Clotting of blood

Another physiologically important quinone is vitamin K Here K stands for koag ulation (Danish) because this substance was first identified as essential for the normal clotting of blood... 

Heparin inhibits the formation of fibrin clots, inhibits the conversion of fibrinogen to fibrin, and inactivates several of the factors necessary for the clotting of blood. Heparin cannot be taken orally because it is inactivated by gastric acid in the stomach therefore, it must be given by injection. Heparin has no effect on clots that have already formed and aids only in preventing the formation of new blood clots (thrombi). The LMWHs act to inhibit clotting reactions by binding to antithrombin HI, which inhibits the synthesis of factor Xa and the formation of thrombin. 

Clotting of blood is, of course, one of the more significant ways in which the body protects itself from excessive blood loss after injury. 

Eicosanoids are involved in control of a number of physiological processes that are essential to life. Some information on each role is provided below but further detail can be found in other chapters clotting of blood (Chapters 17 and 22) menstruation and parturition (Chapter 19) secretion of protons in the stomach (Chapter 4) pain and fever (Chapter 18). 

In the early 1980s, the development of HIV/AIDS in young blood transfusion patients was a powerful incentive to find other sources for the blood-derived proteins used to treat hemophilia, a group of inherited disorders affecting the clotting of blood. Hemophilia has... 

Therapy with heparin occurs in an inpatient setting. Heparin inhibits both in vitro and in vivo clotting of blood. Whole blood clotting time and activated partial thromboplastin time (aPTT) are prolonged in proportion to blood heparin concentrations. 

Mechanism of Action A fat-soluble vitamin that promotes hepatic formation of coagulation factors II, VII, IX, and X. Therapeutic Effect Essential for normal clotting of blood. 

The induction of a change in one protein by interaction with another protein is a phenomenon that is met also in the construction of microtubules, ribosomes, cilia, and myofibrillar assemblies of muscle. It is basic to the assembly of the many labile but equally real cascade systems of protein-protein interactions such as that involved in the clotting of blood (Chapter 12) and signaling at membrane surfaces. 

Elaborate cascades initiate the clotting of blood (Chapter 12) and the action of the protective complement system (Chapter 31). Cascades considered later in the book are involved in controlling transcription (Fig. 11-13) and in the regulation of mammalian pyruvate dehydrogenase (Eq. 17-9), 3-hydroxy-3-methyl-glutaryl-CoA reductase and eicosanoids (Chapter 21), and glutamine synthetase (Chapter 24). 

The clotting of blood following injury and the subsequent dissolving of the clot are familiar phenomena... 

In biological science, the term coagulation has two somewhat more specific meanings (l)The clotting of blood or lymph. (2) The changes produced in tissue of the application of increased temperatures or by cenain chemicals. See also Anticoagulants and Blood. 

SYNERESIS. The contraction of a gel with accompanying pressing out of the interstitial solution or serum. Observed in the clotting of blood, with silicic arid gels. etc. See also Colloid Systems. 

Tphe kinetics of the protease-triggered clotting of blood and milk has been formulated in a number of recent publications from this laboratory (1,2,3). In milk clotting, the coagulation is initiated through the limited proteolysis of -casein, the milk protein component which normally protects the casein micelles from flocculation by calcium ions (4). Kappa-casein is a single polypeptide chain of 169 residues, the sequence... 

Clotting of blood, which protects against hemorrhage, involves the sequential initiation, interaction, and completion of several stages in hemostasis (Table 4.2). 

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