Blood Prothrombin

Effect on blood Platelets are the important factors in thrombus formation and aspirin has been shown to inhibit platelet aggregation. They reduce the blood prothrombin level by inhibition of prothrombin synthesis and prothrombin time is prolonged. The aspirin suppresses the synthesis of thromboxane (TXA ) in the platelets. They also prolong the bleeding time due to prevention of platelet aggregation which may be due to inhibition of release of adenosine diphosphate (ADP) from the platelets by salicylates. 

Compounds with vitamin K activity (Table 6.2) are required in our diets for y-carboxyglutamate biosynthesis (Table 4.1). This amino acid is produced from certain protein glutamyl residues by carboxylation. Proteins that contain y-carboxyglutamate are blood prothrombin and coagulation factors VII, IX, and X (see Chapter 7). Other proteins of this type are osteocalcin from bone and several kidney and muscle calcium-binding proteins. 

High levels of this material in the diet caused degenerative changes in the liver, kidney, adrenal medulla and thyroid of rats and a decrease blood prothrombin content in rats and dogs. Mutagenicity This material was not mutagenic in an Ames bacterial assay. Acute oral toxicity (LD50) 7580 mg/kg [Rat],... 

Blood albumin - decreased Blood bilirubin - increased Blood IgG-specific antibodies - present Blood IgM-specific antibodies - present Blood liver enzymes - increased Blood prothrombin time - increased... 

Blood platelets, total - decreased (thrombocytopenia) Blood prothrombin time - increased Blood WBC - decreased (leukopenia)... 

Blood partial thromboplastin time (PTT) - increased Blood prothrombin time (PT) - increased Blood-specific detection - present... 

Exposure Routes, Symptoms, Target Organs (see Table 5) ER Inh, Ing SY Epis, excess bleeding from minor cuts, bruises smoky urine, black tarry stools abdom, back pain TO Blood prothrombin First Aid (see Table 6) Eye Irr Immed Breath Resp support Swallow Medical attention Immed ... 

Yang C-L, et al. Design and evaluation of a portable optical-based biosensor for testing whole blood prothrombin time. Talanta 2013 116 704-11. 

Coagulation Time, Blood Prothrombin, and Throhboplastic Activity in Pregnant Subjects Compared with Normal Controls ... 

Blood prothrombin 109% (7th month) 118% (at term) Decreased Nearly always below 70%... 

Factor V. High in sialic acid content. Factor V is a large asymmetric single-chain glycoprotein that becomes an active participant in the coagulation cascade when it is converted to its active form by a-thrombin. Approximately 25% of human Factor V is found in the whole blood associated with platelets. Factor V is an essential cofactor along with Factor Xa plus phosphohpid plus Ca " in the conversion of prothrombin to thrombin. 

Calcium is essential to several steps in the enzyme cascade of the blood clotting process, such as the conversion of prothrombin to thrombin (23). Clotting can be inhibited in stored blood suppHes by addition of complexing agents such as EDTA or citrate which reduce the levels of the free ion, Ca(Il). 

Prothrombin (Factor II, from equine blood plasma) [9001-26-7] 72,000. Purified by two... 

Administration of zafirlukast and aspirin increases plasma levels of zafirlukast, When zafirlukast is administered with warfarin, there is an increased effect of the anti coagulant. Administration of zafirlukast and theophylline or erythromycin may result in a decreased level of zafirlukast. Administration of montelukast with other drugs has not revealed any adverse responses. Administration of montelukast with aspirin and NSAIDs is avoided in patients with known aspirin sensitivity. Administration of zileuton with propranolol increases the activity or the propranolol with theophylline increases serum theophylline levels and with warfarin may increase prothrombin time (PT). A prothrombin blood test should be done regularly in the event dosages of warfarin need to be decreased. 

Before administering the first dose of warfarin, die nurse questions the patient about all drags taken during the previous 2 to 3 weeks (if the patient was recendy admitted to the hospital). If the patient took any drug before admission, the nurse notifies the primary healdi care provider before the first dose is administered. Usually, the prothrombin time (PT) is ordered and die international normalized ratio (INR) determined before tiierapy is started. The first dose of warfarin is not given until blood for a baseline PT/ INR is drawn. The dosage is individualized based on die results of the PT or die INR. 

D. checks to see that blood has been drawn for a baseline prothrombin time... 

In the case of prothrombin and related clotting factors, interruption of the vitamin K cycle leads to the production of nonfunctional, undercarboxylated proteins, which are duly exported from hepatocytes into blood (Thijssen 1995). They are nonfunctional because there is a requirement for the additional carboxyl residues in the clotting process. Ionized carboxyl groups can establish links with negatively charged sites on neighboring phospholipid molecules of cell surfaces via calcium bridges. 

Table 32-3 summarizes laboratory results obtained on patients with three different causes of jaundice—hemolytic anemia (a prehepatic cause), hepatitis (a hepatic cause), and obstruction of the common bile duct (a posthepatic cause). Laboratory tests on blood (evaluation of the possibihty of a hemolytic anemia and measurement of prothrombin time) and on semm (eg, electrophoresis of proteins activities of the enzymes ALT, AST, and alkahne phosphatase) are also important in helping to distinguish between prehepatic, hepatic, and posthepatic causes of jaundice. 

Prothrombin and several other proteins of the blood clotting system (Factors VII, IX and X, and proteins C and S) each contain between four and six y-carboxygluta-mate residues which chelate calcium ions and so permit the binding of the blood clotting proteins to membranes. In vitamin K deficiency or in the presence of warfarin, an abnormal precursor of prothrombin (preprothrombin) containing little or no y-carboxyglutamate, and incapable of chelating calcium, is released into the circulation. 

The Final Common Pathway of Blood Clotting Involves Activation of Prothrombin to Thrombin... 

Wu, H. and Bruley, D.F, Homologous Human Blood Protein Separation Using Immobilized Metal Affinity Chromatography Protein C Separation from Prothrombin with Application to the Separation of Factor IX and Prothrombin, Biotechnol. Prog., 15, 928, 1999. 

Check complete blood count, prothrombin time, international normalization ratio, activated partial thromboplastin time, fibrinogen levels... 

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