Fibrinogens

Nanofibers of human and bovine fibrinogen with an average diameter of 

80 nm were electrospun from HFP and minimal essential medium or Earle s salt solution mixed in the ratio of (9 1), at protein concentrations of 0.083, 0.125, and 0.167 g/mL. Fine fibers with = 80 20 nm, 310 + 70 nm, and 700 + 110 nm were electrospun at the different concentrations (Wnek et al. 2003). Fibrin fibers that occur in clots typically show diameters in this same size range (d 80-90 nm). 

The interaction of actin and myosin is key to the generation of contractile forces in skeletal muscles. Skeletal muscles are composed of thick and thin filaments the thick filaments are composed primarily of myosin and thin filaments contain actin. The interaction between the two is a reversible self-assembly process that is followed by disassembly that separates actin from myosin. This separation initiates movement of myosin with respect to actin and results in shortening of the muscle, causing force generation. It is the assembly and disassembly process that we are interested in in this section. 

Researchers at SmithKline Beecham Pharmaceuticalsinvestigated the structure of the cyclic RGD-containing compound 59 (SK F 107260), a 

In a similar effort, McDowell et at Genentech used ensemble 

Hartman et al.i s at Merck Research Laboratories have also reported low molecular weight peptide mimetics of the RGD sequence. The lead compound this series (62, IC50 = 27 pM) was uncovered by directed screening of the 

Merck sample collection for compounds that possess amino and carboxylate 

Hershkoviz et the Weizmann Institute of Science achieved confor- 

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Globulins. Proteins insoluble in water, soluble in dilute salt solutions. They include such proteins as myosin from muscle, fibrinogen from blood and edcstin from hemp. 

A method for the fractionation of plasma, allowing albumin, y-globulin, and fibrinogen to become available for clinical use, was developed during World War II (see also Fractionation, blood-plasma fractionation). A stainless steel blood cell separation bowl, developed in the early 1950s, was the earhest blood cell separator. A disposable polycarbonate version of the separation device, now known as the Haemonetics Latham bowl for its inventor, was first used to collect platelets from a blood donor in 1971. Another cell separation rotor was developed to faciUtate white cell collections. This donut-shaped rotor has evolved to the advanced separation chamber of the COBE Spectra apheresis machine. 

Primary blood components iaclude plasma, red blood cells (erythrocytes), white blood cells (leukocytes), platelets (thrombocytes), and stem cells. Plasma consists of water dissolved proteias, ie, fibrinogen, albumins, and globulins coagulation factors and nutrients. The principal plasma-derived blood products are siagle-donor plasma (SDP), produced by sedimentation from whole blood donations fresh frozen plasma (FFP), collected both by apheresis and from whole blood collections cryoprecipitate, produced by cryoprecipitation of FFP albumin, collected through apheresis and coagulation factors, produced by fractionation from FFP and by apheresis (see Fractionation, blood-plasma fractionation). 

Thrombin, the two-chain derivative of the prothrombin molecule, has a molecular weight of approximately 37,000 daltons. Its proteolytic properties induce the conversion of fibrinogen to fibrin to produce the initial visible manifestation of coagulation, the soluble fibrin clot. In addition, thrombin influences the activity of Factors V, VIII, and XIII and plasmin. Thrombin affects platelet function by inducing viscous metamorphosis and the release reaction with subsequent aggregation. 

Factor II. Prothrombin is a vitamin K-dependent compound synthesized by the Hver. When prothrombin is activated it is cleaved at two sites, resulting in a two-chain molecule linked by a disulfide bond that has a molecular weight of 37,000 daltons. Thrombin is the serine protease that initiates the conversion of soluble fibrinogen into fibrin. 

Cryoprecipitate Fresh-frozen plasma Autoplex-T VIIFC VIIFvWFAg Fibrinogen Plasminogen Factor XIII all coagulation factors, r VIIFC 11 a, Vila, IXa, Xa DH American Red Cross American Red Cross Hyland, Immuno... 

Cryoprecipitate von VIIFvWFAg VIIFC, Fibrinogen Plasminogen Factor XIII Willebrand Factor products American Red Cross... 

Arvin [9046-56-4] is a purified fraction from the cmde venom of Agkistrodon rhodostoma (48). The action of this venom fraction is selectively specific for fibrinogen and can rapidly deplete fibrinogen in vivo safely from the ckculating blood. Blood without fibrinogen cannot undergo clot formation. 

The actions of plasmin on both fibrin and fibrinogen have been studied extensively. Plasmin cleaves fibrin and fibrinogen into a family of fragments known as fibrinogen and fibrin (FDP-fdp) degradation products. 

Prourokinase is a single-chain protein containing 411 amino acids (261,265,274,275). In clinical uses scu-PA does not bind to fibrin only and its use causes a decreased plasma fibrinogen of 80%. Its half-life in the circulation is 5 min. It is cleared by the fiver. It is used at 40—70 mg over 1 h and heparin is needed simultaneously. Fibrin specificity and thrombolytic efficacy are similar to that of t-PA. 

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