Biomaterial Database

In vitro effect on Heptest of low molecular weight heparin fractions and preparations with various anti-IIa and anti-Xa activities. 1990

L Bara, and J Mardiguian, and M Samama

Laboratoire Central d'Hematologie, Hotel-Dieu, Paris, France.

The Heptest heparin assay has recently been introduced, and evaluated for the laboratory monitoring of patients receiving low molecular weight heparins (LMWH). The aim of the present study was to elucidate the relative role on the Heptest assay of the anti-factors Xa and IIa activities present in the three types of compounds that possess: 1. exclusively anti-Xa activity (LF1: LMWH fractions with MW ranging from 1,200 to 4,200 D.); 2. both anti-Xa and anti-IIa activities (LF2 with MW from 4,800 to 12,000 D.); 3. exclusive anti-IIa activity (Hirudin and Dermatan Sulfate). All compounds studied demonstrated dose-dependent activities in both amidolytic and clotting assays. The LF2 in contrast to the LF1, additionally enhanced the clotting times of Heptest. This enhancement was shown to be due to the anti-Factor IIa activity of the agents. Heptest does not exclusively reflect Anti-Xa activity since it is influenced by agents containing exclusive anti-IIa activity like Hirudin and Dermatan Sulfate. At low concentrations of LF2, Heptest measures predominantly the anti-factor Xa activity while at higher concentrations it is influenced by the combined activity of anti-factor Xa and anti-factor IIa. However, Heptest sensitivity to anti-factor IIa is significantly lower than for anti-Xa activity.

UI	MeSH Term	Description	Entries
D008991	Monitoring, Physiologic	The continuous measurement of physiological processes, blood pressure, heart rate, renal output, reflexes, respiration, etc., in a patient or experimental animal; includes pharmacologic monitoring, the measurement of administered drugs or their metabolites in the blood, tissues, or urine.	Patient Monitoring,Monitoring, Physiological,Physiologic Monitoring,Monitoring, Patient,Physiological Monitoring
D011516	Prothrombin	A plasma protein that is the inactive precursor of thrombin. It is converted to thrombin by a prothrombin activator complex consisting of factor Xa, factor V, phospholipid, and calcium ions. Deficiency of prothrombin leads to hypoprothrombinemia.	Coagulation Factor II,Factor II,Blood Coagulation Factor II,Differentiation Reversal Factor,Factor II, Coagulation,Factor, Differentiation Reversal,II, Coagulation Factor
D002807	Chondroitin	A mucopolysaccharide constituent of chondrin. (Grant & Hackh's Chemical Dictionary, 5th ed)
D003871	Dermatan Sulfate	A naturally occurring glycosaminoglycan found mostly in the skin and in connective tissue. It differs from CHONDROITIN SULFATE A (see CHONDROITIN SULFATES) by containing IDURONIC ACID in place of glucuronic acid, its epimer, at carbon atom 5. (from Merck, 12th ed)	Chondroitin Sulfate B,beta-Heparin,Sulfate B, Chondroitin,Sulfate, Dermatan,beta Heparin
D004305	Dose-Response Relationship, Drug	The relationship between the dose of an administered drug and the response of the organism to the drug.	Dose Response Relationship, Drug,Dose-Response Relationships, Drug,Drug Dose-Response Relationship,Drug Dose-Response Relationships,Relationship, Drug Dose-Response,Relationships, Drug Dose-Response
D006495	Heparin, Low-Molecular-Weight	Heparin fractions with a molecular weight usually between 4000 and 6000 kD. These low-molecular-weight fractions are effective antithrombotic agents. Their administration reduces the risk of hemorrhage, they have a longer half-life, and their platelet interactions are reduced in comparison to unfractionated heparin. They also provide an effective prophylaxis against postoperative major pulmonary embolism.	LMWH,Low-Molecular-Weight Heparin,Low Molecular Weight Heparin,Heparin, Low Molecular Weight
D006629	Hirudins	Single-chain polypeptides of about 65 amino acids (7 kDa) from LEECHES that have a neutral hydrophobic N terminus, an acidic hydrophilic C terminus, and a compact, hydrophobic core region. Recombinant hirudins lack tyr-63 sulfation and are referred to as 'desulfato-hirudins'. They form a stable non-covalent complex with ALPHA-THROMBIN, thereby abolishing its ability to cleave FIBRINOGEN.	Hirudin
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D014914	Whole Blood Coagulation Time	The time required by whole blood to produce a visible clot.	Activated Coagulation Time, Whole Blood,Blood Coagulation Time, Whole,Coagulation Time, Whole Blood
D065427	Factor Xa Inhibitors	Endogenous factors and drugs that inhibit or block the activity of FACTOR XA.	Direct Factor Xa Inhibitor,Direct-Acting Oral Anticoagulant,Direct-Acting Oral Anticoagulants,Factor Xa Inhibitor,Direct Factor Xa Inhibitors,Anticoagulant, Direct-Acting Oral,Anticoagulants, Direct-Acting Oral,Direct Acting Oral Anticoagulant,Direct Acting Oral Anticoagulants,Inhibitor, Factor Xa,Oral Anticoagulant, Direct-Acting,Oral Anticoagulants, Direct-Acting,Xa Inhibitor, Factor