Coagulation of plasma

The activated partial thromboplastin time (APTT), also known as the kaolin-cephalin clotting time (KCCT), primarily evaluates the intrinsic system. In-vitro coagulation of plasma is initiated by the addition of negatively charged particles such as kaolin with phospholipid, and calcium and exogenous thromboplastin. 

Furth suggests the following scheme for the coagulation of plasma ... 

Table 1. Physical and Chemical Properties of Plasma Coagulation Factors...

Medical Uses. Citric acid and citrate salts are used to buffer a wide range of pharmaceuticals at their optimum pH for stabiUty and effectiveness (65—74). Effervescent formulations use citric acid and bicarbonate to provide rapid dissolution of active ingredients and improve palatabiUty. Citrates are used to chelate trace metal ions, preventing degradation of ingredients. Citrates are used to prevent the coagulation of both human and animal blood in plasma and blood fractionation. Calcium and ferric ammonium citrates are used in mineral supplements. 

The Role of Plasma Cascade Systems in Sepsis 4.1.1. The Coagulation System... 

Nelson S., Pritt A., Marlar R. A. Rapid preparation of plasma for stat coagulation testing. Arch Pathol Lab Med 1994 118,175-6. 

For pH sensors used in in-vivo applications, especially those in continuous pH monitor or implantable applications, hemocompatibility is a key area of importance [150], The interaction of plasma proteins with sensor surface will affect sensor functions. Thrombus formation on the device surface due to accelerated coagulation, promoted by protein adsorption, provided platelet adhesion and activation. In addition, variation in the blood flow rate due to vasoconstriction (constriction of a blood vessel) and sensor attachment to vessel walls, known as wall effect , can cause significant errors during blood pH monitoring [50, 126],... 

Vitamin K activity is associated with several quinones, including phylloquinone (vitamin Kj), menadione (vitamin K3), and a variety of menaquinones (vitamin K2). These quinones promote the synthesis of proteins that are involved in the coagulation of blood. These proteins include prothrombin, factor VII (proconvertin), factor IX (plasma thromboplastin), and factor X (Stuart factor). A detailed discussion of blood coagulation is found in Chapter 22. The vitamin K quinones are obtained from three major sources. Vitamin K is present in vari-... 

Freeze-dried concentrates of plasma containing prothrombin, factors IX and X, and varied amounts of factor VII (Proplex, etc) are commercially available for treating deficiencies of these factors (Table 34-3). Each unit of factor IX per kilogram of body weight raises its activity in plasma 1.5%. Heparin is often added to inhibit coagulation factors activated by the manufacturing process. However, addition of heparin does not eliminate all thromboembolic events. 

In clinical work many biological fluids have been submitted to paper electrophoretic separation. Serum and urine have been studied extensively and the results were reviewed in Volume I of this series (p. 238). Other fluids include cerebrospinal fluid (B12, B14, E6, K18), pleura] fluid (D4), gastric juice (H6), ascitic fluid (H9), synovial fluid (W3), proteins of the lens (F4, W9, W10), aqueous humor of the eye (W12, W24), edema liquid (W23), and pericardiac effusion (G2). Apart from the general separation of plasma proteins, work has been done on special protein groups, such as lipo- and glycoproteins, muco-proteins, hemoglobins (H19), coagulation factors (05), and on other components, such as amino acids. 

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