Clotting factors listed

Genetic manipulation (GM) also offers the prospect of healthier animals with improved resistance to diseases such as mastitis or to the ticks that can infest cattle, thus reducing the need for antibiotics and pesticides. Medicines may be produced in the milk of cows. For example, GM cows could produce milk with a clotting factor for hemophiliacs, milk containing human serum albumin for blood transfusions, or milk with a hepatitis vaccine. Several of these medicines could be produced much more efficiently than with the technologies currently used. Some of the potential changes that can be brought about in milk are listed in Table 1. 

Figure 11-1. Blood clotting. (This represents an abbreviated scheme. Roman numerals indicate clotting factors as listed in Table 11-1).

Recombinant DNA technology provides a powerful tool for new pharmaceutical product development and production. Table 6.4 lists the rDNA-produced drugs and vaccines approved by the U.S. FDA through the year 2000. The biotech products include hormones, enzymes, cytokines, hematopoietic growth factors, other growth factors, blood clotting factors and anticoagulants, and vaccines. 

Release of thrombin fi-om its inactive zymogen. Prothrombin (see), is the penultimate step in a series of reactions, each of which releases an active serine protease from an inactive precursor in the blood. It is an example of cascade regulation, in which each activated protease activates the next precursor down the line, increasing amounts of material being involved at each step (i.e. there is amplification). The clotting factors are listed in the Table. The assigned Roman numerals are historical, and the activated form is indicated by the subscript a (e.g. XII,). 

Biocompatible materials in contact with blood must meet the conditions listed in Table 2. These conditions are partially interdependent. Thus, the requirement of antithrombogenicity rests on the condition that neither thrombocytes, clotting factors nor inhibitors may be damaged. Since failure to meet this rather complex requirement can have fatal consequences in only seconds, it is the main - and often only - requirement considered, during the development of biomaterials and one that is truly difficult to fulfill. 

The coagulation proteins that are synthesized in the liver are listed in Table 47-1. These proteins interact to produce a fibrin clot. Inhibitors of the coagulation system, including antithrombin, protein C, and protein S, are also synthesized in the fiver. Some of the coagulation factors (II, VII, IX, and X) require vitamin K for posttranslational carboxylation within the hepatocyte. Protein C and S are also carboxylated by a vitamin K-dependent enzyme. Activated protein C in plasma inhibits coagulation by inactivating factors V and... 

A list of the numerous enzymes and cofactors involved in blood clotting is given in Table 25.3. These are usually known by a factor number using roman numerals and, since both an active and an inactive form exist, the active form is given the subscript a. This terminology has already been used for the fibrin-stabilizing factor. Factor Xllla, and for thrombin. Factor Ila. Sometimes a factor has an alternative name which is usually either that of the patient in which a defect in the factor was first recognized or the worker who first described the defect. Where such names are... 

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