Thrombocyte factor

Circulating blood contains practically no thrombin, only its precursor prothrombin. The conversion of prothrombin to thrombin is usually considered to be the first phase of blood clotting. Numerous factors are involved in this preliminary phase First, thrombokinase from tissue with the accelerators and Ca++ second, thrombokinase from blood, which is formed by the thrombocyte factor in presence of at least four plasma factors and Ca++. The conversion prothrombin — thrombin proceeds autocatalytically the process is accelerated by the action of newly formed thrombin on factor V proaccelerin) by converting this factor into the active factor... 

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). 

The fats also have a plastic function as they are included in cell membranes and other cell structures. The central and peripheral nervous systems are rich in lipids. PNFA are included in cell membranes, with their most significant function being the synthesis of cell hormones — prostaglandins. The properties of cell membranes as well as their interaction with external factors depend on the relation of PNFA concentration in cell components. In humans, prostaglandins are created not only in tissues but also in thrombocytes (thromboxanes) and in leucocytes (leukotrienes). The biological action of thrombocytes is extremely variant and depends on PNFA type which are the basis for fatty acid creation. 

Both pathways depend on the presence of activated thrombocytes, on the surface of which several reactions take place. For example, the prothrombinase complex (left) forms when factors Xa and 11, with the help of Va, bind via Ca "" ions to anionic phospholipids in the thrombocyte membrane. For this to happen, factors 11 and X have to contain the non-proteinogenic amino acid y-carboxygluta-mate (Gla see p. 62), which is formed in the liver by post-translational carboxylation of the factors. The Gla residues are found in groups in special domains that create contacts to the Ca "" ions. Factors Vll and IX are also linked to membrane phospholipids via Gla residues. 

In the course of the above-mentioned mechanisms Silics remains unchanged and thus preserves its activity during its residence in the intestine. Silics may also have promise in the clinical treatment for some internal diseases. The major lines of research into applications of this medicinal preparation in the relevant therapies are presented in Table 7. Of significance is the ability of Silics to lower cholesterol levels and triglycerides, as well as to retard aggregation of thrombocytes. Thus, with the help of Silics it becomes possible to treat the main pathogenic factors of atherosclerosis, namely hyperlipidemia and hypercoagulation (Table 7). 

The determination of ammonia in blood is carried out enzymatically, which is considered to be specific, precise and simple. (48) Serious mistakes can easily occur during the preanalytical phase of ammonia determination, making it imperative to comply with the standardized method of taking a blood sample, (s. p. 91) EDTA blood should be taken with the addition of sodium borate and L-serine. Furthermore, elevated serum y-GT activity and increased thrombocytes cause the ammonia level to rise, as does cigarette smoking prior to blood collection. Even minor haemolysis (e. g. in the event of prolonged transport) will spoil the blood for ammonia determination, since the ammonia concentration of erythrocytes is three times that found in plasma. Besides these interfering factors, ammonia concentration is influenced by (7.) the metabolic performance of the urea cycle, (2.) the extrahepatic formation and elimination of ammonia, and (5.) the acid-base status. 

Thrombocyte dysfunction frequently emerges in the course of liver diseases and their complications, especially in the case of coagulation disorders and elevated fibrinolysis. Thus a decrease in both thrombocyte aggregation and the release of platelet factor 3 may occasionally be witnessed in cirrhosis. In most cases, this is... 

Fries and Hirschfeld (1977) observed purpura based on allergic vasculitis with arthritis at normal thrombocyte values and intact coagulation factors after cotrimoxazole in a 71-year-old man. 

Cisplatin is used for the treatment of ovarian and cervical carcinomas small cell and non-small cell bronchial and lung carcinomas testicular, endometrial, bladder, and prostate carcinomas tumors of the head and throat as well as sarcomas and melanomas. The treatment with cisplatin is complicated by the presence of considerable side effects, whereby the high nephrotoxicity is an especially dosage-limiting factor. Other side effects include hair loss, a reduction of leukocytes and thrombocytes (anemia), an impairment of the taste and hearing senses, as well as nausea and vomiting. 

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. 

Besides histamine, 5-hydroxytryptamine has been thought more recently to be a factor of importance in allergic and inflammatory diseases. In antigen-antibody reactions, amounts of 5-hydroxytryptamine, besides those of histamine, are liberated from the thrombocytes. The subcutaneous injection of very small amounts of 5-hydroxytryptamine causes a local oedema damaging the capillaries. In rats 5-hydroxytrypt-... 

Kiesewetter H, Jung F, Pindur G, Jung EM, Mrowietz C, Wenzel E (1991) Effect of garlic on thrombocyte aggregation, microcirculation, and other risk factors. Int J Clin Pharmacol Ther Toxicol 29(4) 151-155... 

Koch E (2005) Inhibition of platelet activating factor (PAF)-induced aggregation of human thrombocytes by ginkgolides considerations on possible bleeding complications after oral intake of Ginkgo biloba extracts. Phytomedicine 12(1-2) 10-16... 

After the stimulation of cells with embryonic bovine serum or thrombocytic growth factor, the labelled HA (after addition into the cultural medium) was detected in the phials and cell cytoplasm. Distribution of HA in the cytoplasm occurs compatibly with the rough... 

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