Blood clot times

Haematological characteristics (haemoglobin level, red blood and white blood cell counts, platelet count, blood clotting time). 

More recently chitosan polymers which are derivatives of chitin materials have evoked interest due to their bioactivity and biodegradability. For example, N-carboxybutyl chitosan has been show to effectively promote wound healing (9). Acetate, and butyrate derivatives of chitosan have decreased blood clotting time significantly (10). 

The last of the fat-soluble vitamins to be identified was vitamin K, found by Dam to be an anti-hemorrhagic factor for young chicks, distinct from vitamin C. Its structure was determined by Dam in collaboration with Karrer. Interest in the vitamin was intensified when it was discovered (Link, 1941) that dicoumarol, present in spoiled sweet clover, was the agent producing hypothrombinemia (giving prolonged blood-clotting time) in cattle. Since vitamin K is structurally similar to dicoumarol, the vitamin was presumptively implicated in thrombin formation. This has been fully substantiated by recent work on the role of vitamin K in the synthesis of prothrombin in the liver. 

Therapy with heparin occurs in an inpatient setting. Heparin inhibits both in vitro and in vivo clotting of blood. Whole blood clotting time and activated partial thromboplastin time (aPTT) are prolonged in proportion to blood heparin concentrations. 

In the absence of the vitamin, the blood-clotting time increases, since the post-translational carboxylation of several glutamate residues in prothrombin and other factors involved in blood clotting is impaired. In humans, this disorder is unknown except in cases of faulty vitamin K absorption, since the normal diet covers the need generously. 

Decreased prothrombin content of blood and blood clotting time is prolonged. 

Biota chinensis Hort. B. orientalis L. (Syn. Platycladus orientalis, Thuja orientalis) Ce Bai Ye (twig) Quercitrin, pinipicrin, thujone, essential oils.33 Hemostatic, shorten blood clotting time, antitussive. 

Rubia chinensis Regel Maack R. cordifolia Thunb. R. cordifolia L. f. pratensis (Maxim.) Kitag. R. mungista Roxb. R. sylvatica (Maxim.) Nakai Qian Cao (Madder) (root) Rubierythrinic acid, alizarin, purpurin, pseudopurpurin, munjistin.3349 Hemostatic, shorten the blood clotting time, antibacterial, antitussive, stimulate uterine contractions. 

There are several other methods for ionic attachment of heparin to polymeric materials worth mentioning. Dimethylaminoethylcellulose was treated with heparin 79). The products made from a blend of this polymer with organosilicone polymers were still in good condition after a period of more than a year. The in vitro blood clotting time was over 24 hours. 

The thromboresistant properties of polystyrene with ionically immobilized heparin is unambiguously inferior compared to the covalently bound one. For instance, the blood clotting time for some of the covalently immobilized heparincontaining samples was up to 720 min, while for polystyrene, poly-p-aminostyrene, and polytrimethyl aminostyrene with electrostatically bound heparin the blood clotting time did not exceed 35 min. 

In general, the effect of immobilized heparin on the blood contacting a polymeric surface consists in an increase of the blood clotting time even when no heparin is eluted at all (Table 12) 104-108>. 

Heparinization, as is seen from Table 12, results not only in the increase in blood clotting time, but also in an increase of the platelet adhesion the increase in both cases being more intensive the higher the content of the immobilized heparin. It should be noted that there is a complete agreement between the scientists concerning the effect of heparin on the blood clotting time the result of the contact of blood with HCP is considered analogous to that of the direct injection of soluble heparin into the bloodstream, whereas the data on platelet adhesion is quite contradictory. 

RBCT (relative blood clotting time) the time of blood clot formation on a polymer surface/the time of blood clot formation on a glass surface ... 

However, in spite of the significant diversity in the quantitative evaluation of platelet adhesion, the platelets adhered onto heparinized surfaces are neither aggregated nor activated 4-78>. In other words, the intracellular contents of the adhered platelets, which may otherwise contribute to the blood clotting process, is not evolved into the bloodstream. This conclusion is verified by the results of Table 12, which indicate that the increased platelet adhesion does not result in a worse thrombo-resistance the blood clotting time at a HCP surface is an order of magnitude higher than that at the surface of the initial non-heparinized polymer. 

More extensive studies were carried out on polymeric materials modified with a hydrogel containing covalently immobilized heparin and trypsin 136,137>. Table 18 compiles the results of in vitro tests of the thus-modified low-density polyethylene. Obviously, co-immobilization of heparin and proteolytic enzyme onto polyethylene results in an increase of the blood clotting time and decreases the number on adhered platelets as compared to immobilization of heparin alone. 

Table 22. Whole blood clotting time of PVC with heparin- and/or PGI2-immobilized hydrogels3...

Run No. Hydrogels Heparin (us) Prosta- glandin (ug) Whole blood clotting time (min) ... 

Acetaminophen [a seat a MIN oh fen] and phenacetin [fe NASS e tin] act by inhibiting prostaglandin synthesis in the CNS. This explains their antipyretic and analgesic properties. They have less effect on cyclooxygenase in peripheral tissues, which accounts for their weak anti-inflammatory activity. Acetaminophen and phenacetin do not affect platelet function or increase blood clotting time, and they lack many of the side-effects of aspirin. [Note Phenacetin can no longer be prescribed in the United States because of its potential for renal toxicity. However, it is present in some proprietary preparations.]... 

Sulfated CDs are of anionic nature and are interesting from chemical and biological points of view because of their angiogenic and antiviral properties [22,23], Sulfated derivatives are also reported to have a heparin-like activity, resulting in increase in blood-clotting times, which limits their injectable dose [7],... 

Plasticised PVC was surface modified by nucleophilic substitution of the chlorine atoms of PVC by sulphide ions in aqueous media in the presence of a phase-transfer catalyst. The modified PVC was sterilised by steam autoclaving and gamma irradiation and subjected to plasticiser extraction. Surfaces were evaluated by contact angle measurements, SEM, cell culture studies, haemolysis assay and whole-blood clotting time measurements. Mechanical properties were examined. 31 refs. 

Cystic fibrosis patients are usually advised to take more than the recommended daily amounts of these vitamins in order to prevent deficiency. A common problem associated with poor absorption of fat-soluble vitamins is deficiency of vitamin K. Vitamin K is required by the liver to produce many blood coagulation factors. Part of the problem for cystic fibrosis patients is their chronic antibiotic therapy, which decreases the bacterial population of the colon colonic bacteria synthesize vitamin K. Vitamin K deficiency leads to prolonged blood-clotting time. Vitamin D deficiency could cause rickets in a child or osteomalacia in adults. Vitamin A deficiency leads to night blindness, skin and other ocular defects. 

Superwarfarins lower the blood concentrations of the vitamin K-dependent clotting factors II, VII, IX and X this results in prolongation of prothrombin time (PT) and partial thromboplastin time (PTT). PT and PTT should be repeated at least twice daily until a normal PT and PTT are established. Also, the blood clotting time and the bleeding time should be measured. Blood is often demonstrable in the excreta. Secondary hypochromic or microcytic anemia may be marked (Goldfrank et al, 2002 Nelson et al, 2006). 

Loss of hair Liver is enlarged and becomes cirrhotic Decrease in blood clotting time. 

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