory is presented. This includes the prothrombin time, the activated partial thromboplastin time, the serial thrombin time, the heat precipitation fibrinogen level, the platelet count, red cell morphology, the levels of fibrin (fibrinogen) degradation products and selected factor assays. This series can be completed within 45 minutes. Interpretation, with particular emphasis upon the stage in the natural history of the process when evaluation is instituted, and underlying diseases which modify typical patterns are discussed. The discriminant function of the serial thrombin time is stressed.
 ...
PMID:The seial thrombin time in the diagnosis of consumptive coagulopathy. 65 8

Plasma assay results for prothrombin time and activated partial thromboplastin time obtained on the fully automated Dade Auto-FI were compared with those obtained on the more traditional semi-automated Bio-Quest Fibrometer. The precision data showed in a majority of cases the superior reproducibility of the Auto-FI over the fibrometer. However, we found that results of APTT utilizing both methodologies were not at present interchangeable.
 ...
PMID:Comparison of prothrombin time and activated partial thromboplastin time on Dade Auto-FI and Bio-Quest Fibrometer. 66 97

By means of CM-Sephadex column chromatography, Trimeresurus mucrosquamatus venom was separated into 20 fractions. Fraction XX had the marked anticoagulant action. This fraction was refractionated three times on Sephadex G-75, and a single peak was obtained. The patterns of microzone and disc electrophoresis also showed a single band. A single, symmetrical boundary with a value of 1.61 S was obtained by ultracentrifugation. It was a single peptide chain with a molecular weight of 11 700. The isoelectric point was higher than pH 10. The anticoagulant principle possessed phospholipase A activity and was calcium ion dependent. It did not possess proteolytic, tosyl-L-arginine methyl ester esterase, phosphodiesterase and alkaline phosphomonoesterase activities of the crude venom. The phospholipase A activity was heat-labile at pH 7.4, but was heat-stable at pH 5.6. The anticoagulant activity was more resistant to heat treatment as compared with phospholipase A activity. The anitoagulant action of the purified principle was competitively inhibited by platelet phospholid, tissue thromboplastin and cephalin, and was neutralized by antiserum. The anticoagulant principle inhibited platelet aggregation induced by ADP. It did not destroy fibrinogen, Factor X, prothrombin and thrombin; nor did it induce fibrinolysis nor interfere with the interaction between thrombin and fibrinogen. It is concluded that the anticoagulant action of this phospholipase A was due to the inhibition of the activations of Factors X and II through the inactivation of the procoagulant activity of phospholipids mediated partly by phospholipid-binding activity of this venom enzyme and partly by its enzymatic hydrolysis of phospholipids.
 ...
PMID:Purification and characterization of the anticoagulant principle of Trimeresurus mucrosquamatus venom. 66 29

Aqueous extracts of thyroid glands were prepared from 25 surgical specimens of 19 patients. The average prothrombin time of sixteen 3:4 diluted extracts of thyroids from 13 euthyroid patients was 16.8 +/- 2.3 sec as measured with 100% human plasma. Under similar conditions the average prothrombin time of extracts obtained from the grey matter of three human brains was 18.4 +/- 0.3 sec. The thyroid may thus be considered as an organ containing one of the highest concentrations of tissue thromboplastin.
 ...
PMID:[Thromboplastin activity of extracts of human thyroid glands (author's transl)]. 68 25

The results of activated partial thromboplastin time (APTT) and prothrombin time (PT) determinations on the single-channel Coag-a-Mate, Coagulyzer Jr., Clotek, Electra 650, and Fibrometer instruments were compared with regard to precision, day-to-day reproducibility of results, and accuracy. There was no significant difference among the machines when PT was analyzed. In the APTT study, the single-channel Coag-a-Mate had the best overall precision (coefficient of variation 2 to 4%), while the Coag-a-Mate and the Electra 650 had the best day-to-day reproducibility (coefficient of variation 2 to 5%). The comparison study indicated good correlation (r greater than or equal to 0.95) between the reference instrument (Bio/Data CA-15) and the single-channel Coag-a-Mate, Electra 650, and Clotek. The correlation for the Coagulyzer Jr. was also quite good (r = 0.95), but it could not detect some of the clots detected by the other machines. The Fibrometer showed significantly poorer correlation (r = 0.87) when compared with the other instruments.
 ...
PMID:A comparison of five manually operated coagulation instruments. 69 74

The calcium-dependent interaction of vitamin K-dependent proteins with membranes is a complex process that minimally consists of 1) calcium binding to the protein and an essential calcium-dependent protein transition, 2) an essential calcium-membrane interaction, and 3) formation of the protein-membrane complex. Below about 5 mM calcium, the protein-membrane complex binds more calcium than the sum of the components but at higher concentrations protein-membrane binding is not accompanied by additional cation binding. These protein-menbrane interactions function in blood coagulation by increasing the binding affinity of the active site. The increased affinity results from the additive effects of protein-membrane (e.g., prothrombin-, factor Xa- and factor V-membrane) interactions and protein-protein (e.g., factor Xa- factor V and prothrombin-factor V) interactions. The prothrombinase complex can be viewed kinetically as a dissociable three-component enzyme (factor Xa, factor V, and phospholipid) acting on the soluble substrate, prothrombin.
 ...
PMID:Interactions of vitamin K-dependent proteins with calcium ions and phospholipid membranes. 70 Jan 72

The Coag A Pet 200 is an automatic clot-sensing instrument, with two channels; the variation in the optical density is detected by a photoelectric system. The results are sequentially printed out with the sample number. A critical evaluation of its performance in hospital use over 7 month, is reported. The series of tests thus automated consists of: one stage prothrombin-time, Owren test, activated partial thromboplastin time, analytical determinations of factors II, V, VII + X, VII, IX, XI, XII. The repeatibility is good: CV ranged between 0.5 to 1.5% or 2%, and a high degree of correlation with the standard manual techniques was found: R: 0.93 TO 0.99. This instrument was easy to master, use and maintain.
 ...
PMID:[Evaluation of an automatic clot-sensing instrument : Coag A Pet 200 (author's transl)]. 70 36


<< Previous 1 2 3 4 5 6 7 8 9 10