Biomaterial Database

Demonstration and mode of action of an inhibitor for activated Hageman factor (factor XIIa) of the intrinsic blood coagulation pathway from Schistosoma mansoni. 1977

V C Tsang, and R T Damian

An anticoagulant activity from adult Schistosoma mansoni whole worm homogenate is described. The inhibitor appears to be specific for the contact activation step of the intrinsic pathway. Experiments with both human and mouse plasmas have defined the specificity of the inhibitor as follows: (1) It lengthens the partial thromboplastin time of normal plasma. (2) It has no effect on the prothombin time and Russell's viper venom time of normal plasma. (3) Preactivation of normal plasma by a contact activator such as Celite eliminates essentially all inhibitory activity. (4) The inhibitor appears to be heat stable and can be precipitated by centrifugation above 27,000 g. (5) The inhibitor has no effect on the activation of factor XII by Celite. (6) The activation of factor XI by factor XIIa, however, is inhibited by the schistosomal inhibitor. The above data are consistent with the view that S. mansoni adults possess an anticoagulant that is capable of specifically inhibiting the conversion of factor XI to factor XIa by factor XIIa.

UI	MeSH Term	Description	Entries
D001780	Blood Coagulation Tests	Laboratory tests for evaluating the individual's clotting mechanism.	Coagulation Tests, Blood,Tests, Blood Coagulation,Blood Coagulation Test,Coagulation Test, Blood,Test, Blood Coagulation
D002836	Hemophilia B	A deficiency of blood coagulation factor IX inherited as an X-linked disorder. (Also known as Christmas Disease, after the first patient studied in detail, not the holy day.) Historical and clinical features resemble those in classic hemophilia (HEMOPHILIA A), but patients present with fewer symptoms. Severity of bleeding is usually similar in members of a single family. Many patients are asymptomatic until the hemostatic system is stressed by surgery or trauma. Treatment is similar to that for hemophilia A. (From Cecil Textbook of Medicine, 19th ed, p1008)	Christmas Disease,Factor IX Deficiency,Deficiency, Factor IX,F9 Deficiency,Haemophilia B,Hemophilia B Leyden,Hemophilia B(M),Plasma Thromboplastin Component Deficiency,Bs, Hemophilia,Deficiencies, F9,Deficiencies, Factor IX,Deficiency, F9,Disease, Christmas,F9 Deficiencies,Factor IX Deficiencies,Haemophilia Bs,Hemophilia Bs,Hemophilia Bs (M)
D005172	Factor XI	Stable blood coagulation factor involved in the intrinsic pathway. The activated form XIa activates factor IX to IXa. Deficiency of factor XI is often called hemophilia C.	Coagulation Factor XI,Plasma Thromboplastin Antecedent,Blood Coagulation Factor XI,Factor 11,Factor Eleven,Antecedent, Plasma Thromboplastin,Factor XI, Coagulation,Thromboplastin Antecedent, Plasma
D005173	Factor XI Deficiency	A hereditary deficiency of blood coagulation factor XI (also known as plasma thromboplastin antecedent or PTA or antihemophilic factor C) resulting in a systemic blood-clotting defect called hemophilia C or Rosenthal's syndrome, that may resemble classical hemophilia.	Hemophilia C,Rosenthal Syndrome,Deficiency, Factor 11,Deficiency, Factor Eleven,Deficiency, Factor XI,Factor 11 Deficiency,Factor Eleven Deficiency,Plasma Thromboplastin Antecedent Deficiency,Rosenthal's Syndrome,Deficiencies, Factor 11,Deficiencies, Factor Eleven,Deficiencies, Factor XI,Factor 11 Deficiencies,Factor Eleven Deficiencies,Factor XI Deficiencies,Rosenthal Syndromes,Rosenthal's Syndromes,Rosenthals Syndrome,Syndrome, Rosenthal,Syndrome, Rosenthal's
D005174	Factor XII	Stable blood coagulation factor activated by contact with the subendothelial surface of an injured vessel. Along with prekallikrein, it serves as the contact factor that initiates the intrinsic pathway of blood coagulation. Kallikrein activates factor XII to XIIa. Deficiency of factor XII, also called the Hageman trait, leads to increased incidence of thromboembolic disease. Mutations in the gene for factor XII that appear to increase factor XII amidolytic activity are associated with HEREDITARY ANGIOEDEMA TYPE III.	Coagulation Factor XII,Hageman Factor,Factor 12,Factor Twelve
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D000925	Anticoagulants	Agents that prevent BLOOD CLOTTING.	Anticoagulant Agent,Anticoagulant Drug,Anticoagulant,Anticoagulant Agents,Anticoagulant Drugs,Anticoagulation Agents,Indirect Thrombin Inhibitors,Agent, Anticoagulant,Agents, Anticoagulant,Agents, Anticoagulation,Drug, Anticoagulant,Drugs, Anticoagulant,Inhibitors, Indirect Thrombin,Thrombin Inhibitors, Indirect
D012550	Schistosoma mansoni	A species of trematode blood flukes of the family Schistosomatidae. It is common in the Nile delta. The intermediate host is the planorbid snail. This parasite causes schistosomiasis mansoni and intestinal bilharziasis.	Schistosoma mansonus,mansonus, Schistosoma
D012911	Snakes	Limbless REPTILES of the suborder Serpentes.	Serpentes,Ophidia,Snake