thromboplastin and Factor-VII-Deficiency

Recombinant activated coagulation factor VII (rFVIIa) was developed for the treatment of patients with hemophilia who have developed inhibitors against the factor they are missing. Hemophilia is a serious bleeding disorder and patients with hemophilia develop repeated spontaneous CNS, joint and muscle bleeding. Any trauma, even mild events, may cause life-threatening bleeding, and without treatment, these patients have a life expectancy of about 16 years. Thus, hemophilia can be regarded as a model of severe bleeding, and an agent capable of inducing hemostasis in severe hemophilia independent of the hemophilia proteins (FVIII or FIX) may also be effective in patients without hemophilia who experience serious bleeds. The availability of rFVIIa stimulated research on the role of FVII and tissue factor (TF) in the hemostatic process. As a result, a picture partly different from the one suggested by previous models has emerged. These previous models basically neglected the role of cells and cell membranes. The importance of platelets and platelet membrane phospholipids in hemostasis has been demonstrated, and the new concept of the hemostatic process, focusing on cell surfaces, has been outlined.

Topics: Cerebral Hemorrhage; Clinical Trials as Topic; Dose-Response Relationship, Drug; Factor VII Deficiency; Factor VIIa; Hemophilia A; Hemophilia B; Hemostatics; Infusions, Intravenous; Recombinant Proteins; Thromboplastin

Topics: Amino Acid Sequence; Factor VII; Factor VII Deficiency; Genetic Variation; Humans; Molecular Sequence Data; Phenotype; Protein Processing, Post-Translational; Structure-Activity Relationship; Thromboplastin

Topics: Amino Acid Sequence; Base Sequence; Binding Sites; Factor VII; Factor VII Deficiency; Gene Expression Regulation; Genes; Humans; Liver; Models, Molecular; Molecular Sequence Data; Protein Conformation; Structure-Activity Relationship; Thromboplastin

Factor VII appears to be the key regulatory protein in the initiation of both the intrinsic and extrinsic systems of coagulation. The single chain, or zymogen form, of factor VII possesses enzymatic activity which makes it an ideal candidate for the initiation of coagulation following vascular injury. A number of interactions between the intrinsic and extrinsic systems of coagulation have been identified. It appears that factor VII is capable of directly activating factor IX and vice versa. The study of factor VII variants with associated thromboembolic complications may provide a number of answers regarding the initiation and regulation of the blood coagulation process.

Topics: Blood Coagulation; Blood Coagulation Tests; Cerebral Hemorrhage; Enzyme Activation; Factor IX; Factor VII; Factor VII Deficiency; Hemarthrosis; Hemophilia A; Humans; Lipoproteins; Liver Diseases; Neutralization Tests; Partial Thromboplastin Time; Radioimmunoassay; Thromboplastin; Thrombosis; Vitamin K Deficiency

Factor VII, a single-chain zymogen, has sufficient proteolytic activity to initiate blood coagulation. The reason that coagulation does not occur continuously is that the zymogen like its 2-chain derivative enzyme, factor VIIa, absolutely requires tissue factor. The latter, a lipid-dependent glycoprotein, is not normally present in the blood. Upon tissue injury, however, coagulation is initiated by the activation of factors IX and X. The relationship of these events to the possibility that hemophilia A and B are tissue factor-dependent diseases is discussed.

Topics: Blood Coagulation; Factor IX; Factor IXa; Factor VII; Factor VII Deficiency; Factor VIIa; Factor X; Factor Xa; Hemophilia A; Humans; Kinetics; Thromboplastin; Thrombosis

A brief review of the interactions of the intrinsic and extrinsic coagulation pathway is given. The complex of thromboplastin and factor VII may well be the most important trigger in both pathways.

Topics: Animals; Blood Coagulation; Cattle; Chemical Phenomena; Chemistry; Factor IX; Factor IXa; Factor VII; Factor VII Deficiency; Factor VIIa; Factor X; Factor Xa; Humans; Kinetics; Thromboplastin

This communication describes the different techniques that can be used to evaluate the activity state of factor VII in plasma samples. At the present time direct methods for quantitation of activated factor VII (factor alpha-VIIa) are not available. Combined methods are therefore used to measure the degree of factor VII activation. These methods can be summarized in the following way: a regular factor VII clotting assay measuring factor VII coagulant activity (factor VIIc) is carried out simultaneously with: (1) a factor VII antigen assay (factor VIIag): (2) a coupled amidolytic factor VII assay (factor VIIam), or (3) a factor VII clotting assay utilizing bovine tissue thromboplastin (VIIbt). The activity state of factor VII can then be calculated from either of the following ratios: f.VIIc/f.VIIag; f.VIIc/f.VIIam, or f.VIIbt/f.VIIc. A study of the potency of a 30-fold activated factor VII to activate factor X in the presence of phospholipids is also included. This experiment demonstrates that even a low factor VII concentration (0.01 U/ml in the coupled amidolytic assay and 0.30 U/ml in the factor VII clotting assay) causes a significant activation of factor X when incubated together in the presence of lipids and calcium ions. Activated factor VII may therefore possess potential thrombotic properties even in the absence of exposed tissue thromboplastin in the blood circulation.

Topics: Animals; Antigens; Blood Coagulation Tests; Blood Specimen Collection; Cattle; Chromogenic Compounds; Factor VII; Factor VII Deficiency; Factor VIIa; Factor X; Factor Xa; Humans; Radioimmunoassay; Thromboplastin

In congenital factor VII deficiency the clinical picture is related to the levels of factor VII coagulant activity; when factor VII:C levels are very low the bleeding episodes can occur frequently. The most frequent bleedings are menorrhagia and metrorrhagia in females and hemarthrosis in both sexes. There are 3 immunological variants of factor VII deficiency: VII-, VIIR and VII+. Conversely, the genetic variants are 2: one characterized by no discrepancy between VII:C and VII:Ag (found in the heterozygotes of VII- and VIIR variants) and the other, in which a discrepancy between VII:C and VII:Ag is found (heterozygotes from VII+ kindreds). In factor VII deficiency, most commonly the human and ox tissue factors show the highest sensitivity to the coagulation defect, whereas the one extracted from rabbits is definitely less sensitive; the definition of functional variants is based upon a different reactivity to homologous and/or heterologous tissue thromboplastins. In no case was a PIVKA-VII-like protein found and none of the factor VII defective molecules reacted to the generation of important kallikrein activity.

Topics: Animals; Antigens; Blood Coagulation Tests; Cattle; Chromosome Aberrations; Chromosome Disorders; Chromosomes, Human, 6-12 and X; Cross Reactions; Factor VII; Factor VII Deficiency; Female; Genetic Carrier Screening; Genetic Variation; Humans; Male; Rabbits; Thromboplastin

Topics: Aminocaproates; Blood Coagulation Disorders; Blood Coagulation Factors; Blood Coagulation Tests; Blood Transfusion; Factor V Deficiency; Factor VII Deficiency; Factor VIII; Fibrinogen; Freezing; Hemophilia A; Hemophilia B; Hemorrhage; Hemostasis; Humans; Hypoprothrombinemias; Plasma; Plasma Volume; Prothrombin; Prothrombin Time; Thromboplastin; Vitamin K

The congenital factor VII (FVII) deficiency with an estimated incidence of one per 300 000 is the most common rare congenital bleeding disorder. The heterogeneous clinical pictures, including asymptomatic to life-threatening manifestations, are seen in patients with FVII deficiency. A variety of gene variants throughout the FVII ( F7 ) gene have been reported so far. In this setting, very rare FVII Padua polymorphism provokes an interesting condition in which results of prothrombin time and FVII activity are different based on the thromboplastin sources used in these tests. The current study aimed to report the phenotype and genotyping of patients with Padua variant. During the workup of the laboratory for FVII deficiency for diagnosis of FVII Padua, all patients with FVII deficiency who had prolonged prothrombin time, normal activated partial thromboplastin time, and variable FVII activity results using different sources of thromboplastin were included. Demographic data and clinical findings were recorded. For the molecular study, the F7 gene sequencing was performed using the Sanger sequencing technique. Five patients with FVII Padua and a history of mild-to-moderate bleeding, including easy bruising, epistaxis, gingivorrhagia, and bleeding after surgical challenges (including dental extraction and tonsillectomy), were detected during the study. DNA sequencing revealed a heterozygote CGG to CAG (Arg364Gln) variant in exon 9 at nucleotide position 1091, consistent with the genetic variant of FVII Padua. Timely diagnosis of FVII Padua is vital to avoid unnecessary exposure of patients to replacement therapy.

Topics: Factor VII; Factor VII Deficiency; Humans; Iran; Thromboplastin

Tissue factor (TF) pathway inhibitor (TFPI) is a Kunitz-type anticoagulation protein that inhibits activated factor VII (FVIIa)/TF complex. Incidentally, many different F7 gene variants, including TFPI-binding exosite mutations, have been reported in patients with congenital FVII deficiency and clinical bleeding variabilities. Here, TFPI-binding exosites (R147 and K192) on FVII zymogen were selectively disrupted to understand their roles in the pathogenesis of bleeding phenotypes. Expression of recombinant FVII variants (R147A, K192A, and R147A/K192A) demonstrated markedly reduced secretion of FVII owing to intracellular retention in the endoplasmic reticulum, as demonstrated by upregulation of the unfolded protein response genes in all FVII variants. FVII variants showed a similar FVII activation pattern and FVIIa amidolytic activity than FVII wild-type (WT). In contrast to FVII activation, R147A and K192A showed a 90% reduction in FX activation relative to WT, whereas the R147A/K192A variant demonstrated a 99% decrease in FX activation. The clotting time was markedly prolonged with R147A and K192A than WT, and no FVII coagulant activity was detected in R147A/K192A. In addition, the thrombin generation assay revealed a significant prolongation of lag time in all FVII variants. Our study explains how mutations of TFPI-binding exosites of FVII can lead to bleeding phenotypes in individuals carrying these aberrancies.

Topics: Factor VII Deficiency; Factor VIIa; Hemorrhage; Humans; Mutation; Phenotype; Thromboplastin

Acquired and isolated deficiencies in FVII are exceptional. They have mainly been reported during states of severe sepsis by the presence of proteases destroying the factor or neoplastic pathologies by the presence of an inhibitor. Consequently, very few cases have been published.. We report two cases of isolated and acquired deficiency of factor VII due to the presence of inhibitors which were related to bacterial sepsis in the first patient and to squamous cell carcinoma in the second patient, diagnosed in the Hematology Laboratory of the CHU Ibn Rochd.. Factor VII deficiency is a rare and poorly described deficiency that can be acquired or constitutional. The search for anti-factor VII antibodies by diluted thromboplastin time should be requested depending on the clinical context.

Topics: Antibodies; Factor VII; Factor VII Deficiency; Humans; Sepsis; Thromboplastin

Factor VII deficiency is the most common of the rare coagulation deficiencies. A hemorrhagic syndrome may occur in patients with FVII deficiency below 20%, although no correlation exist between the plasma FVII activity level (FVII:C) and the bleeding risk. Therefore, the management of surgery in patients with FVII deficiency remains challenging. Laboratory monitoring of FVII:C level may be helpful but should be interpreted with caution, because the dosage of FVII:C level may vary depending on the origin of the thromboplastin used. Herein, we report the case of the management of a woman who had been fortuitously diagnosed during pregnancy with FVII deficiency due to FVII variant Padua, which have induced discrepant results between two different laboratories.

Topics: Adult; Amino Acid Substitution; Blood Coagulation; Blood Coagulation Tests; Factor VII; Factor VII Deficiency; Female; Humans; Incidental Findings; Infant, Newborn; Mutation, Missense; Pregnancy; Pregnancy Complications, Hematologic; Thromboplastin

The performance of factor VII (FVII) assays currently used by clinical laboratories was examined in North American Specialized Coagulation Laboratory Association (NASCOLA) proficiency tests. Data from 12 surveys conducted between 2008 and 2010, involving 20 unique specimens plus four repeat-tested specimens, were analyzed. The number of laboratories per survey was 49-54 with a total of 1224 responses. Numerous reagent/instrument combinations were used. For FVII > 80 or <40 U/dL, 99.5% of results (859/863) were correctly classified by laboratories as normal/abnormal. Classification of specimens with 40-73 U/dL FVII was heterogeneous. Interlaboratory precision was better for normal specimens (coefficient of variation (CV) 10.7%) than for FVII<20 U/dL (CV 33.1%), with a mean CV of 17.2% per specimen. Intralaboratory precision for repeated specimens demonstrated no significant difference between the paired survey results (mean absolute difference 2.5-5.0 U/dL). For specimens with FVII >50 U/dL, among commonly used methods, one thromboplastin and one calibrator produced results 5-6 U/dL higher and another thromboplastin and calibrator produced results 5-6 U/dL lower than all other methods, and human thromboplastin differed from rabbit by +7.6 U/dL. Preliminary evidence suggests these differences could be due to the calibrator. For FVII <50 U/dL, differences among the commonly used reagents and calibrators were generally not significant.

Topics: Animals; Blood Coagulation Tests; Calibration; Canada; Factor VII; Factor VII Deficiency; Humans; Laboratories; Laboratory Proficiency Testing; Rabbits; Reference Values; Reproducibility of Results; Sensitivity and Specificity; Thromboplastin; United States

We report 2 asymptomatic homozygotes for the nonsense p.R462X mutation affecting the carboxy-terminus of coagulation factor VII (FVII, 466 aminoacids). FVII levels of 3-5% and 2.7 ± 0.4% were found in prothrombin time-based and activated factor X (FXa) generation assays with human thromboplastins. Noticeably, FVII antigen levels were barely detectable (0.7 ± 0.2%) which suggested a gain-of-function effect. This effect was more pronounced with bovine thromboplastin (4.8 ± 0.9%) and disappeared with rabbit thromboplastin (0.7 ± 0.2%). This suggests that the mutation influences tissue factor/FVII interactions. Whereas the recombinant rFVII-462X variant confirmed an increase in specific activity (~400%), a panel of nonsense (p.P466X, p.F465X, p.P464X, p.A463X) and missense (p.R462A, p.R462Q, p.R462W) mutations of the FVII carboxy-terminus resulted in reduced secretion but normal specific activity. These data provide evidence for counteracting pleiotropic effects of the p.R462X mutation, which explains the asymptomatic FVII deficiency, and contributes to our understanding of the role of the highly variable carboxy-terminus of coagulation serine proteases.

Topics: Animals; Blood Coagulation; Cattle; Child; Codon, Nonsense; Enzyme-Linked Immunosorbent Assay; Factor VII; Factor VII Deficiency; Female; Heterozygote; Homozygote; Humans; Male; Middle Aged; Mutagenesis, Site-Directed; Prothrombin Time; Rabbits; Thromboplastin

Congenital factor VII (FVII) deficiency is a bleeding disorder that requires optimal hemostatic management for each case due to its wide variety of bleeding symptoms. We experienced a patient with inherited FVII deficiency who demonstrated different FVII activities depending on tissue thromboplastins used for assays. An 82-year-old woman without any episodes of abnormal bleeding was found to have different FVII activities of 1.4% and 32% when assayed using thromboplastins from rabbit brain and human placenta, respectively. DNA sequencing analysis revealed a homozygous missense mutation of G10828A (FVII Padua) that caused an amino acid substitution of Arg304 to Gln (R304Q). Carriers of 304Q alleles are usually clinically asymptomatic and do not require FVII replacement therapies even in cases of homozygotes. In case a prolonged prothrombin time or reduced FVII activity is detected, re-examination using thromboplastins of other sources can be helpful for preliminary diagnosis of R304Q, in order to prevent unnecessary FVII replacement therapies.

Topics: Aged, 80 and over; Amino Acid Substitution; Animals; Factor VII; Factor VII Deficiency; Female; Homozygote; Humans; Mutation, Missense; Rabbits; Thromboplastin

The reagents most frequently used for FVII activity assay are obtained by rabbit brain or human placenta. In recent years, human recombinant thromboplastins have received great attention. FVII activity in FVII deficiency is usually low, regardless of the thromboplastin used. There are a few exceptions to this rule. These are represented by FVII Padua (Arg304Gln), FVII Nagoya (Arg304Trp), and FVII (Arg79Gln). In these three instances, clear discrepancies were noted in the FVII activity depending on the thromboplastin used. This indicates that at least two areas of FVII are involved in tissue binding, namely an epidermal growth factor domain of the light chain (Arg79Gln) and the catalytic domain (Arg304), controlled by exons 4 and 8, respectively. Since these three variants are cross reactive material positive, namely they are Type 2 defects, all other variants with normal antigen should be investigated by a panel of at least three tissue thromboplastins (rabbit brain, human tissue or human recombinant, and ox brain derived) in order to obtain a satisfactory classification.

Topics: Animals; Factor VII; Factor VII Deficiency; Homozygote; Humans; Rabbits; Thromboplastin; Treatment Outcome

Patients with the Arg304Gln mutation in factor VII Padua (FVII Padua) show discrepant activity levels that depend on the thromboplastin used in the assay system. This report investigates the possibility that residues close to Arg304 (exon 8) show the same discrepant behavior. All available homozygous patients with a mutation in a 13-residue region (preceding and following Arg304) have been evaluated. Only the Arg304Trp mutation showed a discrepancy similar to that shown by the Arg304Gln mutation. Other homozygotes failed to show differences, despite their all being positive for cross-reacting material. Another FVII amino acid residue involved in tissue factor binding and activation is Arg79 (exon 4). No comparison could be carried out because no homozygotes for deficiency in this region have ever been described. The relationship between these 2 residues involved in tissue factor binding and activation has not yet been completely clarified; however, Arg residues 79 and 304 are the only 2 residues definitely shown thus far to be involved in this important function.

Topics: Adolescent; Adult; Amino Acid Sequence; Amino Acid Substitution; Animals; Arginine; Catalytic Domain; Cattle; Exons; Factor VII; Factor VII Deficiency; Female; Genotype; Heterozygote; Homozygote; Humans; Male; Middle Aged; Mutation; Phenotype; Rabbits; Thromboplastin

Carbon monoxide derived from carbon monoxide releasing molecules (CORMs) has been demonstrated to enhance normal plasma thrombus speed of growth and strength in vitro. We tested the hypothesis that tricarbonyldichlororuthenium (II) dimer (CORM-2) improves the velocity of formation and strength of hemophiliac plasma thrombi as determined by thrombelastography. Plasma deficient (<1% normal activity) in factor VIII (FVIII; n = 11 individuals), factor IX (FIX; n = 5 individuals) or factor VII (FVII; n = 4 individuals) was exposed to 0 or 100 micromol CORM-2, with coagulation initiated with tissue factor. Coagulation kinetics were monitored with thrombelastography for 15 min. Paired t-tests were used to analyze FVIII-deficient plasma results; relative change was used to describe the other plasma types tested. In FVIII-deficient plasma, CORM-2 exposure significantly (P < 0.05) increased the velocity of thrombus formation (84%) and strength (48%) compared with plasma not exposed to CORM-2. FXI-deficient clots demonstrated an increase in velocity of formation (63%) and strength (43%) after CORM-2 exposure. Lastly, CORM-2 exposure increased FVII-deficient plasma velocity of formation (45%) and strength (63%). CORM-2 markedly enhanced the velocity of clot growth and strength in hemophiliac plasma. These findings serve as the rationale to determine whether CORMs could be utilized as hemostatic agents.

Topics: Blood Coagulation; Carbon Monoxide; Drug Evaluation, Preclinical; Factor VII Deficiency; Hemophilia A; Hemophilia B; Hemostatics; Humans; In Vitro Techniques; Organometallic Compounds; Plasma; Prodrugs; Thrombelastography; Thromboplastin

Topics: Adult; Animals; Factor VII; Factor VII Deficiency; Female; Humans; Male; Middle Aged; Rabbits; Thromboplastin

We investigated the frequencies of coagulation factor deficiencies in a Japanese population. We measured factor II, V, VII and X activity in 100 healthy individuals. A specific factor deficiency was determined according to the factor activity and the ratio of the factor activity to that of other coagulation factors. Seven samples showed factor activity less than the mean -2SD of standardized factor activity (factor II: three; factor V: one; factor VII: one; factor X: one and factor V+factor VII: one). The samples with low factor II and factor VII activity were determined not to be due to deficiency because the ratios of these factor activities to other factor activities were within the range of the mean +/- 2SD. We measured activity ratios in the remaining 97 samples and identified one sample with factor V deficiency and two with factor VII deficiency. Thus, six samples with coagulation factor deficiency were identified (factor X: one; factor V: two; factor VII: two and factor V + factor VII: one). These results suggest that the Japanese population has relatively high frequencies of mild factor V, factor VII and factor X deficiencies, in which activity is reduced to approximately 50% (36-64%) of normal plasma.

Topics: Adult; Animals; Factor V Deficiency; Factor VII Deficiency; Factor X Deficiency; Female; Gene Frequency; Humans; Indicators and Reagents; Japan; Male; Middle Aged; Prevalence; Prothrombin; Prothrombin Time; Rabbits; Species Specificity; Thromboplastin

Topics: Child; Disease Management; Factor VII Deficiency; Family Health; Female; Humans; Indicators and Reagents; Pedigree; Thromboplastin

The clinical phenotype manifest by patients with factor VII (FVII) deficiency correlates poorly with that predicted by laboratory tests. Despite its importance, there are no data on the variability of inter-laboratory determinations of low to very low plasma FVII activity (FVII:C).. We distributed three FVII-deficient plasma samples, prepared by immunoaffinity chromatography, to 58 laboratories in Japan. All samples were assayed using standardized reference plasma as a calibrator. Recombinant thromboplastin was also supplied as a common reagent.. In the case of sample A, which had a very low FVII:C, the use of standardized reference plasma and thromboplastin, lowered the variability of inter-laboratory measurements, when compared with the variability observed when samples were assayed using the respective laboratory's routine method.. The data obtained indicated that results for samples with a very low FVII:C were greatly influenced by the number of plasma dilutions used in constructing a standard activity curve, and also by the type of calibrator and thromboplastin. Such variability was not seen for samples with moderate FVII:C. We conclude that it is necessary to develop a more sensitive and accurate FVII:C measurement system for the diagnosis and treatment of FVII deficiency.

Topics: Calibration; Chemistry, Clinical; Chromatography, Affinity; Clinical Laboratory Techniques; Factor VII; Factor VII Deficiency; Humans; Japan; Laboratories; Reproducibility of Results; Sensitivity and Specificity; Thromboplastin

Topics: Adolescent; Binding Sites; Blood Coagulation; DNA Mutational Analysis; Factor VII; Factor VII Deficiency; Female; Genetic Predisposition to Disease; Heterozygote; Humans; Mutation, Missense; Pedigree; Phenotype; Point Mutation; Protein Conformation; Severity of Illness Index; Thromboplastin

Two assays [coagulant activity of factor VII (FVII:C) and activated factor VII (FVIIa) activity] are currently available for the assessment of factor VII and FVIIa pharmacokinetics. This article presents the results of a comparison of the two assays when applied both in vitro as well as during clinical pharmacokinetic trials of recombinant FVIIa (rFVIIa) administered to healthy individuals and haemophilia patients. The in-vitro data showed that, for the FVII:C assay, plasma samples do not dilute in parallel. For the FVIIa activity assay, dilutions of samples are both parallel and linear with different dilutions of the calibrator. Moreover, intra-assay variation was found to be smaller for the FVIIa activity assay than for the FVII:C assay. When adding different amounts of rFVIIa (0-6 microg/ml) to normal plasma, a mean specific activity of rFVIIa of 48.6 U/mug was observed on applying the FVII:C assay; however, the specific activity decreased with increasing levels of rFVIIa. For the FVIIa activity assay, the mean specific activity was 45.4 IU/mug. Direct comparison of the two activity assays showed that no simple conversion between FVII:C and FVIIa activity measurements are possible. When applying the two assays for pharmacokinetic assessments in two clinical trials, statistically significant different estimates for the area under the curve, half-life, clearance and volume of distribution were obtained. In conclusion, for evaluation of rFVIIa pharmacokinetic properties, activity should be measured with the FVIIa activity assay - which is a more specific and reliable assay of the two available factor VII activity assays, especially when assessing low activity levels.

Topics: Adolescent; Adult; Blood Coagulation; Blood Coagulation Tests; Child; Child, Preschool; Coagulants; Factor VII; Factor VII Deficiency; Factor VIIa; Hemophilia A; Humans; Male; Middle Aged; Plasma; Recombinant Proteins; Reference Values; Thromboplastin

To investigate the mechanism of clinical haemorrhage in an inherited coagulation factor VII (FVII) deficiency and tissue factor abnormality pedigree.. All exons, exon-intron boundaries and the 3', 5' untranslated sequences of FVII and tissue factor (TF) genes were amplified by PCR and sequenced directly. Any mutation identified by direct sequencing was confirmed by reverse sequencing. FVII cDNA of the proband was synthesized with random primers and amplified by nest PCR.. 55C-->T heterozygous mutation located in promoter of FVII gene was identified in the proband. The heterozygous mutation was derived from his mother. Tracing the other pedigree members found that his sister had the same heterozygous mutation and the others had wild-type FVII genes. A 9363 C-->T (Arg131Trp) heterozygous polymorphism in TF gene, which was 2.63% frequency of T allele polymorphism, was found in all of the pedigree members.. It was the first report that the -55C-->T heterozygous mutation in FVII gene and the Arg131Trp heterozygous polymorphism in TF gene explained the clinical symptom of the proband.

Topics: Adult; DNA Mutational Analysis; Factor VII; Factor VII Deficiency; Heterozygote; Humans; Male; Pedigree; Polymorphism, Genetic; Thromboplastin

Tissue factor pathway inhibitor (TFPI) is a 40-kDa, endogenous protein that inhibits tissue factor (TF)-initiated coagulation by bonding with activated factor X (FXa). The TFPI/FXa complex then subsequently binds with TF/activated factor VII (FVIIa) complex, ultimately inhibiting thrombin generation. Heparin administration causes endothelial release of TFPI concentrations up to sixfold normal values. Thrombelastography (TEG) is often used to monitor hemostasis in the perioperative period, and TFPI could potentially affect the diagnostic interpretation of TEG-based data, given its inhibition of both common and TF coagulation pathways. Thus, in this study we characterized the effect of TFPI on coagulation kinetics via TEG.. Whole blood, Factor VII-deficient plasma, and normal plasma were exposed in vitro to various concentrations of TFPI, after which unmodified, celite-activated, and TF-activated TEG were performed.. The addition of 87.5 ng/mL TFPI (twice normal concentration) was required to prolong clot propagation in whole blood, with propagation and strength only significantly affected by the addition of 175 ng/mL concentrations. Experiments with Factor VII-deficient plasma demonstrated that TFPI-mediated suppression of coagulation kinetics at these concentrations was secondary to FXa inhibition. Celite activation markedly attenuated TFPI-mediated effects on coagulation kinetics, whereas TF activation accentuated TFPI-mediated prolongation of clot initiation and diminution of propagation.. In settings involving heparin administration (e.g., cardiopulmonary bypass), TFPI-mediated inhibition of coagulation should be considered during TEG-based hemostatic monitoring.

Topics: Blood Coagulation; Diatomaceous Earth; Dose-Response Relationship, Drug; Factor VII Deficiency; Humans; Lipoproteins; Thrombelastography; Thromboplastin

Inherited factor (F)VII deficiency is rare in most populations but relatively common in Israel. The aim of this study was to characterize the molecular and functional defect in unrelated Israeli patients with FVII deficiency. Mutations were identified by direct sequencing of PCR-amplified genomic DNA fragments. Selected mutations were expressed in baby hamster kidney (BHK) cells and tested for binding to tissue factor (TF), activation by FXa and activation of FX. In 61 patients with FVII deficiency, the causative mutation in the FVII gene was discerned. The predominant mutation found in this and a previously reported cohort of 27 unrelated patients in Israel was Ala244Val substitution; of 121 independent mutant alleles defined in all 88 patients ascertained in Israel, 102 (84%) bore this alteration. Eleven additional mutations were identified of which one, Cys22Arg, is novel. Expression of the mutations in BHK cells revealed that four (Ala244Val, 11128delC, Leu300Pro and Cys22Arg) were cross-reacting material (CRM)- negative, and three (Ala294Val, Cys310Phe and Phe24del) were CRM-positive. As predicted by modeling, we observed no binding to TF of FVII Phe24del, diminished binding of FVII Cys310Phe and normal binding of FVII Ala294Val. The main defect of FVII Ala294Val was its inability to activate FX in the presence of TF. Coexpression of Ala294Val and Arg353Gln, a polymorphism known to affect FVII secretion, did not reveal an additive effect on FVII secretion, while coexpression of Ala244Val and Arg353Gln did yield an additive effect.

Topics: Cell Line; DNA Mutational Analysis; Factor VII; Factor VII Deficiency; Factor X; Factor Xa; Gene Frequency; Humans; Israel; Molecular Epidemiology; Mutation; Mutation, Missense; Protein Binding; Sequence Deletion; Thromboplastin; Transfection

We report the results of in vitro expression and biochemical characterization of the naturally occurring type II mutation Pro303Thr (P303T) in the factor VII (FVII) gene. Recombinant activated mutated FVII (FVIIa303T), compared with the activated wild-type FVII (FVIIaWT), showed reduced amidase activity toward synthetic substrates, especially when the observed reduced binding affinity for human soluble tissue factor (TF) (K(d) from 4.4 nmol/l for FVIIaWT to 17.3 nmol/l for FVIIa303T) was overcome by a fully saturating TF concentration. Likewise, factor X (FX) hydrolysis by FVIIa303T showed a reduced activity in the absence (and more severely in the presence) of TF (k(cat)/K(m) from 2.3 x 10(7)/mol/l s for FVIIaWT to 8.7 x 10(5)/mol/l s for FVIIa303T). These results showed that the mutant FVIIa is more shifted toward a zymogen-like form compared to FVIIaWT, suggesting that P303 facilitates the conformational transitions that stabilize the active form of FVIIa. The alteration of these allosteric equilibria is especially evident in the presence of TF, which was unable to shift the equilibrium toward a fully active FVIIa form. Additional experiments showed that both TF-catalysed FVII303T autoactivation and FVII303T activation by activated FX in the presence of TF were severely impaired, mainly because of an increase of the K(m) value. Altogether, these defects may explain the severe bleeding symptoms in a patient carrying the FVIIP303T mutation.

Topics: Adult; Blood Coagulation; Cell Line; Factor VII; Factor VII Deficiency; Factor VIIa; Factor Xa; Humans; Male; Point Mutation; Protein Conformation; Recombinant Proteins; Thromboplastin; Transfection

Factor VII (FVII) requires the cleavage of an internal peptide bond and the association with tissue factor (TF) to attain its fully active FVIIa conformation. This event alone leaves FVIIa in a zymogen-like state of relatively low specific activity. The TF-induced allosteric enhancement of FVIIa's activity contributes to the procoagulant activity of the complex. We have characterized two naturally occurring mutations (S363I - W364C) on FVII gene. Both homozygous patients for each mutation have a normal FVII: Ag level associated to an undetectable FVII coagulant activity. The patient carrying the allele 364C had a more severe hemorrhagic diathesis than the S363I mutant. To understand the mechanism of these deficiency, in vitro expression analysis with further biochemical characterization of recombinant proteins of both mutants FVII-363I, FVII-364C and wild type (WTFVII) FVII constructs were done. The results recapitulated the patients' plasma data with normal Ag level and no detectable coagulant activity. The D-F-Pip-R-pNA and CH(3)SO(2)-D-CHA-A-But-R chromogenic substrates were used to evaluate the amidolytic activity of WT and mutant FVII in presence and absence of recombinant tissue factor (rTF). Binding of FVII to rTF by a solid phase binding assay was done using recombinant human rTF. The results of amidolytic assays showed that rTF enhances 28 fold the value of the specificity of constant (kcat/K(m)) in WT but no activity was detectable in either mutant constructs under any condition. The equilibrium dissociation constant of rTF-FVIIa interaction showed Kd equal to 4.4 +/- 0.2nM, 4.9 +/- 0.5nM and 6 +/- 0.9 of WT, 363I and 364C FVII forms, respectively. The K(d) values of the non activated forms were equal to 24.7 +/- 3.3, 24.4 +/- 3.1 and 20.6 +/- 4nM, respectively. These data demonstrate that, compared to the WT form, FVII-363I and FVII-364C have no significant affinity change for TF and that the detrimental effect of these two mutations is attributable to the loss of an efficient catalytic machinery in the FVII molecule causing a severe deficiency of coagulant activities.

Topics: Adult; Catalysis; Chromogenic Compounds; Factor VII; Factor VII Deficiency; Factor X; Hemorrhagic Disorders; Homozygote; Humans; Kinetics; Male; Point Mutation; Protein Binding; Thromboplastin

The relationship between coagulation cascade activation and glioma cell proliferation was examined. The human glioma cell lines T98G, TM-1 and normal human astrocyte cell strain (NHA) were examined. Using anti-tissue factor (TF) antibody, immunocytochemical detection of TF antigen was obtained in both cell lines and cell strain. TF antigen in cell lysates was also measured by enzyme linked immunosorbent assay (ELISA). In a one-stage clotting assay, T98G, TM-1 and NHA revealed procoagulant activity (PCA) in normal human plasma and factor VII deficient plasma. PCA in normal human plasma was significantly inhibited by both inhibitory anti-TF antibody and cysteine protease inhibitor HgCl2. This result indicates that T98G, TM-1 and NHA cells express not only TF but also cancer procoagulant (CP) at the same time. In a cell proliferation assay, thrombin induced proliferation in T98G and TM-1 cells in a dose-dependent fashion and in NHA cell in a bell-shaped fashion. This mitogenic stimulant was inhibited by the specific thrombin inhibitor hirudin. The combinations of coagulation factors II, V, and X with or without factor VII induced proliferation in T98G, TM-1, and NHA cells. The maximal mitogenic stimulatory effects were larger in glioma cells than in NHA. These mitogenic stimulatory effects were also inhibited by hirudin. Each coagulation factor on its own or in any other combination of coagulation factors had no proliferative effect. Thus, these mitogenic stimulatory effects were considered to be the effect of thrombin. In conclusion, T98G and TM-1 human glioma cells express two different types of procoagulants TF and CP. In the presence of coagulation factors, these glioma cells can generate thrombin and this thrombin generation is capable of inducing glioma cell proliferation in vitro.

Topics: Antibodies; Blood Physiological Phenomena; Cell Division; Cysteine Endopeptidases; Cysteine Proteinase Inhibitors; Enzyme-Linked Immunosorbent Assay; Factor VII Deficiency; Glioma; Humans; Immunohistochemistry; Magnesium Chloride; Microscopy, Confocal; Neoplasm Proteins; Reference Values; Thrombin; Thromboplastin; Tumor Cells, Cultured

Factor VII (FVII) is a four-domain glycoprotein that plays a critical role in the initiation of blood coagulation. Hereditary deficiencies of this plasma protein results in a bleeding diathesis that varies in severity amongst affected patients. We have analysed the FVII gene in 27 patients with FVII deficiency from 21 unrelated families predominantly of Middle-Eastern extraction. A total of 19 different mutations were identified, of which 12 were novel and 7 had been previously reported. Nine of the 12 novel mutations were missense mutations located in the Gla domain (Ser23Pro), the second epidermal growth factor domain (Cys135Arg) and the catalytic serine protease domain (Arg247Cys, Arg277Cys, Ser282Arg, Pro303Thr, Ser363Ile, Trp364Cys, Trp364Phe), of which five are homozygous. Three novel splice mutations were identified in intron 1a (IVS1a+5), intron 2 (IVS2+1) and intron 6 (IVS6+1). Of the seven previously reported mutations, five were missense mutations of which three are homozygous (Gln100Arg, Arg152Gln, Arg304Gln, Cys310Phe and Thr359Met), one was a 17 bp deletion (10585del117bp) and one was a splice site mutation within intron 7 (IVS7+7). This study has significantly extended the current database of FVII mutations, including the number of known homozygous mutations. Conformational analyses of crystal structures for FVIIa and the FVIIa-tissue factor complex provided likely explanations for the effect of the missense mutations on FVIIa secretion or function. In particular, since 23 missense mutations were located to the serine protease domain, mostly to the region between the catalytic triad and the contact surface with tissue factor, this showed that the orientation of the serine protease domain relative to bound tissue factor in the complex is crucial for functional activity.

Topics: Adolescent; Adult; Amino Acid Sequence; Binding Sites; Child; Child, Preschool; DNA Mutational Analysis; Factor VII; Factor VII Deficiency; Family Health; Female; Hemorrhage; Hemostatics; Humans; Male; Middle Aged; Models, Molecular; Molecular Sequence Data; Mutation; Pedigree; Phenotype; Protein Structure, Tertiary; Serine Endopeptidases; Thromboplastin

We have previously described a kindred with factor VII (FVII) deficiency whose members exhibited reduced procoagulant activity relative to FVII antigen concentration. In this report, the molecular genetic basis of the FVII defect has been determined to be a heterozygous substitution of Asp for Asn at position 57 in the first epidermal growth factor (EGF) domain. Recombinant FVII (N57D) cDNA was created by site-directed mutagenesis and transiently expressed in human 293 cells. The transfected cells synthesized an immunoprecipitable protein with an apparent molecular weight of 50 kD. Quantitation of expression by FVII enzyme-linked immunosorbent assay indicated that mutant protein yields were consistently low, typically 10% to 30% of wild-type FVII. FVII (N57D) protein did not accumulate intracellularly, and Northern blot analysis indicated equivalent FVII mRNA levels in 293 cells expressing either wild-type FVII or FVII (N57D). Secreted FVII (N57D) protein did not bind tissue factor, exhibited no procoagulant activity, and failed to bind a conformation-dependent monoclonal antibody specific for the first EGF domain of FVII. Molecular modeling of the first EGF domain of FVII predicted that the N57D amino acid substitution would disrupt tertiary bonding structure. We conclude that the N57D mutation affects folding of the first EGF domain of FVII resulting in decreased cellular secretion of a mutant FVII molecule, which is unable to bind tissue factor and is therefore biologically inactive.

Topics: Animals; Antibodies, Monoclonal; Cell Line, Transformed; Cells, Cultured; COS Cells; DNA, Complementary; Factor VII; Factor VII Deficiency; Humans; Hydrogen Bonding; Models, Molecular; Mutagenesis, Site-Directed; Point Mutation; Protein Folding; Protein Structure, Tertiary; Recombinant Fusion Proteins; RNA, Messenger; Thromboplastin; Transfection

We have used recombinant mammalian expression and purification of the factor VII (FVII) variant Gln100 --> Arg (Q100RFVII) to study FVII deficiency in subjects with this mutation. Q100RFVII was secreted poorly in comparison with wild-type FVII (WTFVII) in a stable mammalian expression system, and purified variant protein was found to have undetectable clotting activity. Following activation by immobilized factor Xa, Q100RFVIIa had amidolytic activity similar to WTFVIIa in the absence of soluble tissue factor (sTF); however, unlike WTFVIIa no typical increase in activity was seen after addition of sTF. In a factor X activation assay using relipidated transmembrane truncated tissue factor (residues 1-243), Q100RFVIIa showed less than 5% of the ability of WTFVIIa to activate factor X. We performed direct binding analysis of WT and Q100RFVII/FVIIa to immobilized sTF using surface plasmon resonance, and severely reduced binding of both non-activated and activated Q100RFVII to sTF was seen, indicating a pronounced defect in tissue factor (TF) interaction with this variant. In the sTF-FVIIa crystal structure the candidate residue Gln100 is not in contact with TF but is at the epidermal growth factor 2-protease domain interface. We suggest that the mutation results in a global fold change severely reducing tissue factor interaction; mutation of FVII residues not directly involved in the interaction with TF may still result in variant FVII unable to take part in the initiation of coagulation.

Topics: Amino Acid Substitution; Animals; Arginine; Blood Coagulation; Factor VII; Factor VII Deficiency; Glycine; Humans; Mutation; Recombinant Proteins; Thromboplastin

A missense mutation at codon 100 in the second epidermal growth factor-like domain, resulting in Gln100-->Arg, was detected in 19 out of 21 available severely factor VII (FVII) deficient patients in Norway. Seventeen patients were homozygous, and the two remaining were compound heterozygotes. In the homozygous patients, FVII antigen was measured to 10-28%, and activity to 0.6-6.5% of that in normal pooled plasma. Recombinant FVII containing the mutation was expressed transiently in CHO cells to a mean antigen level of 57% of the wild type FVII protein, and with a specific activity of 6% of wild type. The mutant protein had a 14-fold reduction in affinity for tissue factor (TF), whereas binding of FX seemed unaffected. In line with the experimental data, molecular modelling of the mutation based on the coordinates of the tissue factor/FVIIa complex showed that substituting arginine for glutamine disrupts the interface between the catalytic and second epidermal growth factor-like domains.

Topics: Adolescent; Adult; Alleles; Amino Acid Sequence; Animals; Binding Sites; Blood Coagulation Tests; Child; Child, Preschool; CHO Cells; Codon; Cricetinae; DNA Mutational Analysis; Enzyme Activation; Factor VII; Factor VII Deficiency; Factor X; Female; Genotype; Glutamine; Humans; Male; Middle Aged; Models, Molecular; Molecular Sequence Data; Norway; Point Mutation; Protein Structure, Tertiary; Recombinant Proteins; Thromboplastin; Transfection

Topics: Animals; Antibodies, Monoclonal; Child; Enzyme-Linked Immunosorbent Assay; Epitopes; Factor VII; Factor VII Deficiency; Female; Humans; Point Mutation; Rabbits; Thromboplastin

I describe a method to measure blood coagulation properties, based on the hypothesis that the distance the serum component of a clotted plasma sample moves through a suitable absorbent material should be proportional to the blood's ability to clot. A simple apparatus was constructed to test this principle, in which an absorbent strip contacts clotted plasma samples. At various times, the liquid migration distance into the strip was measured and correlated with clotting times determined by well-accepted procedures. Use of this device to test lyophilized normal and barium-absorbed plasmas, factor VII-deficient plasma, frozen normal plasmas, plasmas from patients undergoing oral anticoagulation, and saline-diluted plasmas (as for Quick Percent assays) showed that clotting times correlated with migration distances for all types of samples (r2 = 0.93-0.99). The device distinguishes between samples from normal and coumadin-treated subjects. The concept can be integrated into an inexpensive, point-of-care coagulation monitor.

Topics: Absorption; Anticoagulants; Barium; Blood Coagulation; Blood Coagulation Tests; Drug Monitoring; Factor VII; Factor VII Deficiency; Freeze Drying; Hemostasis; Humans; Monitoring, Physiologic; Reference Values; Thromboplastin; Warfarin

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.

Topics: Blood Coagulation Disorders; Calibration; Case-Control Studies; Evaluation Studies as Topic; Factor VII Deficiency; Female; Humans; Linear Models; Male; Predictive Value of Tests; Prospective Studies; Prothrombin Time; Reference Values; Reproducibility of Results; Sensitivity and Specificity; Thromboplastin

We studied African-American Factor (FVII)-deficient variants and carriers in Georgia by measuring their levels of FVII antigen (FVIIAG) and FVII procoagulant (FVIIC). Factor VIIAG was determined using enzyme-linked immunoassay (ELISA), whereas FVIIC was measured in two ways: 1) by fibrin clotting methods that employed human recombinant (HRFVIIC), human placental (HPFVIIC), rabbit brain (RBFVIIC), and bovine brain (BBFVIIC) thromboplastins; and 2) by an amidolytic method (AMFVIIC). Prothrombin time tests (PT) were also performed by standard methods. These 4 FVII-deficient patients and 3 carriers demonstrated the following results: PT: 18.2 +/- 6.5 sec; FVIIAG: 73.0 +/- 14.9%; HRFVIIC: 30.6 +/- 20.3%; HPFVIIC: 30.5 +/- 21.4%; RBFVIIC: 25.3 +/- 21.4%; BBFVIIC: 30.6 +/- 17.5%; AMFVIIC: 44.1 +/- 18.3%. We conclude that a group of clinically mild African-American FVII-deficient variants exists in Georgia. This group is characterized by the presence of FVIIAG and decreased FVIIC, using a variety of thromboplastins; and excellent correlation was noted for both human thromboplastins.

Topics: Antibodies; Black People; Brain Chemistry; Enzyme-Linked Immunosorbent Assay; Factor VII; Factor VII Deficiency; Genetic Variation; Georgia; Humans; Partial Thromboplastin Time; Thromboplastin; United States

Plasma from healthy individuals, pregnant women and patients on warfarin were distributed to 3 laboratories supporting major cardiovascular surveys (Northwick Park, Muenster and Houston) for assay of factor VII coagulant activity (VIIc) with their own bio-assays. The mean VIIc in 147 samples agreed to within 1% of standard in Northwick Park and Houston, but was 14% of standard lower in Muenster owing to its more potent standard. In samples with an increased VIIc the Northwick Park assay gave a higher result than the other assays owing to its increased responsiveness to activated factor VII (VIIa). Thus when VIIa concentrations were determined directly with a clotting assay which utilises a soluble recombinant tissue factor, the increase in VIIc with increase in VIIa was considerably greater with the Northwick Park assay than the Muenster assay. This feature of the Northwick Park assay was traced to the virtual absence of protein C in its substrate plasma. Factor Va appears rate-limiting for the coagulant expression of VIIa in test plasma. If the thrombotic response to release of tissue factor is determined by the circulating concentration of VIIa, then the Northwick Park factor VII bio-assay may be preferable to other bio-assays currently employed to estimate risk of acute coronary events.

Topics: Adult; Blood Coagulation Tests; Coronary Disease; Enzyme Activation; Factor VII; Factor VII Deficiency; Female; Humans; Laboratories; Male; Pregnancy; Protein C; Protein S; Reproducibility of Results; Risk Factors; Sensitivity and Specificity; Thromboplastin; Warfarin

Factor VII (F.VII) is a vitamin-K-dependent serine protease required in the early stages of blood coagulation. We describe here a patient with severe F.VII deficiency, with a normal plasma F.VII antigen level (452 ng/mL) and F.VII activity less than 1%, who is homozygous for two defects: a G-->A transition at nucleotide 6055 in exon 4, which results in an Arg-->Gln change at amino acid 79 (R79Q); and a G-->A transition at nucleotide 8961 in exon 6, which results in an Arg-->Gln substitution at amino acid 152 (R152Q). The R79Q mutation occurs in the first epidermal growth factor (EGF)-like domain, which has previously been implicated in binding to tissue factor. The R152Q mutation occurs at a site (Arg 152-Ile 153) that is normally cleaved to generate activated F.VII (F.VIIa). Analysis of purified F.VII from patient plasma shows that the material cannot be activated by F.Xa and cofactors. In addition, in an in vitro binding assay using relipidated recombinant tissue factor, patient plasma showed markedly reduced binding to tissue factor at all concentrations tested. In an effort to separate the contributions of the two mutations, three recombinant variants, wild-type, R79Q, and R152Q, were prepared and analyzed. The R152Q variant had markedly reduced activity in a clotting assay, whereas R79Q showed a milder, concentration-dependent reduction. The R152Q variant exhibited nearly normal binding in the tissue factor binding assay, whereas the R79Q variant had markedly reduced binding. The time course of activation of the R79Q variant was slowed compared with wild-type. Our results suggest that the first EGF-like domain is required for binding to tissue factor and that the F.VII zymogen lacks activity and requires activation for expression of biologic activity.

Topics: Adult; Amino Acid Sequence; Base Sequence; Factor VII; Factor VII Deficiency; Humans; Male; Molecular Sequence Data; Mutation; Recombinant Proteins; Thromboplastin

We report a family with a combined factor VII Padua defect and von Willebrand's disease (vWd). The propositus is a 9-year-old child with a moderate bleeding tendency who appeared to be heterozygous for both factor VII Padua and type I vWd. The diagnosis of factor VII Padua was based on a normal factor VII antigen and factor VII activity which was low with rabbit brain thromboplastin but normal with ox brain thromboplastin. Type I vWd was diagnosed because of a concomitant decrease of von Willebrand factor antigen (vWf:Ag) and vWf ristocetin-cofactor activity (vWf:RCoF), associated with the presence of vWf multimers of all sizes in plasma and platelets. The parents were not consanguineous but came from the same isolated river Piave valley in North Eastern Italy where the factor VII Padua defect was first described. The father had the factor VII Padua defect but was clinically asymptomatic in accordance with the heterozygous state. The propositus's mother had type I vWd and was mildly symptomatic. The propositus' sisters, who were clinically asymptomatic, were both heterozygotes for factor VII Padua. The infusion of DDAVP normalized the factor VIII/vWf pattern in all patients. In the propositus, in contrast to the mother and normal subjects, showed a more rapid clearance both of vWf and factor VIII. The same pattern, albeit to a lesser degree, was also observed in the father.

Topics: Child; Deamino Arginine Vasopressin; Factor VII; Factor VII Deficiency; Female; Humans; Italy; Male; Pedigree; Thromboplastin; von Willebrand Diseases

Topics: Animals; Blood Coagulation Disorders; Brain Chemistry; Cattle; DNA Mutational Analysis; Factor VII; Factor VII Deficiency; Humans; Thromboplastin; von Willebrand Diseases

Topics: Animals; Factor VII; Factor VII Deficiency; Hemostasis; Humans; Rabbits; Thromboplastin

A more sensitive or higher concentration of rabbit brain thromboplastin does not result in greater accuracy and precision of results in oral anticoagulant therapy and is unable to mimic the PIVKA sensitivity of human brain. In terms of International Normalized Ratios the British Comparative Thromboplastin and Manchester Comparative Reagent (both now discontinued) and the Manchester Reagent had the poorest sensitivity to factor VII of all the reagents studied. It is not possible accurately to calibrate rabbit brain against human brain thromboplastin in the upper therapeutic range and beyond.

Topics: Animals; Brain Chemistry; Calibration; Factor V Deficiency; Factor VII Deficiency; Humans; Prothrombin Time; Rabbits; Reproducibility of Results; Thromboplastin; Ultrasonics; Whole Blood Coagulation Time

Disseminated intravascular coagulation invariably accompanies placement of peritoneovenous (LeVeen) shunts, which suggests that ascitic fluid contains procoagulant material capable of activating blood coagulation. In this study, we identified thrombogenic activity in human ascites and the hemostatic pathway by which it acts. Peritoneal fluid was removed percutaneously from patients with ascites due to various causes. Four fractions were prepared by centrifugation: cells, a low-speed, cell-free fluid, a high-speed supernatant, and the precipitate from the high-speed centrifugation. Cellular fractions from all ascitic fluids shortened a one-stage clotting time of normal pooled plasma by 68% in comparison with saline solution and endotoxin controls. Similarly, the cell-free fluids also shortened the clotting time of normal pooled plasma by 41%. The cellular and cell-free fractions shortened the clotting time of factor VIII-deficient plasma but failed to demonstrate procoagulant activity in factor VII-deficient plasma. These fractions had no effect on platelet aggregation or the platelet release reaction. The high-speed precipitate was dissociated by ethylenediaminetetra-acetate (EDTA) into fluid phase and precipitate, both of which demonstrated procoagulant activity. Furthermore, high-speed precipitate contained protein, phospholipid, and sterol in proportions similar to those of plasma membranes and contained membrane-bound vesicles as identified by means of electron microscopy. This material could be rendered inactive by heating to 100 degrees C for 2 minutes or by incubation with phospholipase C for 15 minutes. Finally, the ability of the high-speed precipitate to shorten the clotting time was prevented by preincubation with a monoclonal antibody, which is known to inhibit the procoagulant activity of human tissue factor. We suggest that several entities contribute to the procoagulant properties of human ascites, with procoagulant material deriving at least in part from peritoneal cells. The sedimentable procoagulant factor appears to be associated with cellular membranes or membrane fragments and is thromboplastin-like in its chemical composition, immunoreactivity, and substrate specificity.

Topics: Adult; Aged; Ascitic Fluid; Blood Coagulation Factors; Blood Coagulation Tests; Centrifugation; Factor VII Deficiency; Female; Hemophilia A; Humans; Leukocytes; Male; Microscopy, Electron; Middle Aged; Platelet Aggregation; Thromboplastin

Twenty-one asymptomatic individuals with a mildly prolonged prothrombin time (greater than 2 SD from the prothrombin time of the reference plasma) were found to have a mild isolated factor VII (F VII) defect (mean 38.8 U/dl; SD 13.2). Factor VII antigen levels were also found to be reduced (mean 45.5 U/dl; SD 7.8) in 13 of them. These figures were compared with those of 50 normals and 28 obligatory heterozygotes for F VII deficiency. The phenotypical behaviors in the propositi were found to be equal to those of the F VII congenital deficiency heterozygotes: the discrepant one (VII+) and the nondiscrepant one (VII-/R). Fifteen families of the propositi could also be studied, totalling 55 additional individuals; in 25 of them (ten pedigrees) a mild F VII deficiency was found showing the same phenotypical features of the corresponding propositi. We therefore believe that these individuals with mild F VII deficiency can be considered as heterozygotes for the defect, since the other vitamin K-dependent clotting factors were normal; the defect is transmitted throughout the kindred with the same mode of inheritance as F VII congenital deficiency; and F VII:C and F VII:Ag levels are highly comparable with those of known obligatory heterozygotes for F VII deficiency. On the grounds of a careful statistical analysis we propose a formula which allows a discrimination between the two phenotypes of the heterozygotes for F VII congenital deficiency. In addition it is suggested that sensitive tissue thromboplastins should be used to pick up these mild defects.

Topics: Adolescent; Adult; Antigens; Child; Child, Preschool; Factor VII; Factor VII Deficiency; Genetic Variation; Heterozygote; Humans; Middle Aged; Phenotype; Prothrombin Time; Thromboplastin

The functional activity of coagulation factors usually is determined using bioassays dependent on substrate plasmas deficient in the factor being measured. These are obtained most often from patients with hereditary deficiency and are frequently poorly characterized. The authors characterized seven commercially available hereditary Factor-VII-deficient substrate plasmas in terms of Factor VII activity and antigen level, and then compared them with a Factor-VII-deficient plasma prepared by immunoadsorption. All of the hereditary Factor-VII-deficient plasmas contained significant quantities of Factor VII antigen (120-217 ng/mL; normal, 250-600 ng/mL). One of the commercial substrate plasmas showed significant factor VII coagulant activity with a human thromboplastin. The sensitivity of the Factor VII assay system was dependent on both the source of Factor-VII-deficient plasma and the origin of the thromboplastins; human thromboplastin was more sensitive than rabbit thromboplastin, and immune-depleted plasma gave the most sensitive assay with each thromboplastin. These results indicate that immunoadsorbed plasma may be a superior reagent for coagulation factor assays.

Topics: Blood Coagulation Tests; Factor V; Factor VII; Factor VII Deficiency; Female; Fibrinogen; Humans; Immunosorbent Techniques; Pregnancy; Radioimmunoassay; Thromboplastin

Twenty-six patients with hereditary factor VII deficiency (VII:C less than 10%) were evaluated using a panel of three thromboplastins of varying species and tissue origin in both coagulant and chromogenic assay systems. Normal values for the coagulation and chromogenic assays were 104% +/- 7% and 108% +/- 21%, respectively. Factor VII antigen was measured by a specific radioimmunoassay (normal, 470 +/- 112 ng/mL). The patients were divided into two groups based on the factor VII:Ag assay results. Group 1, 18 patients, had decreased levels of factor VII:Ag and group 2, eight patients, had normal levels of factor VII:Ag. The two groups were further subdivided on the basis of discrepant factor VII:C levels in the chromogenic and coagulant assays. The number of observed patterns of functional factor VII:C activity suggests a high degree of complexity of factor VII and thromboplastin interaction. Whereas no clinical bleeding was reported in any of the nine black patients evaluated, all Caucasians (16) and one Hispanic presented with mild to severe bleeding. Patients with factor VII:C greater than 10% using a human thromboplastin had a negative bleeding history, regardless of the activity measured with other thromboplastins. Factor VII activity measured with a human thromboplastin appears to correlate best with the clinical picture.

Topics: Adolescent; Adult; Aged; Antigens; Black People; Blood Coagulation Tests; Child; Child, Preschool; Chromogenic Compounds; Factor VII; Factor VII Deficiency; Female; Humans; Immunochemistry; Male; Middle Aged; Radioimmunoassay; Thromboplastin; White People

Human isolated monocytes possess low levels of procoagulant activity, which was stimulated 10-30 fold by brief (2 hr) exposure to 10 micrograms/ml endotoxin. This activity was expressed in normal or factor XII-deficient plasma, but lost in plasma deficient in factors X or VII, indicating that it was due to thromboplastin. The stimulation of monocyte thromboplastin by endotoxin was inhibited in a dose-dependent manner by two phospholipase A2 inhibitors, 4-bromophenacyl bromide and quinacrine, and by two lipoxygenase inhibitors, eicosatetraynoic acid and nordihydroguaiaretic acid. Two cyclooxygenase inhibitors, aspirin and indomethacin, prevented endotoxin-induced increases in thromboxane B2 production but had no effect on thromboplastin production. These results suggest that a component in the sequence of lipid deacylation, arachidonic acid release, and metabolism via lipoxygenase may mediate the stimulation of monocyte thromboplastin activity by endotoxin.

Topics: Arachidonate Lipoxygenases; Arachidonic Acid; Arachidonic Acids; Cyclooxygenase Inhibitors; Endotoxins; Factor VII Deficiency; Factor X Deficiency; Humans; Lipoxygenase Inhibitors; Monocytes; Phospholipases A; Phospholipases A2; Thromboplastin; Thromboxane B2

Undisrupted cells of the human monocytic tumor cell line U937 have procoagulant activity that is Ca2+ dependent and is not demonstrable in Factor VII or Factor X deficient plasma. Furthermore, U937 cells when incubated with purified human Factor VII in the presence of Ca2+ and then repeatedly washed promoted coagulation of Factor VII deficient plasma in the absence of added tissue factor. Culture with endotoxin increased the procoagulant activity of U937 cells approximately 5-fold. In separate experiments, exposure to lymphokines obtained from phytohemagglutinin-stimulated lymphocytes enhanced the procoagulant activity of U937 cells 4 to 110-fold. Other cell lines (of myeloid and lymphoid origin) tested lacked the procoagulant activity found in U937 cells. These results indicate that the constitutive tissue factor-like activity of U937 cells resembles that of normal activated human monocytes.

Topics: Binding Sites; Blood Coagulation; Blood Coagulation Factors; Cell Line; Cell Transformation, Neoplastic; Endotoxins; Factor VII; Factor VII Deficiency; Factor X Deficiency; Factor XI Deficiency; Humans; Lymphokines; Lymphoma, Large B-Cell, Diffuse; Monocytes; Thromboplastin

A patient with a peculiar factor VII is described. The propositus is a 70-year-old man without any bleeding tendency. The coagulation pattern is characterized by a prolonged rabbit brain prothrombin time, a normal Stypven cephalin clotting time and a normal thrombotest. Factor VII activity is low when assayed using rabbit brain the thromboplastin but is normal when assayed using ox brain thromboplastin. The neutralization test performed with an antifactor VII antiserum revealed a normal factor VII antigen level. A pedigree study has not been possible, the patient having no living relatives. No differences were observed between the biological results of our patient and those described by Girolami as factor VII + Padua.

Topics: Aged; Animals; Blood Coagulation Tests; Cattle; Factor VII; Factor VII Deficiency; Humans; Male; Prothrombin Time; Rabbits; Thromboplastin

To study the interrelationships of the major human coagulation pathways, factor X activation in normal and various deficient human plasmas was evaluated when clotting was triggered by dilute rabbit or human thromboplastin. Various dilutions of thromboplastin were added to plasma samples containing 3H-labeled factor X, and the time course of factor X activation was determined. At a 1/250 dilution of rabbit brain thromboplastin the rate of factor X activation in factor VIII or factor IX deficient plasma was only 10% of the activation rate seen for normal or factor XI deficient plasma. Reconstitution of the deficient plasmas with factors VIII or IX, respectively, restored normal factor X activation. Similar results were obtained when various dilutions of human thromboplastin replaced the rabbit thromboplastin. From these experiments, it is inferred that normal activation of factor X in plasma due to dilute thromboplastin requires factors VII, IX and VIII. An alternative extrinsic pathway that involves factors VII, IX, and VIII may be a major physiologic extrinsic pathway, and this pathway may help to explain the clinical observations of bleeding diatheses in patients deficient in factors IX or VIII.

Topics: Animals; Blood Coagulation; Factor VII Deficiency; Factor X; Factor Xa; Factor XI Deficiency; Hemophilia A; Humans; Kinetics; Prothrombin Time; Rabbits; Thromboplastin

Spectrophotometric assays for the measurement of coagulation factor activities in plasma have been developed using a relatively specific chromogenic substrate for thrombin. The tissue-factor-activated assay system involves the activation of factors VII and X and prothrombin. The surface-activated assay system involves the activation of factors XII, PK, XI, IX, VII, X and prothrombin using factors V and VIII as cofactors. The thrombin generated subsequent to activation in these two assay systems is measured via its activity on the chromogenic substrate Sarc-Pro-Arg-pNA. These spectrophotometric assays provide a higher degree of sensitivity as compared with the clotting time assays. The tissue-factor-activated system provides a sensitive method for monitoring coumarin therapy. The surface-activated assay system can detect deficiencies of all the factors measured by the conventional APTT assay system, as well as factor VII. Furthermore, this assay provides a sensitive method for monitoring heparin therapy.

Topics: Animals; Blood Coagulation; Cattle; Chromogenic Compounds; Factor VII Deficiency; Heparin; Rabbits; Spectrophotometry; Thrombin; Thromboplastin

Intact arterial vessel wall is not thrombogenic. Disorders of the endothelium in connection with pathological coditions such such as atherosclerosis, hyperlipidaemia, hypertension and hyperuricemia induce interaction of surfaces of high thromboplastic activity with the blood stream. In such situations local formation of thrombin will take place immediately. Evidence is presented for the essential and unique activation of the extrinsic pathway of the plasmatic coagulation system. The local formation of thrombin at pathologically altered arterial wall seems to be an important trigger for arterial thrombosis and haemostasis. It could be that in vivo the initial step of thrombogenesis depends upon the formation of the activator complex between tissue-thromboplastin and factor VII.

Topics: Aged; Aorta, Abdominal; Arteries; Arteriosclerosis; Blood Coagulation; Factor VII Deficiency; Humans; Middle Aged; Partial Thromboplastin Time; Prothrombin Time; Reference Values; Thromboplastin

Topics: Animals; Dogs; Factor VII; Factor VII Deficiency; Factor X; Factor X Deficiency; Haplorhini; Humans; Macaca fascicularis; Male; Phenindione; Prothrombin Time; Rabbits; Rats; Species Specificity; Thromboplastin

Topics: Afibrinogenemia; Blood Coagulation Disorders; Blood Coagulation Tests; Factor V Deficiency; Factor VII Deficiency; Factor X Deficiency; Factor XI Deficiency; Factor XII Deficiency; Factor XIII Deficiency; Hemophilia A; Hemophilia B; Humans; Hypoprothrombinemias; Kaolin; Phosphatidylethanolamines; Prekallikrein; Prothrombin Time; Thrombin; Thromboplastin; von Willebrand Diseases

Factor VII can be activated, to a molecule giving shorter clotting times with tissue factor, by incubating plasma with kaolin or by clotting plasma. The mechanisms of activation differ. With kaolin, activated Factor XII (XII(a)) was the apparent principal activator. Thus, Factor VII was not activated in Factor XII-deficient plasma, was partially activated in prekallikrein and high-molecular weight kininogen (HMW kininogen)-deficient plasmas, but was activated in other deficient plasmas. After clotting, activated Factor IX (IX(a)) was the apparent principal activator. Thus, Factor VII was not activated in Factor XII-,HMW kininogen-, XI-, and IX-deficient plasmas, but was activated in Factor VIII-, X-, and V-deficient plasmas. In further studies, purified small-fragment Factor XII(a) (beta-XII(a)), kallikrein, and Factor IX(a) were added to partially purified Factor VII and to plasma. High concentrations of beta-XII(a) activated Factor VII in a purified system; much lower concentrations of beta-XII(a) activated Factor VII in normal plasma but not in prekallikrein or HWM kininogen-deficient plasmas. Kallikrein alone failed to activate partially purified Factor VII but did so when purified Factor IX was added. Kallikrein also activated Factor VII in normal, Factor XII-, and Factor IX-deficient plasmas. Purified Factor IX(a) activated partially purified Factor VII and had no additional indirect activating effect in the presence of plasma. These results demonstrate that both Factor XII(a) and Factor IX(a) directly activate human Factor VII, whereas kallikrein, through generation of Factor XII(a) and Factor IX(a), functions as an indirect activator of Factor VII.

Topics: Blood Coagulation; Factor IX; Factor VII; Factor VII Deficiency; Factor XII; Humans; Kallikreins; Thromboplastin

Topics: Administration, Oral; Animals; Anticoagulants; Biomarkers; Blood Coagulation Disorders; Blood Proteins; Cattle; Cold Temperature; Factor VII; Factor VII Deficiency; Factor X; Factor X Deficiency; Humans; Hypoprothrombinemias; Kaolin; Protein Precursors; Prothrombin; Prothrombin Time; Rabbits; Thromboplastin; Vitamin K

The coagulant of normal human saliva has been identified as tissue factor (thromboplastin, TF) by virtue of its ability to cause rapid coagulation in plasmas deficient in first-stage coagulation factors and to activate factor x in the presence of factor VII and by virtue of the fact that its activity is expressed only in the presence of factor VII and is inhibited by an antibody to TF. The TF is related to cells and cell fragments in saliva. Salivary TF activity has been found to be significantly reduced in patients taking warfarin. The decline in TF activity during induction of warfarin anticoagulation occurs during the warfarin-induced decline in vitamin-K-dependent clotting factor activity, as judged by the prothrombin time. The decrease in TF activity is not related to a reduction in salivary cell count or total protein content or to a direct effect of warfarin on the assay. It is hypothesized that the mechanism by which warfarin inhibits TF activity may be related to the mechanism by which it inhibits expression of the activity of the vitamin-K-dependent clotting factors. Inhibition of the TF activity may be involved in the antithrombotic effect of warfarin.

Topics: Factor VII; Factor VII Deficiency; Factor X; Factor XI Deficiency; Factor XII Deficiency; Freezing; Hemophilia A; Hemophilia B; Humans; Hyaluronoglucosaminidase; Prothrombin; Thromboplastin; Warfarin

One-stage prothrombin times of normal and of factor VII-deficient beagle plasma were determined with two types of beagle brain thromboplastin, one prepared from normal beagles and the other from factor VII-deficient beagles. There was little difference between the reagents in the prothrombin times obtained for normal plasma. However, when factor VII-deficient plasma was tested, reagent prepared from factor VII-deficient beagles gave considerably longer prothrombin times than were obtained with the normal reagent and the difference increased with increasing reagent concentration to a maximum at 140 mg/ml. Prothrombin times of a series of mixtures of normal and factor VII-deficient plasma indicated that the presence of only 1/90 part of normal plasma was necessary to compensate for the difference between the two reagents. Determination of the iron content of the reagent suggested that the microcirculation of an average brain contained some 1.8 g of whole blood. The finding that brain thromboplastin prepared from factor VII-deficient beagles is more sensitive to a deficiency of factor VII in plasma, presumably a result of the smaller quantity of factor VII present in the reagent, is compatible with the known kinetics of extrinsic coagulation.

Topics: Animals; Brain; Dogs; Factor VII Deficiency; Iron; Prothrombin Time; Thromboplastin

A few neonates born to mothers receiving anticonvulsant drugs during pregnancy have shown defects in vitamin K dependent clotting factors with or without clinical bleeding. Experimentally, phenytoin (diphenyl hydantoin, DPH) has induced clotting defects in cats and inhibited production of clotting factors in rat liver slices. Phenobarbital has produced similar but milder defects. Anticonvulsants have been observed to produce clotting defects in 9 children, 2 weeks to 8 years in age. Elevated levels of phenytoin or other anticonvulsants, or a combination of anticonvulsants were measured in the children. Six patients were on drug combination including two or more of the following: phenytoin, phenobarbital, primidone, carbamazepine, diazepam, ethosuximide. Clotting defects included: elevated prothrombin time, elevated partial thromboplastin time, diminished factors V, VII or X. All children had neurologic symptoms of anticonvulsant toxicity, but the only hematologic problems were oozing from venipuncture sites and increased bruising in 3. All patients were on normal diets and had normal liver function tests. By lowering the level of anticonvulsants, clotting factors returned toward normal. Elevated levels of anticonvulsants can potentially produce clotting defects in neonates and young children.

Topics: Anticonvulsants; Blood Coagulation; Blood Coagulation Disorders; Blood Coagulation Tests; Child; Child, Preschool; Factor V Deficiency; Factor VII Deficiency; Factor X Deficiency; Female; Hemophilia A; Humans; Infant; Infant, Newborn; Male; Maternal-Fetal Exchange; Pregnancy; Prothrombin Time; Thromboplastin

Topics: Blood Coagulation; Blood Coagulation Tests; Blood Preservation; Calcium Chloride; Dose-Response Relationship, Drug; Factor VII Deficiency; Factor X Deficiency; Glass; Humans; Hypoprothrombinemias; Oxalates; Prothrombin Time; Thromboplastin

Topics: Animals; Cattle; Dicumarol; Drug Contamination; Drug Stability; Factor VII Deficiency; Factor X Deficiency; Haplorhini; Humans; Indicators and Reagents; Plasma; Prothrombin Time; Quality Control; Rabbits; Thromboplastin

A large kindred with combined deficiencies of factors VII and IX is presented. The deficiencies appeared to be independent and the data were not consistent with a diagnosis of haemophilia BM. The identification of mildly affected family members, including carriers of haemophilia B and heterozygotes for factor-VII deficiency, was facilitated by comparison with the 95% confidence interval of an age- and sex-matched control population. The bleeding patterns were those of mild to moderate haemophilia B and did not appear to have been modified by the presence of factor-VII deficiency.

Topics: Factor IX; Factor VII; Factor VII Deficiency; Hemophilia B; Humans; Male; Middle Aged; Pedigree; Prothrombin; Thromboplastin

Topics: Adult; Afibrinogenemia; Animals; Blood Cell Count; Blood Coagulation; Blood Coagulation Tests; Blood Platelets; Cattle; Citrates; Collagen; Crystallization; Dogs; Edetic Acid; Factor VII Deficiency; Factor X Deficiency; Factor XII; Female; Fibrinogen; Hemophilia A; Hemostasis; Heparin; Humans; Male; Platelet Adhesiveness; Platelet Aggregation; Purpura, Thrombocytopenic; Thrombin; Thromboplastin; von Willebrand Diseases

Topics: Blood Coagulation Disorders; Blood Coagulation Tests; Factor VII Deficiency; Hemophilia A; Humans; Prothrombin Time; Thrombocytopenia; Thromboplastin; Vitamin K Deficiency

Topics: Blood Coagulation Tests; Coumarins; Factor VII Deficiency; Factor X Deficiency; Humans; Hypoprothrombinemias; Plasma; Thromboplastin; Vitamin K

Topics: Animals; Brain Chemistry; Cattle; Factor VII; Factor VII Deficiency; Humans; Isoflurophate; Thromboplastin; Tissue Extracts

Topics: Animals; Blood Coagulation Disorders; Cattle; Factor VII Deficiency; Factor X; Humans; Hypoprothrombinemias; Prothrombin; Rabbits; Swine; Thromboplastin; Warfarin

Topics: Blood Coagulation; Cerebral Hemorrhage; Factor VII; Factor VII Deficiency; Female; Heterozygote; Homozygote; Humans; Infant; Pedigree; Thromboplastin

Topics: Adenocarcinoma, Mucinous; Animals; Arginine; Blood Coagulation; Blood Coagulation Tests; Brain Chemistry; Bronchi; Chemical Precipitation; Disseminated Intravascular Coagulation; Esterases; Factor V Deficiency; Factor VII; Factor VII Deficiency; Factor X; Fibrinogen; Hemophilia B; Humans; Hypoprothrombinemias; Kaolin; Mucins; Mucus; Muramidase; Phospholipids; Prothrombin; Rabbits; Thromboplastin; Time Factors; Venoms

Topics: Adult; Blood Coagulation Tests; Factor IX; Factor VII; Factor VII Deficiency; Factor X; Female; Hemorrhagic Disorders; Heterozygote; Homozygote; Humans; Male; Prothrombin; Prothrombin Time; Thromboplastin

Topics: Adenosine Diphosphate; Afibrinogenemia; Anti-Inflammatory Agents; Aspirin; Blood Platelets; Citrates; Densitometry; Dose-Response Relationship, Drug; Drug Stability; Drug Storage; Epinephrine; Factor V Deficiency; Factor VII Deficiency; Factor XIII Deficiency; Fatty Acids, Nonesterified; Heparin; Humans; Platelet Adhesiveness; Serum Albumin; Temperature; Thromboplastin; Time Factors

Topics: Acid Phosphatase; Animals; Blood Coagulation Tests; Brain; Cells, Cultured; Centrifugation; Cytoplasmic Granules; Dogs; Factor V Deficiency; Factor VII Deficiency; Factor X; Factor XI Deficiency; Hemophilia B; In Vitro Techniques; Leukocytes; Micropore Filters; Peritoneal Cavity; Thromboplastin

Topics: Anticoagulants; Blood Coagulation; Blood Coagulation Disorders; Blood Coagulation Tests; Chemical Phenomena; Chemistry; Chromatography, DEAE-Cellulose; Factor V Deficiency; Factor VII Deficiency; Factor XII; Hemophilia A; Humans; Hypoprothrombinemias; Phospholipids; Prothrombin; Prothrombin Time; Thrombin; Thromboplastin

Topics: Animals; Blood Coagulation; Brain; Dog Diseases; Dogs; Factor VII Deficiency; Horses; Humans; Mammals; Plasma; Rabbits; Sheep; Swine; Thromboplastin; Time Factors; Tissue Extracts

Topics: Animals; Blood Coagulation Tests; Dog Diseases; Dogs; Enzymes; Factor VII Deficiency; Factor XIII; Pedigree; Prothrombin Time; Sulfobromophthalein; Thromboplastin; Venoms

Topics: Animals; Behavior, Animal; Blood Coagulation; Blood Coagulation Disorders; Blood Coagulation Tests; Brain; Cattle; Dog Diseases; Dogs; Factor VII Deficiency; Fish Diseases; Fresh Water; Humans; Immunization, Passive; Marine Biology; Plasma; Prothrombin Time; Reproduction; Salmon; Seawater; Species Specificity; Temperature; Thrombin; Thromboplastin; Tissue Extracts

Topics: Blood Coagulation; Blood Coagulation Factors; Blood Coagulation Tests; Blood Platelets; Endotoxins; Factor V Deficiency; Factor VII Deficiency; Factor VIII; Hemophilia B; Humans; Hypoprothrombinemias; Leukocyte Count; Leukocytes; Plasma; Serratia marcescens; Thromboplastin

Topics: Blood Platelets; Chromatography, DEAE-Cellulose; Factor IX; Factor VII; Factor VII Deficiency; Factor X; Hemophilia B; Humans; Methods; Neutralization Tests; Phenindione; Prothrombin; Prothrombin Time; Thromboplastin; Venoms

A severe, pure deficiency of factor VII has been defined in haematological and biochemical terms in the Alderley Park colony of beagle dogs. By modification of the conventional factor VII assay to improve its specificity an apparent low activity of between 1 and 2.5% of the normal beagle has been found. When this plasma is used as a substrate for factor VII assays it compares well with human factor VII-deficient plasma in the measurement of both raised and depressed factor VII activity. It also appears to be a valuable reagent in the quality control of tissue thromboplastin extracts.

Topics: Animals; Blood Coagulation Disorders; Blood Coagulation Tests; Chromatography, Gel; Dog Diseases; Dogs; Factor IX; Factor V; Factor VII; Factor VII Deficiency; Factor VIII; Factor X; Fibrinogen; Humans; Phosphatidylethanolamines; Prothrombin Time; Thrombelastography; Thrombin; Thromboplastin; Tissue Extracts

Topics: Adult; Blood Coagulation Tests; Factor VII; Factor VII Deficiency; Humans; Male; Prothrombin Time; Thromboplastin

Topics: Animals; Brain; Dicumarol; Dogs; Factor VII Deficiency; Humans; Hypoprothrombinemias; Indicators and Reagents; Phenols; Prothrombin Time; Rabbits; Thromboplastin; Tissue Extracts

Topics: Adult; Aged; Blood Coagulation Disorders; Blood Coagulation Tests; Diagnosis, Differential; Factor VII Deficiency; Factor X; Female; Genes, Recessive; Heterozygote; Humans; Hypoprothrombinemias; Immunodiffusion; Male; Middle Aged; Neutralization Tests; Prothrombin; Prothrombin Time; Thromboplastin

Topics: Analysis of Variance; Animals; Anticoagulants; Blood Coagulation Disorders; Blood Coagulation Factors; Blood Coagulation Tests; Brain; Cattle; Coumarins; Factor VII; Factor VII Deficiency; Factor X; Humans; Hypoprothrombinemias; Indicators and Reagents; Methods; Prothrombin Time; Rabbits; Thromboplastin; Warfarin

Topics: Blood Coagulation; Blood Coagulation Factors; Blood Coagulation Tests; Factor V Deficiency; Factor VII Deficiency; Factor XI Deficiency; Factor XIII; Hemophilia B; Hemostasis; Humans; Leishmaniasis, Visceral; Phospholipids; Prothrombin Time; Thrombocytopenia; Thromboplastin

Topics: Animals; Cattle; Dogs; Factor V; Factor VII; Factor VII Deficiency; Factor X; Fibrinogen; Humans; Male; Methods; Phosphatidylethanolamines; Plasma; Prothrombin; Prothrombin Time; Thromboplastin; Warfarin

Topics: Animals; Biological Assay; Blood Coagulation Disorders; Brain; Cattle; Coumarins; Factor VII Deficiency; Humans; Hypoprothrombinemias; In Vitro Techniques; Methods; Prothrombin Time; Rabbits; Thromboplastin

Topics: Animals; Blood Chemical Analysis; Brain; Dogs; Factor VII; Factor VII Deficiency; Humans; Liver Function Tests; Prothrombin Time; Thromboplastin

Topics: Animals; Cattle; Dicumarol; Dogs; Factor VII Deficiency; Factor XI Deficiency; Fibrin; Hemophilia A; Hemophilia B; In Vitro Techniques; Prothrombin; Snakes; Thrombin; Thromboplastin; Time Factors; Tissue Extracts; Venoms; Vitamin K

Topics: Blood Coagulation Tests; Factor IX; Factor VII Deficiency; Female; Humans; Infant; Prothrombin; Purpura; Thromboplastin; Vitamin K

Topics: Anticoagulants; Antithrombin III; Blood Coagulation; Blood Coagulation Disorders; Blood Platelets; Calcium; Chemical Phenomena; Chemistry; Drug Therapy; Enzyme Inhibitors; Factor VII Deficiency; Glucose; Glycine; Hemophilia A; Heparin; Humans; Hypoprothrombinemias; Mannitol; Phospholipids; Sucrose; Thiourea; Thrombin; Thromboplastin

Topics: Blood Coagulation Factors; Blood Coagulation Tests; Brain; Child; Factor VII; Factor VII Deficiency; Female; Humans; In Vitro Techniques; Thrombin; Thromboplastin; Tissue Extracts

Topics: Animals; Biochemical Phenomena; Biochemistry; Biological Assay; Blood Coagulation; Blood Coagulation Factors; Blood Coagulation Tests; Brain; Chromatography; Factor VII; Factor VII Deficiency; Factor X; Hypoprothrombinemias; Phospholipids; Rabbits; Research; Thromboplastin; Tissue Extracts

Topics: Biomedical Research; Blood Coagulation Factors; Catechols; Dihydroxyphenylalanine; Dopamine; Ellagic Acid; Factor VII Deficiency; Factor XII; Flavonoids; Gallic Acid; Hemophilia A; Hemophilia B; Humans; Lactones; Pharmacology; Prothrombin; Pyrogallol; Research; Serum Globulins; Tannins; Thrombin; Thromboplastin

Topics: Anemia; Exchange Transfusion, Whole Blood; Factor VII Deficiency; Factor VIII; Hemophilia B; Hemorrhagic Disorders; Humans; Hyperbilirubinemia; Hypoprothrombinemias; Infant; Infant, Newborn; Infant, Newborn, Diseases; Prednisone; Scalp; Skull Fractures; Thromboplastin; Vitamin K 1

Topics: Blood Platelet Disorders; Dicumarol; Drug Therapy; Factor V Deficiency; Factor VII Deficiency; Factor VIII; Factor XII; Hemophilia A; Hemophilia B; Hemorrhagic Disorders; Heparin; Humans; Hypoprothrombinemias; Prothrombin; Prothrombin Time; Serum Globulins; Thrombocytopenia; Thromboplastin

Topics: Blood Coagulation Tests; Calcium; Factor VII; Factor VII Deficiency; Humans; Prothrombin; Thrombin; Thromboplastin; Vitamin K Deficiency

Topics: Blood Coagulation; Blood Coagulation Tests; Factor VII Deficiency; Factor VIII; Hemophilia B; Hemorrhagic Disorders; Humans; Hypoprothrombinemias; Prothrombin Time; Thromboplastin