Influence of different levels of heparin and antithrombin Ⅲ on human coagulation factor Ⅸ activity / 中国输血杂志

【Objective】 To study the effect of different concentrations of heparin, ATⅢ or a mixture of heparin and antithrombin Ⅲ (ATⅢ) (1∶1)on the activity of human coagulation factor Ⅸ (FⅨ). 【Methods】 The heparin or heparin/ATⅢ with different concentrations were added into human coagulation Ⅸ products or human prothrombin complex (PCC) to prepare heparin or heparin/ATⅢ samples, containing 0, 0.1, 0.3, 0.5, 0.8, 1, 2 and 4 IU per unit. ATⅢ with different concentrations were added into FⅨ or PCC to prepare ATⅢ samples containing ATⅢ 0, 0.1, 0.5 and 1 IU per unit. The FⅨ activity of the samples prepared was tested by one-stage coagulation method. Then corresponding amount of protamine sulfate were added to neutralize heparin or heparin/ATⅢ to detect the FⅨ activity again. Their influence of heparin, ATⅢ and heparin/ATⅢ with different concentrations on the activity of FⅨ were analyzed. 【Results】 When the content of heparin or heparin/ATⅢ was 0, 0.1, 0.3 and 0.5 IU per unit of FⅨ, the detection results of FⅨ titer in samples were consistent. When the content of heparin or heparin/ATⅢ per unit of FⅨ was 0.8, 1, 2 and 4 IU, the detection results of FⅨ titer were all lower than those of samples without heparin. When the ATⅢ content was 0, 0.1, 0.5 and 1 IU, the FⅨ titer of the samples was consistent. 【Conclution】 When the content of heparin or heparin/ATⅢ in the product is less than or equal to 0.5 IU per IU of FⅨ, the step of protamine sulfate adding could be omitted as it has little effect on FⅨ activity. When >0.5 IU per IU of FⅨ, however, protamine sulfate adding, to neutralize heparin, is necessary before FⅨ activity testing.

Human coagulation factor VIII domain-specific recombinant polypeptide expression

BACKGROUND: Hemophilia A is caused by heterogeneous mutations in F8. Coagulation factor VIII (FVIII), the product of F8, is composed of multiple domains designated A1-A2-B-A3-C1-C2. FVIII is known to interact with diverse proteins, and this characteristic may be important for hemostasis. However, little is known about domain-specific functions or their specific binding partners. METHODS: To determine F8 domain-specific functions during blood coagulation, the FVIII domains A1, A2, A3, and C were cloned from Hep3B hepatocytes. Domain-specific recombinant polypeptides were glutathione S-transferase (GST)- or polyhistidine (His)-tagged, over-expressed in bacteria, and purified by specific affinity chromatography. RESULTS: Recombinant polypeptides of predicted sizes were obtained. The GST-tagged A2 polypeptide interacted with coagulation factor IX, which is known to bind the A2 domain of activated FVIII. CONCLUSION: Recombinant, domain-specific polypeptides are useful tools to study the domain-specific functions of FVIII during the coagulation process, and they may be used for production of domain-specific antibodies.

Anesthetic Management of a Patient with Hemophilia B / 대한마취과학회지

A 22 year old male with hemophilia B was scheduled for the correction of a right subtrochanteric femur fracture. Plasma concentration of coagulation factor IX in this patient was 50% of the normal level and the partial thromboplastin time was 57 seconds on the first day of hospital administration. We started the intravenous administration of facnyne injection (factor IX) 11 days before the operation when his plasma concentration was 20%. His plasma concentration was 40% on the operation day. The operation and general anesthesia were accomplished safely without severe hemorrhage or major complication. He received facnyne injection continuously until the 5th postoperative day: 25-43% of his plasma concentrations of factor IX was maintained. He had no problem with postoperative care.

RFLP Analysis of a Gene for Blood Coagulation Factor IX in Korean / 대한산부인과학회잡지

OBJECTIVE: The purpose of this study was to investigate the methods for analysis of restriction fragment length polymorphisms of hemophilia B (coagulation factorIX) gene in Korean population. METHODS: Genomic DNAs were extracted from 40 Korean females. In order to amplify genomic DNAs at the region of the polymorphic sites, two sets of primers (Hha I and Dde I) were synthesized. The primers were named as FIX1, FIX2 for Hha I, and Dde I 59, Dde I 39 for Dde I, respectively. Hha I primers annealed 3'-flanking region of the FactorIX gene and amplified 230 bp long fragment. The PCR fragment (230 bp) treated with Hha I endonuclease produced two fragments (150 bp and 80 bp), when the polymorphic site existed. Dde I primers annealed the region of the first intron of Factor IX gene and amplified 319 bp long fragments. People cases with Dde I polymorphic site are supposed to produce 369 bp long fragment. Results: It has been found that seven (14 X chromosomes) out of forty individuals showed Hha I polymorphism. However, none of the experimental People cases showed the Dde I polymorphism. CONCLUSIONS: By the analysis of 80 chromosomes, the PICs calculated from allele frequency of Hha I-RFLP (0.175/0.825) and that of Dde I-RFLP (0.0/1.0) were 0.289=[1-(0.1752+0.8252)] and 0=[1-(02+12)], respectively. From these results, it can be postulated that Hha I and Dde I polymorphisms of the Factor IX gene in Korean exhibited different patterns from those of Caucasian.