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FV Gene (fv + gene)

Distribution by Scientific Domains

Medical Sciences	75%

Selected Abstracts

Factor V deficiency: a concise review

HAEMOPHILIA, Issue 6 2008
J. N. HUANG
Summary., Factor V (FV; proaccelerin or labile factor) is the plasma cofactor for the prothrombinase complex that activates prothrombin to thrombin. FV deficiency can be caused by mutations in the FV gene or in genes encoding components of a putative cargo receptor that transports FV (and factor VIII) from the endoplasmic reticulum to the Golgi. Because FV is present in platelet ,-granules as well as in plasma, low FV levels are also seen in disorders of platelet granules. Additionally, acquired FV deficiencies can occur in the setting of rheumatologic disorders, malignancies, and antibiotic use and, most frequently, with the use of topical bovine thrombin. FV levels have limited correlation with the risk of bleeding, but overall, FV-deficient patients appear to have a less severe phenotype than patients with haemophilia A or B. The most commonly reported symptoms are bleeding from mucosal surfaces and postoperative haemorrhage. However, haemarthroses and intramuscular and intracranial haemorrhages can also occur. Because no FV-specific concentrate is available, fresh frozen plasma remains the mainstay of treatment. Antifibrinolytics can also provide benefit, especially for mucosal bleeding. In refractory cases, or for patients with inhibitors, prothrombin complex concentrates, recombinant activated FVIIa, and platelet transfusions have been successfully used. Some patients with inhibitors may also require immunosuppression. [source]

Inherited defects of coagulation factor V: the hemorrhagic side

JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 1 2006
R. ASSELTA
Summary., Coagulation factor V (FV) is the protein cofactor required in vivo for the rapid generation of thrombin catalyzed by the prothrombinase complex. It also represents a central regulator in the early phases of blood clot formation, as it contributes to the anticoagulant pathway by participating in the downregulation of factor VIII activity. Conversion of precursor FV to either a procoagulant or anticoagulant cofactor depends on the local concentration of procoagulant and anticoagulant enzymes, so that FV may be regarded as a daring tight-rope walker gently balancing opposite forces. Given this dual role, genetic defects in the FV gene may result in opposite phenotypes (hemorrhagic or thrombotic). Besides a concise description on the structural, procoagulant and anticoagulant properties of FV, this review will focus on bleeding disorders associated with altered levels of this molecule. Particular attention will be paid to the mutational spectrum of type I FV deficiency, which is characterized by a remarkable genetic heterogeneity and by an uneven distribution of mutations throughout the FV gene. [source]

Factor V I359T: a novel mutation associated with thrombosis and resistance to activated protein C

BRITISH JOURNAL OF HAEMATOLOGY, Issue 3 2003
A. D. Mumford
Summary. We report a kindred in which two siblings suffered spontaneous venous thromboses in the second decade of life. Further investigation showed reduced coagulation factor V (FV) activity and activated protein C resistance (APCR) ratio but no other thrombophilic abnormalities. The reduction in APCR ratio persisted in a modified APCR assay in which FV activity was normalized between test and control plasmas. Analysis of the FV gene showed that the thrombotic individuals had a complex genotype that included two novel point mutations c.529G>T and c.1250T>C resulting in FV E119X and FV I359T substitutions inherited on different alleles. Individuals in the kindred with FV E119X or FV I359T substitutions alone were asymptomatic. We suggest that the FV I359T substitution confers pro-thrombotic risk and APCR, but that this is only clinically manifest when co-inherited with the FV E119X allele. The FV I359T substitution creates a new consensus sequence for N-linked glycosylation within the FV heavy chain and we speculate that this abnormal glycosylation may disrupt activated protein C-mediated proteolysis of the variant FV and FVa. [source]

Cloning, expression, and identification of anti-carbofuran single chain Fv gene

BIOTECHNOLOGY PROGRESS, Issue 4 2009
Hong Wang
Abstract Phage display method was used to clone anti-carbofuran (CBF) single chain Fv (scFv) gene. The heavy chain and light chain variable region genes were amplified by the polymerase chain reaction from the CBF-specific hybridoma cell lines 5D3 and assembled as a scFv DNA fragment with linker peptide (Gly4Ser)3. The scFv DNA fragment was cloned into M13 phagemid vector pCANTAB5E and the anti-CBF antibody libraries were then constructed. After one round of panning with CBF-ovalbumin (CBF-OVA) as a conjugate, antigen-binding positive recombinant phage clones were successfully selected by enzyme-linked immunosorbent assay (ELISA). The positive phages were used to infect Escherichia coli HB2151 cells and the expression of the soluble scFv antibodies was then induced by IPTG. The scFv antibody was about 31 kDa by SDS-PAGE and showed HRP-anti-E-tag antibody-recognized activity by Western blotting. The indirect competitive ELISA (icELISA) showed that the recombinant scFv antibody could competitively combine with CBF, with the IC50 value of 1.07 ng/mL. The cross reactivity studies showed that the anti-CBF scFv antibody, similar to the parent monoclonal antibody, poses high specificity to CBF and has little reactivity to the analogs. Taken together, these findings suggest that the recombinant scFv antibody can be used for further developing immunoassay method for CBF. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 [source]