We report the case of a 60-year-old man with mild Christmas disease, Factor IX 10% of normal, who developed chronic hepatitis C infection after receiving coagulation factor concentrates. Subsequently he developed encephalopathy and liver failure and was referred for liver transplantation. Following transplantation, Factor IX levels rapidly normalised and have remained so, representing a phenoty...

Tissue factor is the major initiator of coagulation. Both factor IX and factor X are activated by the complex of factor VIIa and tissue factor (VIIa/TF). The goal of this study was to determine the specific roles of factors IXa and Xa in initiating coagulation. We used a model system of in vitro coagulation initiated by VIIa/TF and that included unactivated platelets and plasma concentrations o...

Haemophilia is a congenital coagulation defect brought about by the deficiency or lack of coagulation factor IX. The prevalence of coronary artery disease and acute coronary syndrome (ACS) is lower among haemophiliacs than in the normal population. However, with the administration of factor concentrate, average life expectancy can now extend to as long as 70 years in patients with haemophilia, ...

  Background: Factor VII concentrates are used in patients with congenital or acquired factor VII deficiency or treatment of hemophilia patients with inhibitors. In this research, immunoaffinity chromatography was used to purify factor VII from prothrombin complex (Prothrombin-Proconvertin-Stuart Factor-Antihemophilic Factor B or PPSB) which contains coagulation factors II, VII, IX and X. The a...

OBJECTIVE Previous work has shown that platelets stimulated with the combination of thrombin and convulxin, a glycoprotein VI agonist, develop 2 populations with different levels of alpha-granule factor V bound to the platelet surface. To evaluate whether this phenomenon is restricted to alpha-granule components or is a feature that can be generalized to other coagulation factors, we studied th...

Studies of the mechanisms of blood coagulation zymogen activation demonstrate that exosites (sites on the activating complex distinct from the protease active site) play key roles in macromolecular substrate recognition. We investigated the importance of exosite interactions in recognition of factor IX by the protease factor XIa. Factor XIa cleavage of the tripeptide substrate S2366 was inhibit...

Background:  Human coagulation factor IX (hFIX) is a glycoprotein with two N-glycosylation sites at the activation peptide. Since the activation peptide is removed in mature hFIX, the exact role of N-glycosylation is unclear. To investigate the role of N-glycosylation in the secretion and activity of hFIX, we inhibited N-glycosylation by tunicamycin in the stable Human Embryonic Kidney (HEK)- c...

Hemophilia B is a rare blood coagulation disorder. Complications such as bleeding and hematoma can cause necrosis of flaps, wound disruption, and the disturbance of wound healing. In particular, guidelines for flap operations in hemophilia B patients have still not been defined, and case reports are rare. We reconstructed the heel of a 41-year-old male hemophilia B patient using a reverse sural...

background: heterogeneous mutations in the human coagulation factor ix gene lead to an x-linked recessive bleeding disorder known as hemophilia b. the disease is distributed worldwide with no ethnic or geographical priority. materials and methods: the aim of this study was to characterize the factor ix gene mutations in 28 unrelated iranian hemophilia b patients. polymerase chain reaction (pcr)...

The majority of cases of human hemophilia B are the result of missense mutations in the coagulation factor IX gene and defective circulating factor IX is detectable in most patients. The available mouse factor IX knockout models of hemophilia B (FIXKO mouse) reproduce the bleeding phenotype of human hemophilia B, but because the models produce no factor IX they fail to reproduce the dominant hu...