Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Factor VII Deficiency”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 757 records · Page 42Linked to original sources

Involvement of platelet membrane glycoprotein Ib and glycoprotein IIb/IIIa complex in thrombin-dependent and -independent platelet aggregations induced by tumor cells.

Involvement of platelet membrane glycoproteins (GP) in interactions between platelets and tumor cells was studied by using two human tumor cell lines and two monoclonal antibodies against platelet membrane GP. HMV-I cells derived from vaginal melanoma induced platelet aggregation in heparinized plasma, which was not followed by coagulation. M7609 cells derived from colon adenocarcinoma also induced platelet aggregation in heparinized plasma, which, on the contrary, was followed by coagulation. Aggregating activities of the HMV-I cells were abolished by pretreatment with neuraminidase or trypsin, but M7609 activity was not labile to these enzymes. Aggregations induced by M7609 were inhibited by hirudin or MD805, while those by HMV-I were not. M7609 cells dose dependently shortened the recalcification time of normal as well as Factor IX-deficient plasmas, while they were not effective in shortening the time of Factor II- or Factor VII-deficient plasmas. The procoagulant activity of HMV-I cells was 1000 times less than M7609 on the basis of cell numbers. When human platelets were preincubated with monoclonal anti-GPIb or anti-GPIIb/IIIa complex antibodies, neither cell line could cause aggregations. These findings suggest that both GPIb and the GPIIb/IIIa complex on the platelet surface are involved in the thrombin-dependent and -independent platelet aggregations induced by tumor cells.

Adenocarcinoma↗

Gene targeting in hemostasis. Factor VII.

Factor VII (FVII), in concert with its natural cofactor and receptor, Tissue Factor (TF), initiates the process of blood coagulation following vascular injury. Mice completely deficient in FVII were generated via specific deletion of exons 2 to 8, thus deleting the entire coding region of the mature protein. In contrast to the early lethality observed in TF-deficient embryos (TF-/-), embryos deficient in FVII (FVII-/-) developed normally, without incidence of hemorrhage. However, FVII-/- neonates succumbed to either early intraabdominal or intracranial hemorrhage in later life.

Animals↗

Screening for inherited thrombotic disorders.

In order to determine a scheme for the screening of inherited thrombotic disorders, abnormalities considered as predisposing to thrombosis have been reviewed. Owing to the low prevalence of biological alterations, a selection of patients is required: documented venous thromboses, possibly at unusual sites (mesenteric vein, portal, cerebral veins), occurring before the age of 40 in patients with a positive family history of thromboses are relatively frequently associated with coagulation abnormalities. In addition, patients with skin necrosis at the initiation of oral anticoagulants, or with repeated superficial vein thrombosis or unexplained arterial occlusions at a young age might be included for screening. Tests have also to be selected. Some abnormalities, such as congenital deficiencies in antithrombin III, protein C and protein S, are recognized risk factors and have to be searched. Some others cannot be at present considered as definite risk factors (e.g., dysfibrinogenemias or deficiencies in factor XII), but their detection is easy by routine tests: prothrombin time, fibrinogen assay. Other abnormalities are recognized risk factors (or not) and need specific uncommon tests (e.g., study of fibrinolysis). Each time a biological abnormality is found, it is important to verify it is isolated since combined deficiencies have been observed and we should be able to answer the question whether the abnormality is the cause or the consequence of thrombosis, or a coincidence. Finally, in our experience, even in well selected patients, a coagulation disorder is detected in less than 30% of patients, so that new tests are needed to improve our knowledge in this field.

Antithrombin III Deficiency↗

Successful treatment of acquired factor VIII deficiency in a child using activated factor VII concentrates: case report and review of the literature.

Acquired factor VIII deficiency is a rare life-threatening disorder that should be suspected in individuals without a prior bleeding history who present with mucous membrane, muscle, and/or urinary tract bleeding. The authors describe a 5-year-old girl with epistaxis, intramuscular bleeding, and forearm compartment syndrome requiring emergent fasciotomy. Coagulation studies showed a factor VIII level of less than 1%. The prolonged activated partial thromboplastin time corrected immediately when mixed with normal plasma at a 1:1 ratio but became prolonged again following incubation at 37 degrees C. She was treated successfully with serial administrations of activated factor VII concentrates and immunosuppression with corticosteroids. Activated factor VII concentrates should be considered as an option for patients of all ages with acquired factor VIII deficiency.

Adrenal Cortex Hormones↗

Prothrombin time sensitivity and specificity to mild clotting factor deficiencies of the extrinsic pathway: evaluation of eight commercial thromboplastins.

Prothrombin-time (PT) sensitivity and specificity to mild clotting factor II, V, VII and X deficiencies have rarely been studied. We therefore carried out a prospective study, in 350 patients, of eight commercial thromboplastins (CTs) in their ability to detect mild clotting factor deficiencies, notably in factor VII. In each patient the factor II, V, VII and X clotting activities and PT performed with each CT were determined. For each CT, PT sensitivity and specificity in detecting factor deficiencies below 0.5 U/ml or below 0.4 U/ml were determined at various PTs, and then Receiver Operator Characteristic curves constructed. At optimum PT threshold level (sensitivity = specificity), exactitude varied from 0.64 to 0.74 (p < 0.01) and from 0.67 to 0.81 (p < 0.0001) in detecting deficiencies below 0.5 and 0.4 U/ml respectively. In conclusion, this study shows the limits of the PT test as performed with 8 CTs in patients with mild clotting factor deficiencies. The impact of such differences in sensitivity and specificity on monitoring certain patients subjects to decrease in coagulation factor, and, in particular, of those under low dose oral anticoagulant, remains to be determined.

Blood Coagulation Disorders↗

Factor VII activity and antigen in haemophilia B variants.

Twenty three patients belonging to 18 different pedigrees of Haemophilia B were studied with regard to ox-brain prothrombin time and its correlation to factor VII. Eleven among them were B-negative (no detectable factor IX antigen), five were B-reduced (factor IX antigen detectable but below the normal values) and seven were B-positive (normal levels of factor IX antigen). Ox-brain prothrombin time was found prolonged (greater than or equal to mean + 2.5 SD:99% confidence limits) in nine patients. Factor VII Activity (VII:C) was found reduced in 1/11 B-negative, in 2/5 B-reduced and in 4/7 B-positive patients. Factor VII Antigen (VII:Ag) was found normal in all but one patient. The ratio VII:C/VII:Ag was abnormal in eight patients independently from the variant of Haemophilia B. The underlying defect which causes the prolongation of Ox-brain prothrombin time due to factor VII:C mild deficiency is heterogeneous. Age, a mild Vitamin K deficiency, the presence of an inhibitor of Factor VII activation and other unknown causes, may be responsible for this pattern.

Adult↗

Activation of Hageman factor (factor XII) by bismuth subgallate, a hemostatic agent.

Bismuth subgallate is an effective agent in preventing hemorrhage after adenotonsillectomy. The experiments described demonstrate that this may occur through the activation of Hageman factor by this agent. Bismuth subgallate shortened the clotting time of whole blood, an action localized to an effect on the early steps of the intrinsic pathway; bismuth subgallate did not accelerate the thrombin time or prothrombin time of normal plasma, but could be substituted for kaolin as an activator of coagulation in assays of the partial thromboplastin time. The action of bismuth subgallate was localized to an effect on Hageman factor. It did not induce coagulation of plasma samples deficient in any of the recognized factors participating in the intrinsic pathway of thrombin formation, but it shortened the clotting time of plasma deficient in factor VII, a component of the extrinsic pathway. Evidence was obtained that Hageman factor exposed to bismuth subgallate corrected the defect of Hageman factor-deficient plasma and acquired amidolytic properties in the absence of other clotting factors. These studies provide a rationale for the hemostatic properties of bismuth subgallate.

Adolescent↗

Plasminogen activators, plasminogen activator inhibitors and procoagulant analyzed in twenty human tumor cell lines.

We have analyzed the CM of 20 human tumor cell lines for the presence of PA, PA-I and PC. Most of the cell lines expressed PA activity as measured by a radioiodinated fibrin plate assay. The urinary type and tissue-type PA activities were specifically quantified by means of purified inhibitory antibodies. U-PA and/or t-PA antigen, as measured by radioimmunoassays, were detected in all but 4 of the CM and were generally 10 times more concentrated than PA activity, indicating the presence of specific PA-Is. Analysis of CM by electrophoresis followed by fibrin-agarose zymography demonstrated the presence not only of free but also of inhibitor-complexed PA. Affinity purification demonstrated that 8/20 cell lines expressed detectable PA-I activity. The PA-I1 and PA-I2 inhibitors were most frequently observed, while PN was recovered only from CM of the HT1080 fibrosarcoma cell line. PC activity, as measured by the plasma recalcification time method, was found in 9/20 CM. It was of the thromboplastin tissue factor type since most of its activity was lost when assayed with a Factor VII-deficient plasma.

Blood Coagulation Factors↗

Abnormal secretion and function of recombinant human factor VII as the result of modification to a calcium binding site caused by a 15-base pair insertion in the F7 gene.

A case of a novel mutation in the F7 gene that results in factor VII coagulant activity (VII:c) of less than 1% and VII antigen (VII:Ag) levels of 10% is presented. DNA analysis revealed a homozygous 15-base pair (bp) in-frame insertion-type mutation at nucleotide 10554. This insertion consisted of a duplication of residues leucine (L)213 to aspartic acid (D)217 (leucine, serine, glutamic acid, histidine, and aspartic acid), probably arising by slipped mispairing between 2 copies of a direct repeat (GCGAGCACGAC) separated by 4 bp. Molecular graphic analyses showed that the insertion is located at the surface of the catalytic domain in an exposed loop stabilized by extensive salt-bridge and hydrogen bond formation at which the calcium binding site is located. The mutation probably interferes with protein folding during VII biosynthesis and/or diminishes functional activity through the loss of calcium binding. In vitro expression studies demonstrated that the levels of VII:Ag in lysates of cells transfected with wild type VII (VIIWT) were equivalent to those with mutant type VII (VIIMT), but the level of secreted VIIMT was 5% to 10% that of VIIWT. Pulse chase studies demonstrated that VIIMT did not accumulate intracellularly, and studies with inhibitors of protein degradation showed that recombinant VIIMT was partially degraded in the pre-Golgi compartment. Accordingly, only small amounts of VIIMT with undetectable procoagulant activity were secreted into conditioned media. These results demonstrate that a combination of secretion and functional defects is the mechanism whereby this insertion causes VII deficiency.

Base Pair Mismatch↗

Factor XII deficiency acquired by orthotopic liver transplantation: case report and review of the literature.

Transmission of congenital clotting factor deficiencies after orthotopic liver transplantation is rare. There are published reports of liver donor-to-recipient transmission of protein C deficiency with dysfibrinogenemia, protein S, factor VII and factor XI deficiencies. We report a case of transmission of factor XII deficiency with liver transplantation in a patient with Budd-Chiari syndrome. There was a persistent elevation of the activated partial thromboplastin time (aPTT), but no evidence of bleeding while the patient was maintained on warfarin. The presence of a persistently abnormal aPTT may raise suspicion for the presence of a clotting factor deficiency; however, deficiencies of other clotting factors may not be readily apparent on routine blood tests performed in a donor. Being aware of the possibilities of transmission of these inherited deficiencies of coagulation factors will aid in their early detection and management in the transplant donor and recipient.

Diagnosis, Differential↗