From Big Medical Encyclopedia

PARAKOAGULYTsIYa (Greek para near + coagulation) — a phenomenon of education in a blood plasma under the influence of thrombin of the proteinaceous complexes consisting from incomplete or which are partially split by plasmin and connected with each other and to fibrinogen of molecules of monomers of fibrin — fibrin-monomers.

Proteinaceous complexes are not capable to be polymerized in fibers of fibrin (see), they coagulate only at addition to a blood plasma of prot-aminsulphate, ethanol or ethanol mixture and R-naphthol. Preservation of these complexes in the dissolved look is promoted by the molecules of fibrinogen which are their part (see), and also the eliminating from fibrin-monomers B of fragments catalyzed by plasmin and formation of the incomplete, deprived only peptides A fibrin-monomers (des - And - fibrin). By means of an affine chromatography (see) on agarose with the immobilized fibrinogen heterogeneity of the proteinaceous complexes capable to P. is established; one of them have a pier. the weight (weight) more than 1 • 10e, others are low-molecular, their pier. weight apprx. 4,5 - 104. These complexes are not curtailed under the influence of small and medium concentration of thrombin (see), but as for the first time showed D ershen and Stsukhet (M. Derechin, S. Szuchet, 1956), coagulate at introduction to a blood plasma of a protaminsulfat. This phenomenon received the name of a phenomenon of paracoagulation. Proteinaceous complexes coagulate also under the influence of other cationic proteins, ethanol, spirit solution of R-naphthol, freezings (cryofibrin) and nek-ry snake poisons. In a blood plasma of healthy people the quantity of proteinaceous complexes usually does not exceed 0,02 g) l, at pregnancy it reaches 0,05 — 0,10 g! l. Their concentration sharply increases (from 0,20 to 2,0 g! l and more) at intravascular activation of coagulant system of blood (see), in particular at intravenous infusion of thrombin, and also at sharp activation of a fibrinolysis (see) Streptokinasa, urokinase, etc.

Increase in quantity of proteinaceous complexes is often observed at the explicit and latent thromboses (see), a syndrome of the disseminated intravascular blood coagulation and microthrombovasculites (see the Vasculitis, Shenleyn — Genokh a disease), a glomerulonephritis (see), late toxicoses of pregnant women (see), a heart attack and ischemia of various bodies, at many patients with malignant new growths, at the diseases which are complicated by a trombogemorragichesky syndrome (see the Trombogemorragichesky syndrome, t. 29, additional materials), and also in the course of thrombolytic therapy.

Biol. value P. is, obviously, that it promotes maintenance of liquid state of blood at activation of coagulant system of blood and circulation in blood of thrombin, blockade of microvessels by the friable mass of fibrin (see) and blood clots is as a result weakened (see Thrombosis). At the same time it is proved that proteinaceous complexes much easier and quicker lyse with plasmin (fibrinolysin), than the turned polymers of fibrin. Therefore, in this case fibrin is exposed to fermental splitting, remaining in the dissolved state, not turning into clots and blood clots (this type of a fibrinolysis was mistakenly treated as fibrinogenoliz). Proteinaceous complexes and their fragments are exposed to elimination from a vascular bed by phagocytosis by cells of system of mononuclear phagocytes (see). Life expectancy of proteinaceous complexes in a blood-groove is many times shorter, than fibrinogen.

Laboratory methods of a research P. are widely used in a wedge, practice and in pilot studies for identification of an intravascular blood coagulation and a trombinemiya that matters in diagnosis of trombofilichesky states (for to-rykh the multiple thrombogenesis), thromboses, a syndrome of the disseminated intravascular blood coagulation, mikrotrombova-skulit, and also of control of antitrombotichesky therapy (see Thrombosis is characteristic). These methods subdivide into two groups. Carry a method of definition of soluble cryofibrin to the first group, about-taminsulfatny, ethanol and r-naftolovy methods, and also a method of secondary coagulation of blood serum at addition of poison of a snake to it (e.g., a sandy efa). These kachestven' ny or approximate (total) quantitative methods are not difficult and are carried out with the minimum expense of time. With their help define total quantity of protein in the allocated proteinaceous complexes.

Soluble cryofibrin (cryofibrinogen) is determined by sedimentation of proteinaceous precipitated calcium superphosphate in the plasma stabilized by citrate in mix with aminocaproic to - that or heparin. At the same time plasma during 18 — 24 hours is cooled at t ° 4 °. Control experiment is put with blood serum and defibrinated by warming up (4 min. at t ° 56 °) plasma for an exception of a cryoglobulinemia and other TYPES of COLD precipitation (see. Hemolitic anemia, Reynaud disease). The method is used in pilot studies.

The Protaminsulfatny method is based on coagulation of soluble fibrin by sulfate of the protamin (see Protamin sulfate) used most often in final concentrations (0,2 — 0,3%). Not all samples of a protaminsulfat are equally suitable for this method therefore their preliminary testing and selection of optimum concentration of drug are necessary. There is a number of modifications of a protaminsulfat-ny method, including the polukolichestven-ny methods (e.g., a dilution method of a protaminsulfat) based on definition of that smallest concentration of a protaminsulfat, at a cut the coagulate is still formed of proteinaceous complexes, or the methods based on sedimentation of proteinaceous complexes by obviously excess quantity of a reactant (0,8%) with the subsequent definition of protein in gel. Apply also graduated protaminsulfatny method, at Krom part the studied blood plasma in 5, 10, 20 and 40 times then add 1% to these samples solution of a protaminsulfat. Establish the greatest cultivation, at Krom the coagulate is formed. In case of a positive take in a blood plasma in 30 min. or later the jellylike clot is formed, and at a large number of proteinaceous complexes and dominance of their krupnomolekulyarny forms the clot arises earlier, and it is more dense.

The ethanol method is based on sedimentation of products of P. in the form of a jellylike clot at addition of 0,15 ml of 50% of solution of ethanol to 0,4 ml of the studied blood plasma cooled to 4 — 8 °. The blood plasma rich with thrombocytes is stabilized by 3,8% solution of sodium citrate in mix from 0,1 M solution aminocaproic to - you. Results of a method are considered positive at gelation the first 10 min.

At statement of the ^-naftolovy test for sedimentation fibrin-monomer-nykh of complexes 5 drops [3 naphthols add the ethanol dissolved in 50% solution to 1 ml of a blood plasma.

The method of secondary coagulation under the influence of poison of a snake (a sandy efa) is that to 0,5 ml of the blood serum received after coagulation of a blood plasma by thrombin (activity of 1 PIECE) add 0,1 ml of solution of poison to concentration 1:5-10“ 3 — 1:1(G4. In the presence of proteinaceous complexes the second jellylike clot is formed, in Krom the amount of protein is established to one of methods of quantitative definition of fibrinogen (see).

The affine chromatography (see) and gel-filjt, the radio set concerns to the second group of methods (see), to-rye are difficult highly specific methods of quantitative definition of proteinaceous complexes and preparative division of various subfractions of proteins.

G1 methods. in a complex with others are used in a wedge, practice for identification of an intravascular blood coagulation. So, efficiency of treatment by heparin (see) is reflected in transition of positive takes of methods, with the help to-rykh proteinaceous complexes come to light, in negative in this connection use in dynamics ethanol and about-taminsulfatnogo methods is important for assessment of efficiency of therapy, the correct selection of doses of heparin. Different methods of identification of proteinaceous complexes are not equivalent and do not replace each other therefore valid diagnostic conclusions can be drawn only by results of several methods executed at the same time. So, the ethanol method can yield a positive take, and pro-that-minsulfatny — negative and vice versa. Both methods often yield negative takes in late stages of an acute syndrome of the disseminated intravascular blood coagulation (in the period of deep hypocoagulation) that is connected with insufficient stabilization of products of P. owing to the expressed pshofibri-nogenemiya (lower than 0,5 g 1 l), and partly with intensive splitting fibrin-monomers plasmin. The method of secondary coagulation under the influence of poison of a snake reveals fibrin-monomer-nye complexes while ethanol and protaminsulfatny methods do not reveal them, including and in late stages of an acute syndrome of the disseminated intravascular blood coagulation. In the terminal period of this syndrome poison also loses ability to cause coagulation that is a bad predictive sign.

It should be noted that false positive results of methods P. are observed at a considerable fibrinosis, a paraprotein - emiya — a multiple myeloma (see), Valdenstrem's diseases (see Valden-strem a disease), diseases of heavy chains (see. Heavy chains of a disease), etc.

Similar with P, disturbances in system of a hemostasis form at use of drugs of defibrinating action — an arvina, an ankroda, defibraza, etc. These fermental drugs extracted from poison of nek-ry snakes (see. Snake poison), unlike thrombin only peptides A, forming incomplete chip off from molecules of fibrinogen fibrin-monomers (des - And - fibrin). Complex connections fibrin-monomers with fibrinogen and early products of a fibrinolysis (see) lead to more or less deep defibrinating of plasma and accumulation in it of proteinaceous complexes owing to what results of methods, with the help to-rykh them reveal, sharply positive.

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3. S. Barkagan.