Factor XIII: A fibrin-stabilizing plasma enzyme (TRANSGLUTAMINASES) that is activated by THROMBIN and CALCIUM to form FACTOR XIIIA. It is important for stabilizing the formation of the fibrin polymer (clot) which culminates the coagulation cascade.Factor XIII Deficiency: A deficiency of blood coagulation FACTOR XIII or fibrin stabilizing factor (FSF) that prevents blood clot formation and results in a clinical hemorrhagic diathesis.Factor XIIIa: Activated form of FACTOR XIII, a transglutaminase, which stabilizes the formation of the fibrin polymer (clot) culminating the blood coagulation cascade.Transglutaminases: Transglutaminases catalyze cross-linking of proteins at a GLUTAMINE in one chain with LYSINE in another chain. They include keratinocyte transglutaminase (TGM1 or TGK), tissue transglutaminase (TGM2 or TGC), plasma transglutaminase involved with coagulation (FACTOR XIII and FACTOR XIIIa), hair follicle transglutaminase, and prostate transglutaminase. Although structures differ, they share an active site (YGQCW) and strict CALCIUM dependence.Collagen Type XIII: A non-fibrillar collagen found as a ubiquitously expressed membrane- associated protein. Type XIII collagen contains both collagenous and non-collagenous domains along with a transmembrane domain within its N-terminal region.Fibrin: A protein derived from FIBRINOGEN in the presence of THROMBIN, which forms part of the blood clot.Fibrinogen: Plasma glycoprotein clotted by thrombin, composed of a dimer of three non-identical pairs of polypeptide chains (alpha, beta, gamma) held together by disulfide bonds. Fibrinogen clotting is a sol-gel change involving complex molecular arrangements: whereas fibrinogen is cleaved by thrombin to form polypeptides A and B, the proteolytic action of other enzymes yields different fibrinogen degradation products.Cadaverine: A foul-smelling diamine formed by bacterial decarboxylation of lysine.Batroxobin: A proteolytic enzyme obtained from the venom of fer-de-lance (Bothrops atrox). It is used as a plasma clotting agent for fibrinogen and for the detection of fibrinogen degradation products. The presence of heparin does not interfere with the clotting test. Hemocoagulase is a mixture containing batroxobin and factor X activator. EC 3.4.21.-.alpha-2-Antiplasmin: A member of the serpin superfamily found in plasma that inhibits the lysis of fibrin clots which are induced by plasminogen activator. It is a glycoprotein, molecular weight approximately 70,000 that migrates in the alpha 2 region in immunoelectrophoresis. It is the principal plasmin inactivator in blood, rapidly forming a very stable complex with plasmin.Coagulants: Agents that cause clotting.Thrombelastography: Use of a thrombelastograph, which provides a continuous graphic record of the physical shape of a clot during fibrin formation and subsequent lysis.Dansyl Compounds: Compounds that contain a 1-dimethylaminonaphthalene-5-sulfonyl group.Bentonite: A colloidal, hydrated aluminum silicate that swells 12 times its dry size when added to water.Thrombin: An enzyme formed from PROTHROMBIN that converts FIBRINOGEN to FIBRIN.Blood Coagulation: The process of the interaction of BLOOD COAGULATION FACTORS that results in an insoluble FIBRIN clot.Blood Coagulation Disorders: Hemorrhagic and thrombotic disorders that occur as a consequence of abnormalities in blood coagulation due to a variety of factors such as COAGULATION PROTEIN DISORDERS; BLOOD PLATELET DISORDERS; BLOOD PROTEIN DISORDERS or nutritional conditions.Ficain: A sulfhydryl proteinase with cysteine at the active site from ficus latex. Preferential cleavage is at tyrosine and phenylalanine residues. EC 184.108.40.206.Blood Coagulation Tests: Laboratory tests for evaluating the individual's clotting mechanism.Digestive System Diseases: Diseases in any part of the GASTROINTESTINAL TRACT or the accessory organs (LIVER; BILIARY TRACT; PANCREAS).