Linked Life Data

1771408

Source:http://linkedlifedata.com/resource/pubmed/id/1771408

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1992-2-21
pubmed:abstractText
Several laboratory methods are available to measure r-hirudin, including clot-based, amidolytic, immunologic, and physicochemical techniques. The global tests, such as the PT, APTT, and Heptest, did not show an adequate response to r-hirudin in the range of 0.5 to 10.0 micrograms/ml, where full anticoagulation is achieved, as determined by animal models of thrombosis. The 10 U/ml thrombin time assay was very sensitive to r-hirudin, whereas the 10 U/ml calcium thrombin time gave a dose-dependent response from 0.15 to 10.0 micrograms/ml. Whole blood clotting assays (ACT, TEG) effectively measured r-hirudin levels up to 25 micrograms/ml. The amidolytic anti-Factor IIa assay, specific for evaluating direct thrombin inhibition, was very effective, particularly when modified to decrease the sample: thrombin ratio for higher r-hirudin concentrations. This assay may be useful in quality control, since it is biochemically defined and reagents are easily standardized. Thrombin generation assays based on synthetic substrates showed limited effect of r-hirudin; however, assays based on TAT complex and prothrombin fragment F1+2 generation showed a dose-dependent response. Immunologic methods (ELISA) are under development. Since these assays measure both complexed and noncomplexed hirudin, and since they are only sensitive to submicrogram levels, they may only be useful for the direct quantitation of absolute levels of r-hirudin but not for monitoring clinical anticoagulation. Thus, thrombin-based clotting, amidolytic, and immunologic assays can be used to evaluate and measure r-hirudin. However, optimization of each assay to respond to high and low concentrations of r-hirudin and their application to clinical monitoring, batch control, and standardization needs to be determined.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0094-6176
pubmed:author
pubmed:issnType
Print
pubmed:volume
17
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
103-12
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Comparative studies on various assays for the laboratory evaluation of r-hirudin.
pubmed:affiliation
Department of Thoracic Cardiovascular Surgery, Loyola University Medical Center, Maywood, Illinois 60153.
pubmed:publicationType
Journal Article, Comparative Study