Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

This study aimed to determine the kinetics of albumin resorption from and the healing of two types of albumin impregnated Vasculour II (Bard Cardiovascular) Dacron grafts (ACG-A and ACG-B) using whole blood preclotted Vasculour II Dacron grafts (without albumin) as controls (PCC). Prostheses measuring 4 mm ID x 50 mm length were implanted in the aortoiliac position in 24 dogs (ACG-A n = 12, ACG-B n = 24, PCC n = 12) and explanted after 1, 2 4, and 6 months. Platelet count, platelet aggregometry to 10(-5) M ADP, prothrombin time (PT), and partial thromboplastin time (PTT) were determined preoperatively and at explantation. Sections of the explanted grafts were assayed for human albumin by immunohistochemical techniques utilizing a rabbit polyclonal mono-specific antibody for human albumin followed by the addition of a biotinylated goat anti-rabbit IgG. Immunoperoxidase staining was then performed using Avidin D horse-radish peroxidase. Histology of the grafts (light microscopy, scanning electron microscopy, and transmission electron microscopy) as well as percent thrombus free surface area (TFSA) by computerized planimetry were also determined. Seven of 48 grafts were occluded (85.4% patency) with no difference among the three groups. Platelet aggregometry was not predictive of graft patency. No change in PT or PTT occurred nor was there any difference among the three groups. Retained albumin was detected in every one-month explant but not beyond that time, with the sensitivity for detecting human albumin in this assay being 20 mg albumin per gram of Dacron. All ACG explants at one month revealed inner capsular fibrin coagula not present in PCC specimens.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Albumin impregnated vascular grafts: albumin resorption and tissue reactions. 138 74

The purpose of this study was to determine whether normal fibrinogen contributes to the development of myocardial reperfusion injury by acting as a substrate in vivo for neutrophil adhesion. This was tested in a dog model of acute myocardial infarction that used pentobarbital anesthetized dogs subjected to 90 min regional myocardial ischemia and 5 h reperfusion. Dogs were treated with 1 unit/kg Ancrod (venom from the Malayan pit viper, Agkistrodon rhodostoma) or vehicle i.v. 60 min after left circumflex coronary artery occlusion. Therapeutic defibrination was verified in Ancrod-treated dogs by measurements of clottable fibrinogen, alpha-2 antiplasmin and plasminogen, by the activated partial thromboplastin time and by immunoelectrophoresis. Fibrinogen was depleted to below detectable limits of the assay (less than 0.05 mg/ml) after treatment with Ancrod. The defibrination effect was accomplished by the expected activation of the fibrinolytic system: alpha-2 antiplasmin was decreased by 10% and plasminogen activity was decreased by 30% with Ancrod treatment. There were no measureable differences between the two treatment groups in heart rate, mean arterial blood pressure, rate pressure product or circumflex coronary blood flow throughout the 90 min of regional ischemia or during the 5 h of reperfusion. The relative severity of ischemia between the two treatment groups was similar when assessed with radiolabeled microsphere measurement of myocardial blood flow. The accumulation of neutrophils (measured by myeloperoxidase activity) within the myocardium after reperfusion was not reduced by prior depletion of fibrinogen.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Therapeutic defibrination with ancrod does not protect canine myocardium from reperfusion injury. 170 37

By monitoring the activation of protein C and the regulation of factor Xa-catalyzed thrombin formation by the activated protein C (APC) on the surface of human umbilical vein endothelial cells (HUVEC), we found that functional protein C was synthesized in cultured HUVEC and expressed thereon in the presence of vitamin K. Furthermore, without exogenously added protein S, time-dependent and saturable accumulation of APC (20 fmol APC/10(5) cells) on the surface of HUVEC was observed. During prothrombin activation by the complex of membrane-bound factor Xa and endogenous factor Va formed on the surface of HUVEC, APC was generated, and the rate of thrombin formation decreased. Treatment of HUVEC with an antibody that inhibits the APC-catalyzed inactivation of endogenous factor Va clearly quenched the activity of surface-associated APC. Immunostaining of HUVEC with a horseradish peroxidase (HRP)-conjugated antibody that solely recognizes human protein C confirmed the presence of protein C on the surface of HUVEC. Northern blot analysis revealed that an about 1.8 kb mRNA species derived from HUVEC was hybridized with 32P-labeled protein C cDNA, as in the case of those from HepG2, which are known to synthesize normal protein C. The increase in the amount of protein C mRNA in HUVEC in parallel with cell growth provided supporting evidence for the synthesis of protein C during the culture of HUVEC. These results indicate that blood coagulation is regulated by endogenously generated and activated protein C, together with or without protein S, through inactivation of factor Va on the surface of endothelial cells.
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PMID:Synthesis of protein C in human umbilical vein endothelial cells. 171 50

In Japanese black cattle with large and long-existing hematomas, platelets was impaired in collagen aggregation function in vitro. There was no statistically significant difference from control animals in the tests of PT (prothrombin time) and PTT (partial thromboplastin time) for extrinsic and intrinsic blood coagulation system. Aside from impaired collagen aggregation function, platelets in the hematoma cattle showed the similar aggregation patterns as the normal cattle, when ADP, serotonin (5-HT), thrombin, arachidonic acid, epinephrine and ristocetin were used as agents for inducing aggregation. Decreased aggregation function as well as impaired collagen-induced release response in platelets suggested the hematoma cattle to be of storage pool disease (SPD). The impaired platelet was postulated to be a main cause of the large and long-existing hematomas. All of the hematoma cattle with impaired platelet functions had the eosinophils in peripheral blood of which granules were fewer and larger than normal ones. These large eosinophil granules were peroxidase positive and periodic acid Schiff (PAS) staining negative as typical eosinophil granules.
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PMID:Persistent hematomas in Japanese black cattle with impaired platelet aggregation function and large granule eosinophils. 183 Jul 60

This study describes a process by which serine proteases that contain an S-1 arginine subsite and active site histidine may be inactivated and subsequently quantitated using a combination of peptidyl chloromethylketone chemistry and immune recognition technology. Active site labeling and inactivation of proteases is attained by modification of the active site histidine with a peptidyl chloromethylketone. In the specific illustrations demonstrated, we used the compound biotinyl-epsilon-aminocaproyl-phenylalanylprolylarginyl chloromethylketone. This reagent reacts quantitatively and specifically with the active site histidine of a wide variety of proteases that are elaborated in the coagulation and fibrinolytic system. The inactivated enzyme(s) may be quantitated by combinations of antiprotein antibodies and avidin binding technology using the biotin moiety on the peptide inhibitor. We have demonstrated the capability of capture of inactivated enzyme products directly on to solid-phase avidin with subsequent quantitation of bound protein using specific antibodies. In the converse system we have captured specific proteases using antiprotein antibodies in the solid phase and have quantitated bound enzyme by using avidin. Subsequent detection and quantitation has been achieved using the enzymatic activity of horseradish peroxidase conjugated either to the antibody or to avidin. Both types of assays are feasible, with avidin capture being the preferred mode when enzyme is evaluated in the presence of excess zymogen, as would be common in the evaluation of most blood-clotting enzymes. Assays are illustrated for tissue plasminogen activator, plasmin, thrombin, factor Xa, and activated protein C, which can measure protease concentrations as low as 50 pmol/L. Specific applications of the assays are provided in studies of the activation of prothrombin by the prothrombinase complex and of factor X with Russell's viper venom factor X activator. These assays measure the mass of active site present in the reaction mixture and are relatively independent of subspecies of enzyme or the environment in which the activity is generated. These assay systems provide powerful tools for elucidating product-precursor relationships in multienzyme feedback reactions involving zymogen activation.
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PMID:Active site-specific immunoassays. 211 28

The solid-phase clotting assay utilizing fibrinogen coated on the wells of a microtiter plate and peroxidase-fibrinogen in solution as a substrate for thrombin (enzyme-linked coagulation assay, ELCA) has been modified for use as an immunoassay. Direct inhibition of factors II, VII, and X by polyclonal (rabbit) antibodies and of factor X by monoclonal antibodies has been demonstrated at high dilution of these antibodies and detection of the specific factors using ELCA. Using plates coated with a second antibody (goat anti-mouse IgG) as well as fibrinogen, monoclonal antibodies to factors X and VII were measured by binding the active factor to the plate and detection of the bound factor using ELCA. The assay was very sensitive, permitting the detection of as little as 0.2 ng/ml (30 pg/assay) of monoclonal antibody, or less than 0.4 ng/ml (60 pg/assay) of factor Xa. When plates were coated with monoclonal antibody to factor X and fibrinogen, the assay permitted the identification of distinct epitope specificities for two monoclonal antibodies to factor X by distinct competition of the monoclonal antibodies added in the solution phase for binding of factor Xa to the plate. This assay could be applied generally for immunoassay of clotting factors, and could have application in general as an immunoassay amplification system.
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PMID:Enzyme-linked coagulation assay. III. Sensitive immunoassays for clotting factors II, VII, and X. 244 Mar 38

We reported a rare case of triple cancers with acute lymphoblastic leukemia (ALL) associated with disseminated intravascular coagulopathy (DIC) after the operations of colon cancer and primary lung cancer. A 78-year-old Japanese male, who had been operated upon for colon cancer (adenocarcinoma) on March 1981, metastatic brain tumor (adenocarcinoma) on December 1986, and primary lung cancer (squamous cell carcinoma) on February 1987, was admitted to our hospital because of severe general malaise on December 6 1987. On admission, he had mild hepatosplenomegaly and hemorrhage diathesis such as purpura. Serum LDH increased to 2,515 mU/ml. The white blood cell count was 6,210/microliters with 53% leukemia cells, and the platelet count was 12,000/microliters. A bone marrow was infiltrated with 96.0% leukemia cells. The leukemia cells stained positively for PAS and negatively for peroxidase. Immunological examination of leukemia cells showed that HLA-DR, TdT, B1 and J5 were positive and cytoplasmic Igmu and surface Ig were negative, indicating common ALL. The coagulation studies revealed that the activated partial thromboplastin time was prolonged to 42.0 seconds, FDP increased to 79.9 micrograms/ml, and antithrombin-III decreased to 62%. Chromosome analysis showed a 48, XY, +2, +21q-, t(9;22) karyotype. He was diagnosed as having Ph1 positive ALL associated with DIC. He was treated with vindesine, prednisolone, L-asparaginase, and adriamycin and complete remission (CR) was achieved after two months. But on August 1988, 8 months after CR, ALL and brain tumor relapsed and he died of pneumonia on September 19, 1988.
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PMID:[Ph1 positive acute lymphoblastic leukemia with DIC after operation of colon and lung cancer]. 281 Jul 93

We have developed a solid-phase clotting assay which uses peroxidase-fibrinogen in solution and fibrinogen bound to microtiter plates as a substrate for the thrombin generated from the clotting cascade. We have developed this assay for measurement of the extrinsic pathway factors thromboplastin (tissue factor, factor III), VII and VIIa, X, and II. Using long incubation times (40-90 min), thromboplastin could be measured in extracts of human brain at very low concentrations. Specificity for thromboplastin was demonstrated by showing a requirement for factors II, V, X, and VII but not for VIII, IX, XI, or XII; both substrate plasmas monodeficient in single factors and mixtures of the pure factors were used in demonstrating this specificity. The assay was modified to measure factors II, VII, VIIa, and X using appropriate deficient plasmas. The limit of detection was 2-3 orders of magnitude lower than a one-stage clotting test for all factors assayed. This assay has the advantages of convenience, specificity comparable to standard clotting tests, and high sensitivity.
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PMID:Enzyme-linked coagulation assay. II. A sensitive assay for tissue factor and factors II, VII, and X. 300 42

Human factor VIII was purified from commercial factor VIII concentrate with a 12% yield. The specific coagulant activity of purified factor VIII was 8,000 units/mg. In the presence of SDS the purified factor VIII consisted of a variety of polypeptides on polyacrylamide gels, ranging between Mr 80,000 and Mr 208,000. In the absence of SDS the purified factor VIII showed an apparent molecular weight of 270,000 upon Sephadex G200 gel-filtration. The purified factor VIII could be activated by thrombin, which resulted in the disappearance of Mr 108,000-208,000 polypeptides in favor of an Mr 92,000 polypeptide. Treatment with factor Xa also activated factor VIII, whereas treatment with activated protein C resulted in the inactivation of coagulant activity. Coagulant-active 125I-factor VIII was prepared using a lactoperoxidase radioiodination procedure. This 125I-factor had the same characteristics as unlabeled factor VIII. All polypeptides could be precipitated with monoclonal antibodies directed against factor VIII. With 125I-factor VIII a pIapp of 5.7 was found in the presence of urea.
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PMID:Human factor VIII: purification from commercial factor VIII concentrate, characterization, identification and radiolabeling. 309 64

The pathogenesis of experimental adrenal hemorrhagic necrosis produced by acrylonitrile in the rat was investigated by various morphologic, biochemical, and pharmacologic methods. One dose of this chemical injected intravenously caused 100 per cent incidence of adrenal hemorrhage and necrosis in 90 to 120 minutes. Electron microscopy, histochemistry, and light microscopy combined with colloidal carbon labeling suggested an early damage (30 minutes after administration of acrylonitrile) to the vascular endothelium in the adrenal cortex, prominent at 60 minutes, when lesion to the parenchymal cells was not visible. The use of extracellular diffusion tracer horseradish peroxidase further indicated that parenchymal cell injury was a late event. Damage to the vascular endothelium in the adrenal cortex was associated with retrograde embolization of medullary cells and cell fragments into the cortical capillaries. The ultrastructurally demonstrated platelet aggregation and fibrin precipitation at the sites of discontinuous vascular endothelium were accompanied by a decrease in circulating platelets and fibrinogen as well as prolongation of prothrombin, partial thromboplastin, and thrombin time. The concentration of dopamine, unlike that of noradrenaline, in the adrenals but not in the brain of rats injected with acrylonitrile showed a time-dependent elevation. Pretreatment with phenoxybenzamine (alpha-adrenergic antagonist) or labetalol (alpha- and beta-adrenergic blocker) or metyrapone (11-beta-hydroxylase inhibitor) and the depletion of catecholamines by reserpine or prior medullectomy prevented the chemically induced adrenal necrosis. These results indicate that the presence of a functional adrenal cortex is necessary for the development of cortical damage which is associated with early vascular lesion caused and/or modulated by vasoactive amines from the medulla and/or (metabolites of) acrylonitrile.
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PMID:Pathogenesis of experimental adrenal hemorrhagic necrosis ("apoplexy"): ultrastructural, biochemical, neuropharmacologic, and blood coagulation studies with acrylonitrile in the rat. 610 78


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