Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.55 (PTR)
 433 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The prothrombin time is the coagulation time of citrated plasma in the presence of calcium and a tissue extract, thromboplastin, added in excess. The prothrombin time was historically the first method of evaluation and control of oral anticoagulation. Over the years, the different thromboplastins have changed, diversified, so affecting the result of the prothrombin ration established from the prothrombin time and a reference curve. In 1985, the International Committee on Thrombosis and Haemostasis requested that all the losts of thromboplastin have their international sensitivity index (ISI) indicated. This allowed uniformity of the results by the introduction of the INR (International Normalized Ratio) calculated by the formula: INR = (PTR)ISI, the PTR or prothrombin time ratio corresponding to the patients' prothrombin time divided by that of reference control plasma. It is, in fact, impossible to interpret the results of a prothrombin ration without knowing their expression in INR. The consequences of the absence of uniformity in the control of anticoagulant therapy are important and serious. The uncertainty concerning the degree of anticoagulation inherent in the use of a single prothrombin ratio may be the source of bleeding or thromboembolic complications. Curiously, the system based on the INR is neither generalised, nearly 10 years after its recommendation, nor adopted by the majority of practitioners. However, the stakes are high because the principal complication of oral anticoagulants remains bleeding, including the dramatic strokes. Moreover, the global mortality due to haemorrhagic complications is about 0.1 to 0.5% for treatments of short duration and much higher in prolonged therapy.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Current biological surveillance of oral anticoagulant treatment]. 764 54

The superfamily of proteins containing C-type lectin-like domains (CTLDs) is a large group of extracellular Metazoan proteins with diverse functions. The CTLD structure has a characteristic double-loop ('loop-in-a-loop') stabilized by two highly conserved disulfide bridges located at the bases of the loops, as well as a set of conserved hydrophobic and polar interactions. The second loop, called the long loop region, is structurally and evolutionarily flexible, and is involved in Ca2+-dependent carbohydrate binding and interaction with other ligands. This loop is completely absent in a subset of CTLDs, which we refer to as compact CTLDs; these include the Link/PTR domain and bacterial CTLDs. CTLD-containing proteins (CTLDcps) were originally classified into seven groups based on their overall domain structure. Analyses of the superfamily representation in several completely sequenced genomes have added 10 new groups to the classification, and shown that it is applicable only to vertebrate CTLDcps; despite the abundance of CTLDcps in the invertebrate genomes studied, the domain architectures of these proteins do not match those of the vertebrate groups. Ca2+-dependent carbohydrate binding is the most common CTLD function in vertebrates, and apparently the ancestral one, as suggested by the many humoral defense CTLDcps characterized in insects and other invertebrates. However, many CTLDs have evolved to specifically recognize protein, lipid and inorganic ligands, including the vertebrate clade-specific snake venoms, and fish antifreeze and bird egg-shell proteins. Recent studies highlight the functional versatility of this protein superfamily and the CTLD scaffold, and suggest further interesting discoveries have yet to be made.
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PMID:The C-type lectin-like domain superfamily. 1633 59