The effect of two arginine-specific cysteine proteinases (gingipains R) from Porphyromonas gingivalis, an aetiological factor of adult periodontitis, on the activation of human factor IX was investigated in the presence of ethylene glycol, an activity enhancer of activated factor IX (factor IXa), with the use of a fluorogenic oligopeptide substrate. Each gingipain R rapidly activated factor IX ...

As an approach to the study of structure-function relationships in the normal and defective forms of human coagulation factor IX, we have begun to develop a series of monoclonal antibodies against specific sites on the protein. Zymogen and activated forms of normal factor IX were used initially as antigen for the preparation of monoclonal antibodies. Recombinant phage were prepared by cloning s...

Coagulation studies were performed on haemophilic patients during a controlled trial of oral contraceptive therapy. Treatment with a combined oestrogen-progestogen preparation was associated with a significant rise in the factor VII-X complex. This change was not observed during treatment with progestogen alone. The highest levels of factor IX and fibrinogen and the lowest levels of factor X we...

An infant with a severe deficiency of factor X presened in the neonatal period with uncontrollable bleeding from heel prick sites, spontaneous bruising, and haematoma. The deficiency was controlled by infusions of dried human factors II, IX, and X concentrate; the half-life of the infused factor X material is only 18 hours. Despite prophylactic weekly infusions of factor X concentrate, the chil...

Molecular genetic details of the human coagulation system were among the first successes of the genetic revolution in the 1980s. This information led to new molecular diagnostic strategies for inherited disorders of hemostasis and the development of recombinant clotting factors for the treatment of the common inherited bleeding disorders. A longer term goal of this knowledge has been the establ...

objective: electroporation is the most common method used for the transfection of dna. although this method has been attributed for various cell using different buffer compositions, the effects of dna concentration on the transfection efficiency has not yet been studied. here the correlation between the efficiency of electroporation reaction and increments of dna concentration has been investig...

Haemophilia is a rare and congenital bleeding disorder caused by a genetic defect, resulting in a lack of or insufficient coagulation factors VIII or IX in the body. In affected individuals, this causes an inability to clot blood, leading to bleeds in the joints, muscles and soft tissues. If left untreated, this can lead to disability and sometimes death. It is widely agreed that the optimal st...