Antithrombin III protein

Clotting disorders (factor 5 leiden, deficiency of antithrombin III, protein C, or protein S)... 

Affinity chromatography is used in the preparation of more highly purified Factor IX concentrates (53—55) as well as in the preparation of products such as antithrombin III [9000-94-6] (56,57). Heparin [9005-49-6], a sulfated polysaccharide (58), is the ligand used most commonly in these appHcations because it possesses specific binding sites for a number of plasma proteins (59,60). 

Factor VIII, immunoglobulin, and albumin are all held as protein precipitates, the first as cryoprecipitate and the others as the Cohn fractions FI + II + III (or FII + III) and FIV + V (or FV), respectively (Table 7, Fig. 2). Similarly, Fractions FIVj + FIV can provide an intermediate product for the preparation of antithrombin III and a-1-proteinase inhibitor. This abiUty to reduce plasma to a number of compact, stable, intermediate products, together with the bacteriacidal properties of cold-ethanol, are the principal reasons these methods are stiU used industrially. 

Alpha-1-proteinase inhibitor and antithrombin III are used to treat people with hereditary deficiencies of these proteins. Both can be recovered from Cohn Fraction IV (Table 7) using ion-exchange chromatography (52) and affinity chromatography (197), respectively. Some manufacturers recover antithrombin III directiy from the plasma stream by affinity adsorption (56,198,199). 

An important namral inhibitor of coagulation is antithrombin III genetic deficiency of this protein can result in thrombosis. 

Protein C, protein S, antithrombin III, activated protein C resistance, lipoprotein(a) anticardiolipin antibodies, lupus anticoagulant, prothrombin gene mutation 20210a... 

Alphafoetoprotein, Ancrod, Anti-D Immunoglobulin, Antithrombin III total, Apolipoprotein B, Haemoglobin A2 and F Lysate, Heparin, Protamine Protein C, Fibrinogen, Plasmin a-Thrombin, Antithrombins, (3-Thromboglobulin, Haemiglo-bincyanide... 

There are various inhibitors within the coagulation system that counterregulate activation of the coagulation cascade. Among them, antithrombin III (AT-III) and protein C (PC) are the most important (SI). AT-III binds in the presence of heparin the activated factors F-IXa, F-Xa, and F-IIa (thrombin). PC is activated by a complex formed between thrombin and thrombomodulin, a surface protein of endothelial cells. Once activated, PC in the presence of protein S (PS) specifically degrades activated factors F-Va and F-VIIIa. PC decreases in the course of sepsis in relation to the severity of the condition (L15). Experimental studies have... 

Laboratory tests for hypercoagulable states should be done only when the cause of the stroke cannot be determined based on the presence of well-known risk factors. Protein C, protein S, and antithrombin III are best measured in steady state rather than in the acute stage. Antiphospholipid antibodies are of higher yield but should be reserved for patients aged less than 50 years and those who have had multiple venous or arterial thrombotic events or livedo reticularis. 

Thrombogenic mutations (e.g., factor V Leiden, protein C or S deficiency, antithrombin III... 

Based on the mixed-phase method, ACE is introduced for studying the interaction of heparin with the serine protease inhibitors, antithrombin III (ATIII) and secretory leukocyte proteinase inhibitor (SLPI) (85). An etched capillary, to which heparin has been covalently immobilized, was used in this study. This modified capillary both afforded an improvement in the separation of heparin-binding proteins and required a lower quantity of loaded protein. 

Antithrombin HI (ATHI). There are only a few references concerning the evaluation of antithrombin III (AT III) in cerebrospinal fluid. Extension of evaluated groups of patients is not sufficient a comparison with other CSF protein fractions and with CSF cytological findings was not done. Some experimental works describe the vasorelaxant effect of AT III on brain arteries, and the inhibitory influence of AT III in subarachnoid hemorrhage on onset of vasospasms is expected (W2). AT III also plays a possible role in etiopathogenesis of ischemic stroke (A19, W2). 

Determination of acute-phase proteins (CRP, orosomucoid, haptoglobin, transferrin, prealbumin), immunoglobulins (IgA, IgG, IgM), compressive markers (albumin, fibrinogen), markers of tissue destruction (Apo A-I, A-II, Apo B), components of complement (C3, C4), proteinase inhibitors (antithrombin III, a -antitrypsin). The measurement was performed simultaneously in CSF and in serum... 

B. Thrombocytopenia is a frequent side effect association with heparin. This reduction in the level of circulating platelets increases bleeding. Purple toes are encountered during warfarin therapy. Heparin may be administered to pregnant mothers without risk to the fetus. Heparin requires antithrombin III for its anticoagulant action, but does not increase the level of this protein in the blood. 

Interactions of heparinoids with the most diverse proteins such as enzymes and enzyme inhibitors, cytokines, and adhesion molecules have been described. To date, many more than a hundred heparin binding proteins are known. A number of heparin binding proteins are members of the serpin family of serine protease inhibitors. The best described example is antithrombin [4]. Antithrombin III (AT III) is able to inhibit various serine proteases involved in the blood coagulation process by formation of stable, equimolar complexes. Binding of heparin to AT III accelerates the kinetics of this complex formation by several orders of magnitude. This has been the basis for the successful clinical use of heparin as an anticoagulant for nearly sixty years. 

Ikada and coworkers also studied the blood compatibility and protein denaturation properties of heparin covalently and ionically bound onto polymer surfaces [513], Both types of bound heparin gave deactivation of the coagulation process. Clotting deactivation was attributed to a heparin/ antithrombin III complex by covalently bound heparin which gave adsorbed protein denaturation and platelet deformation as compared with lack of these features with ionically bound heparin. 

Table 11 demonstrates, as in the previous case, the increased amount of immobilized heparin when the spacer was used the anticoagulant activity of immobilized heparin being around 10% of the initial heparin activity. The reason for the observed loss of initial activity is probably the inaccessibility of the immobilized heparin for high-molecular proteins (thrombin with a molecular mass of 34000 and antithrombin III with a molecular mass of 65 000) as the permeability of the grafted gels, whose water content was only 55 %, [Pg.113]

The risk of thromboembolic complications when diethylstilbestrol is used in treating prostatic cancer is well documented, but there has been some doubt as to the mechanisms involved. Oral diethylstilbestrol diphosphate 300 mg/day has been compared with LR-RH agonist therapy or no treatment in 35 patients with prostatic cancer (5). Diethylstilbestrol reduced the concentrations of protein S to below the lower limit of normal in 24 of the 35 cases. There was also some reduction in antithrombin III concentrations. These results were consistently confirmed in a follow-up group of eight further patients who took diethylstilbestrol. Since these very low concentrations of protein S are virtually the same as those found in congenital deficiency, it seems likely that this plays a role in the development of cardiovascular complications during diethylstilbestrol treatment. 

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