China
Africa
Explore chapters and articles related to this topic
Defects in Coagulation Factors Leading to Recurrent Pregnancy Loss
Published in Howard J.A. Carp, Recurrent Pregnancy Loss, 2020
Coagulation factor XIII (FXIII) is plasma transglutaminase that participates in the final step of the coagulation cascade. Following activation by thrombin the active form—FXIIIa—cross-links fibrin chains through γ-glutamyl-ε-lysine bonds, creating a stable clot resistant to fibrinolysis. In plasma, FXIII circulates as a heterotetramer (A2B2) composed of two catalytic A subunits (FXIII-A) and two carrier B subunits (FXIII-B) [2].
Transglutaminases
Published in Elling Kvamme, Glutamine and Glutamate in Mammals, 1988
TG has been purified from the guinea pig liver, human epidermis, and guinea pig hair follicle and the molecular weights of the monomeric forms are 75, 55, and 27 kdaltons, respectively. In addition, human plasma and platelet coagulation factor XIII have been purified. Factor XIII is a proenzyme (zymogen) which is converted to active TG (factor XHIa) upon incubation with thrombin. The plasma factor XIII is a tetramer (molecular weight —300 kdaltons) containing a pair of catalytically active α-chains (molecular weight 75 kdaltons) and a pair of nonactive b-chains (molecular weight 80 kdaltons). The platelet factor XIII (molecular weight 150 kdaltons) contains two α-chains.
t-PA in Fibrin Dissolution and Hemostasis
Published in Cornelis Kluft, Tissue-Type Plasminogen Activator (t-PA): Physiological and Clinical Aspects, 1988
Figure 3 summarizes in a schematic activation pathway the components of fibrinolysis considered in this paragraph. Besides the activation of plasminogen by t-PA (route a) also two other routes (b,c) containing plasminogen proactivators are indicated. These intrinsic routes of plasminogen activation concern the contribution of pro-u-PA (route c) and of plasminogen proactivator activated by the factor XII-process (route b) (reviewed in Reference 46). Further indicated in the scheme is the contribution of leukocytic enzymes, notably elastase, in degrading fibrin. The various inhibitors and non-enzymatic factors are placed in the figure at their major place of action. The covalent cross-linking of α2-antiplasmin, fibronectin, and thrombospondin to fibrin through the action of activated coagulation factor XIII is separately noted. More detailed introduction of factors and interactions indicated in Figure 3 will emerge further in the text of the following paragraph and in Chapter 10 of this volume.47
A gottingen minipig model of radiation-induced coagulopathy
Published in International Journal of Radiation Biology, 2021
Karla D. Thrall, Saikanth Mahendra, M. Keven Jackson
Comparison of average change in coagulation factor activity levels from baseline following irradiation was compared between surviving animals and decedents. The greatest differences between these subsets of animals were observed with factors XIII (Figure 8(a)), XII (Figure 8(b)), protein C (Figure 8(c)) and antiplasmin (Figure 8(d)). The difference between coagulation factor XIII levels between surviving animals and decedents was statistically significant at post irradiation Day 20. Regardless of statistical significance, with the exception of antiplasmin, the trend indicates coagulation factor activity levels for VII, XII, XIII, and protein C decrease as the animal approaches moribund condition. Interestingly, average activity levels of factor XII observed in decedents appear to decrease as early as post irradiation Day 4. In contrast, average antiplasmin activity levels increased in decedents compared to surviving animals, possibly indicative of a fibrinolytic shutdown.
Potent Hemostatic Efficacy of a Novel Recombinant Fibrin Sealant Patch (KTF-374) in Rabbit Bleeding Models
Published in Journal of Investigative Surgery, 2019
Sumika Miyabashira (Tanaka), Takayuki Imamura, Miho Fujimoto, Akitoshi Ohno, Tsunefumi Kobayashi, Noriko Shinya
KTF-374 consists of two layers, a fibrinogen layer and a thrombin layer. The fibrinogen layer is applied to the bleeding site. Because the fibrinogen layer is highly soluble and promptly dissolves upon application, it may increase the local concentration of fibrinogen at the active surface. This is thought to react with thrombin that flows down from the thrombin layer, producing a fibrin clot with high hemostatic efficacy. This hypothesis is supported by the finding by Shinya et al. that fibrin sealants have strong adhesive properties when fibrinogen solution is rubbed into the site of application.14 The adhesion between fibrinogen and tissue is increased by binding of adhesive glycoproteins,15 thus enhancing the tissue-anchoring effect of fibrin sealant. Meanwhile, the formation of cross-linked fibrinogen γ-chain was observed in SDS-PAGE analysis performed after dissolution of the fibrin clot formed after application of KTF-374 to porcine blood (data not shown). Although KTF-374 does not contain coagulation factor XIII, it likely reacted with coagulation factor XIII in the blood of the laboratory animals to form cross-linked fibrinogen and fibrin gel.
Tocilizumab treatment in patients with rheumatoid arthritis is associated with reduced fibrinogen levels and increased blood loss after total knee arthroplasty
Published in Modern Rheumatology, 2018
Hitoshi Imamura, Shigeki Momohara, Koichiro Yano, Yu Sakuma, Masanori Nakayama, Haruki Tobimatsu, Katsunori Ikari
Our study has some limitations. First, our study was retrospective, non-randomized, and included a small number of patients. In addition, we enrolled patients with RA who had been tested for pre-operative fibrinogen values only by chance. Second, the volume of estimated blood loss, which we defined as the volume of bleeding, is only an estimated value, and might not be an accurate reflection of the volume of bleeding. Third, TCZ has been reported to be closely associated with an increased risk for hemorrhage in patients with RA in studies focusing on coagulation factor XIII [2–4]; we did not test for any association between factor XIII and perioperative bleeding, because factor XIII assays from plasma samples are not routinely performed at our institution before TKA surgery.