Plasma thrombin

In essence, the basic steps of making cell blocks consist of fixation, centrifugation to make cell pellet, transfer the pellet to a labeled tissue cassette which then is processed and embedded in paraffin. The most challenging component of this technique is the methods to harden the cell pellet so it can be easily picked up from the tube without losing precious material. With only a simple sedimentation technique, the cell pellet is usually small and friable. In order to harden the cell pellet, several technical modifications have been reported. The most popular methodology includes plasma-thrombin clot technique, agar technique, and fixation with Bouin s solution. 

Thrombin and fibrinogen are usually obtained from blood plasma. Thrombin (EC... 

Although there is much anecdotal evidence that TPN (as opposed to no nutrition) may be beneficial in hospitalized horses, this has not been proven (Lopes White 2002). The administration of TPN increases the risk of sepsis and thrombophlebitis in hospitalized human patients (loannides-Demos et al 1995). This may result, at least in part, from decreased intracellular killing by neutrophils (Okada et al 2000) and increased plasma thrombin-antithrombin III concentrations, which result in increased plasma coagulability (van der Poll et al 1998). 

Plasma thrombin time test 10 to 15 seconds Greater than 1 5 seconds... 

Antihemophilic factor [9001-28-9] (AHF) is a protein found in normal plasma that is necessary for clot formation. It is needed for transformation of prothrombin to thrombin. Administration of AHF by injection or infusion can temporarily correct the coagulation defect present in patients with hemophilia. Antihemophilic factor VIII (Alpha Therapeutic) has been approved by the FDA as replacement therapy in patients with hemophilia B to prevent bleeding episodes, and also during surgery to correct defective hemostasis (178). 

Thrombin (from bovine blood plasma) [9002-04-4] Mj 32,600 [EC 3.4.4.13]. Purified by chromatography on a DEAE-cellulose column, while eluting with O.IM NaCl, pH 7.0, followed by chromatography on Sephadex G-200. Final preparation was free from plasminogen and plasmin. [Yin and Wessler J Biol Chem 243 112 796S.]... 

Components/ mechanism of action Human plasma, fibrinogen and thrombin, virally inactivated, hemostat, sealant. Autologous fibrinogen -t-platelet-rich plasma, hemostatic gel. Bovine collagen, bovine thrombin, plus autologous human plasma, hemostatic agent. Bovine collagen and bovine thrombin. Expands 20% which aids in hemostatic effect. 

Prior, J., Wallace, D., Hamer, A. and Powers, N., A sprayable hemostat containing fibrillar collagen, bovine thrombin, and autologous plasma. Ann. Thome. Surg., 68, 479-485 (1999). 

Fibrin is an elastic filamentous protein elaborated from its precursor, fibrinogen, which is present in plasma at high concentration. Fibrin is formed in response to the actions of thrombin. Thrombin cleaves small peptides from the fibrinogen molecule, forming fibrin monomers that will begin to polymerize and become crosslinked. 

In some cases, receptor inactivation, e.g., of the V2 vasopressin receptor, is mediated by agonist-induced enzymatic cleavage of the GPCR. This nonendocytic proteolysis is promoted by a plasma membrane-associated metalloprotease. Proteinase-activated receptors (PARs) such as the thrombin receptor also follow a distinctly different pathway. PARs require the enzymatic cleavage of their N terminus, and the newly generated N terminus activates the receptor. Once... 

Ichinose A, Fujikawa K, Suyama T The activation 80 of pro-urokinase by plasma kallikrein and its inactivation by thrombin. J Biol Chem 1986 261 3486-3489. 81... 

Figure 51-2. Diagrammatic representation (not to scale) of the binding of factors Va, Xa, Ca +, and prothrombin to the plasma membrane of the activated platelet. The sites of cleavage of prothrombin by factor Xa are indicated by two arrows. The part of prothrombin destined to form thrombin is labeled prethrombin.The Ca " is bound to anionic phospholipids of the plasma membrane of the activated platelet.

Four naturally occurring thrombin inhibitors exist in normal plasma. The most important is antithrombin III (often called simply antithrombin), which contributes approximately 75% of the antithrombin activity. Antithrombin III can also inhibit the activities of factors IXa, Xa, XIa, Xlla, and Vila complexed with tissue factor. a2-Macroglobulin contributes most of the remainder of the antithrombin activity, with heparin cofactor II and aj-antitrypsin acting as minor inhibitors under physiologic conditions. 

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