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Biomedical subjects

A Zivelin

Publications and source records attributed to A Zivelin.

At least 55 records · Page 3Linked to original sources
PubMed1996

Plasma PIVKA proteins in rabbits given warfarin.

The presence of partially carboxylated forms of the vitamin K dependent coagulation factors (PIVKA) was evaluated in the plasma of rabbits treated with warfarin. Excess antigen over activity as measured in rabbit specific assays was taken as evidence for PIVKA. Our data confirm a previous report of the absence of plasma PIVKA prothrombin. In contrast, plasma PIVKA factors VII, IX, and X were demonstrable. A striking excess of plasma factor IX antigen over activity was measured and a large fraction of the factor IX antigen persisted in the plasma after its adsorption with barium citrate.

Animals↗
PubMed1995

One of the two common mutations causing factor XI deficiency in Ashkenazi Jews (type II) is also prevalent in Iraqi Jews, who represent the ancient gene pool of Jews.

In recent years four mutations causing factor XI deficiency have been identified in Jews of Ashkenazi (European) origin. Two of them, type II (a nonsense mutation) and type III (a missense mutation), were found to prevail among 125 unrelated Ashkenazi Jews with severe factor XI deficiency. A finding of type II mutation in four unrelated Iraqi-Jewish families raised the possibility that this mutation is also common in Iraqi Jews, who represent the ancient gene pool of the Jews. A molecular-based analysis performed in 1,040 consecutively hospitalized patients disclosed the following results: Among 531 Ashkenazi-Jewish patients, the type II allele frequency was 0.0217 and among 509 Iraqi-Jewish patients, 0.0167 (P = .50). The type III allele frequency in the Ashkenazi-Jewish patients was 0.0254, whereas none of 502 Iraqi-Jewish patients examined had this mutation. These data suggest that the type II mutation was present in Jews already 2.5 millenia ago. The data also indicate that the estimated risk for severe factor XI deficiency in Ashkenazi Jews (due to either genotype) is 0.22% and in Iraqi Jews, 0.03%, and that the estimated risk of heterozygosity in Ashkenazi Jews is 9.0% and in Iraqi Jews, 3.3%. As patients with severe factor XI deficiency are prone to bleeding after injury and patients with partial deficiency may have similar bleeding complications when an additional hemostatic derangement is present, the observed high frequencies should be borne in mind when surgery is planned for individuals belonging to these populations.

Aged↗
PubMed1995

Heparin-induced thrombocytopenia and fatal thrombosis in a patient with activated protein C resistance.

We report a 20-year-old woman who developed heparin-induced thrombocytopenia (HIT) associated with devastating and fatal multiorgan thrombosis. The patient, her mother, and her brother were found to have resistance to activated protein C (APC), and the congenital thrombophilia in this family was verified by the finding of the Arg506 Gln mutation in factor V. This is the first case of HIT and APC resistance. The consequences of this association are discussed.

Adult↗
PubMed1995

Evidence for an essential role of tissue factor dependent blood coagulation in the pathogenesis of the local Shwartzman reaction.

Adherence and aggregation of leukocytes within the vessels of a prepared skin site has been shown to be essential for the pathogenesis of the local Shwartzman reaction (LSR) (Argenbright and Barton: J Clin Invest 89: 259, 1992). We have now performed experiments in rabbits to evaluate whether coagulation within the vessels of a prepared site is a second requirement for the reaction. Skin sites were prepared by an intradermal injection of endotoxin 24 hours before a provoking intravenous injection of endotoxin. Thirteen control rabbits all developed the LSR. Seven of 12 rabbits given warfarin to achieve anticoagulation approximating that used therapeutically in humans before the provoking injection were protected against the LSR (p = 0.003). Five of nine rabbits given anti-rabbit factor X IgG before the provoking injection to yield mean values in individual rabbits of between 7% and 18% plasma factor X activity were protected against the LSR (p = 0.009). Six of 11 rabbits given anti-rabbit factor VII IgG before the provoking injection to yield mean values in individual rabbits of between < 0.5% and 2.2% were protected against the LSR (p = 0.007). Four rabbits failed to develop the LSR at an endotoxin-prepared skin site when an infusion of tissue factor (TF) causing substantial intravascular coagulation was substituted for a provoking injection of endotoxin. It would appear that two events are required for the pathogenesis of the LSR provoked by endotoxin: formation of aggregated masses of WBC in the prepared skin vessels and deposition of fibrin due to TF-initiated coagulation.

Animals↗
PubMed1995

[Resistance to activated protein C--a novel cause of thrombophilia].

A point mutation in coagulation factor V which causes resistance to cleavage of factor Va by activated protein C (APC), was recently found to underlie thrombotic events. We examined 20 consecutive patients, under the age of 40, who suffered from idiopathic venous or arterial thrombosis. In 8 (40%) there was resistance to APC manifested by absence of the expected prolongation of activated partial thromboplastin time (aPTT). In 3, the addition of normal plasma corrected the anomaly in the patient's plasma, although the addition of factor V- deficient plasma caused no change. In a family of a 17-year-old boy with idiopathic deep venous thrombosis we found a mutation in factor V which was responsible for APC resistance. The patient and 4 family members showed a single G to A transition in position 1691 in their cDNA, resulting in substitution of arginine (506) for glutamine. The mutation in this area, which is the cleavage site for APC, is associated with thrombotic episodes and is frequently observed in patients with familial thrombophilia.

Adolescent↗
PubMed1994

Antibody-induced acute factor X deficiency: clinical manifestations and properties of the antibody.

A patient is described with serious bleeding due to a transient selective deficiency of factor X. Crossed immunoelectrophoresis of patient's plasma with anti-factor X antibody revealed an abnormal factor X arc suggestive of the presence of plasma factor X/anti-factor X immune complexes. A similar abnormal arc was obtained on adding the patient's IgG to normal plasma. Immunoblotting of factor X after reduced SDS-PAGE revealed that the patient's IgG bound to the light chain of intact factor X but not Gla-domainless factor X. The patient's IgG inhibited activation of factor X by VIIa/tissue factor (TF), by IXa/VIIIa/phospholipid complex, and by Russell's viper venom. The IgG failed to inhibit the proteolytic activity of factor Xa towards a chromogenic substrate. However, under reaction conditions of limited factor Xa availability, the IgG could be shown to impair hemostatic functions of factor Xa that require the participation of its light chain: activation of prothrombin by prothrombinase; activation of factor VII bound to TF; and inhibition of VIIa/TF activity by factor Xa/tissue factor pathway inhibitor complexes. A few earlier patients have been described with transient, selective factor X deficiency and serious bleeding, but in only one was evidence obtained of an antibody against factor X. It will be of interest to learn whether use of the techniques described in this report will permit the identification of immunoglobulin with similar binding and functional properties in future patients with this rare syndrome.

Aged↗
PubMed1993

Mechanism of the anticoagulant effect of warfarin as evaluated in rabbits by selective depression of individual procoagulant vitamin K-dependent clotting factors.

We have evaluated the contribution of depression of individual procoagulant vitamin K-dependent clotting factors to the ability of warfarin to protect rabbits against tissue factor-induced coagulation. Mean activities of individual procoagulant factors were determined, in assays with rabbit substrates, for a group of rabbits achieving a protective degree of anticoagulation with warfarin. Values were: factor VII, 12%; factor IX, 7%; factor X, 14%, and prothrombin, 13%. The effect upon tissue factor-induced coagulation of selective immunodepletion of each factor to a comparable level was then evaluated. Immunodepletion of plasma factor X or prothrombin, but not of factor VII or factor IX, protected otherwise normal rabbits against tissue factor-induced coagulation. Next, we determined the effect upon the protection in warfarin-treated rabbits of selectively restoring factor X or prothrombin before infusing tissue factor. When either factor was selectively restored, warfarin's protective effect was abolished. Moreover, selective restoration of prothrombin sensitized warfarin-treated rabbits to coagulation more severe than observed in nontreated control rabbits. One may extrapolate from these data that depression of both factor X and prothrombin are required for warfarin's clinical antithrombotic efficacy and that depression of plasma prothrombin is particularly important.

Animals↗
PubMed1992

Clinical significance of antibodies to bovine and human thrombin and factor V after surgical use of bovine thrombin.

Two patients exposed during surgery to bovine thrombin developed antibodies reacting with both bovine and human thrombin and Factor V. Their thrombin times were markedly prolonged with bovine thrombin and modestly prolonged with human thrombin. High titer anti-bovine Factor V created diagnostic confusion in one patient by neutralizing bovine Factor V in a prothrombin assay substrate. Although weaker, antibody activity against human Factor V led to postoperative factor V deficiency in both patients. Such cross-reacting antibodies, recognizable by their higher titer against bovine than human Factor V, should be suspected when a patient surgically exposed to bovine thrombin develops a Factor V anticoagulant after operation. Crossed immunoelectrophoresis of adsorbed bovine plasma with each patient's plasma as antibody revealed many precipitin arcs indicative of immunization of the patients to additional proteins in a commercial thrombin preparation.

Aged↗
PubMed1992

The inheritance of type I and type III von Willebrand's disease in Israel: linkage analysis, carrier detection and prenatal diagnosis using three intragenic restriction fragment length polymorphisms.

Three intragenic restriction fragment length polymorphisms (RFLPs) were used to study linkage and analyse the mode of inheritance in type I and type III von Willebrand's disease (vWD). In two families linkage was established between Sac I RFLPs and the inheritance of type I vWD. RFLP analysis of amniocyte DNA from a potentially affected foetus enabled us to establish a prenatal diagnosis of vWD in a third family with type I vWD. Linkage was also established in four families between the Sac I and two Taq I RFLPs and the inheritance of type III vWD. All type III probands were homozygotes and inherited the same mutant vWF allele from both parents. Heterozygous carriers from one type III family were phenotypically normal and could be detected only by linkage analysis, whereas carriers from the remaining three type III families were asymptomatic but had decreased values of vWF antigen and activity. RFLP-based linkage analysis of vWD alleles provides a way to improve the diagnostic precision, detect carriers, and may be useful for prenatal diagnosis of type III vWD.

Female↗
PubMed1990

Hereditary deficiency of all vitamin K-dependent procoagulants and anticoagulants.

Hereditary combined deficiency of vitamin K-dependent factors is a rare entity. We report a 7-year-old girl of Arab origin with hereditary deficiency of the procoagulants factors II, VII, IX and X and the natural anticoagulants proteins C and S. The patient is the tenth offspring of a consanguinous marriage and presented at 6 weeks with spontaneous intracerebral haemorrhage. Symptoms improved following plasma infusion. A sibling died at 5 d from uncontrollable umbilical bleeding. Blood coagulation work-up at 6 years showed: factor II:C (activity) 12 U/dl, factor II:Ag (antigen) 40 U/dl; factor VII:C 12 U/dl; factor IX:C 36 U/dl, factor IX:Ag 57 U/dl; factor X:C 17 U/dl, factor X:Ag 54 U/dl; protein C activity 43 U/dl; protein C:Ag 45 U/dl; protein S:Ag 34 U/dl; levels of factors V:C and VIII:C were normal. Assays of coagulation factors in the parents and five of the siblings were within the normal range. Following acute infection and dilantin therapy procoagulant activity levels were reduced further and were partially increased after vitamin K infusion. Crossed immunoelectrophoresis of prothrombin in the presence of calcium lactate revealed a population of des-carboxyprothrombin. Serum vitamin K epoxide levels were undetectable. The data suggest that the defect in our patient stems from abnormal carboxylation of the vitamin K-dependent proteins and that the mode of inheritance is autosomal recessive.

Blood Coagulation Disorders↗
PubMed1989

Correlation of baseline plasminogen activator inhibitor activity with patency of the infarct artery after thrombolytic therapy in acute myocardial infarction.

Increased levels of plasminogen activator inhibitor (PAI) have recently been described in patients with acute myocardial infarction (AMI). To correlate PAI levels to patency of infarct arteries after thrombolytic therapy with recombinant tissue-type plasminogen activator (rt-PA), 125 consecutive patients with AMI were examined. Blood levels of fibrinogen, plasminogen, tissue plasminogen activator (t-PA) and PAI were measured before treatment initiation, 10 minutes after completion of rt-PA infusion and 24 and 48 hours after treatment. Coronary angiography, performed in all patients 72 hours after beginning rt-PA infusion, revealed patent infarct arteries in 97 patients and occluded infarct arteries in 28 patients. Pretreatment levels of PAI were significantly higher in patients with occluded infarct arteries (18.0 +/- 11.5 vs 10.5 +/- 9.3 IU/ml, p less than 0.01). Conceivably, higher levels of PAI may interfere with the natural thrombolytic process and make pharmacologic thrombolytic intervention less effective.

Arteries↗
PubMed1989

The relative frequency of hereditary thrombotic disorders among 107 patients with thrombophilia in Israel.

Since most patients with thrombophilia in Israel are referred for diagnosis to our center, it was possible to estimate the relative frequency of the hereditary disorders leading to thrombophilia. 107 unrelated patients were evaluated over 4 years. Diagnoses were established in 23 patients (21.5%) while in 84 (78.5%) no abnormality was detected. Antithrombin III deficiency was found in 8 patients (7.5%), dominant protein C deficiency in 6 (5.6%), recessive homozygous protein C deficiency in 1, protein S deficiency in 3 (2.8%) and dysfibrinogenemia in 1. Four additional patients (3.7%) had a lupus anticoagulant. The frequency of deep vein thrombosis and pulmonary embolism was similar in patients with and without a definite diagnosis. Thrombosis of visceral or cerebral vessels and a positive family history were more frequent among patients in whom a definite diagnosis was made. In both groups there was a substantial lag between the time of presentation of the first thrombotic episode and the time of evaluation. Since the number of referred patients with thrombophilia has gradually increased over the period of the study, it is at present impossible to establish the prevalence of the various hereditary disorders leading to thrombophilia in the population.

Adolescent↗
PubMed1989

Immunoblot analysis of platelet glycoprotein IIb in patients with Glanzmann thrombasthenia in Israel.

Recent studies have indicated that severe ('type I') Glanzmann thrombasthenia is a heterogeneous hereditary disorder caused by quantitative and/or qualitative abnormalities of platelet membrane glycoproteins (GP) IIb and IIIa. Immunoblot analysis of sodium dodecyl sulphate (SDS)-solubilized platelets was carried out on controls and 18 patients (12 Iraqi-Jews, two Iranian Jews and four Arabs) employing three antibodies (one monoclonal and two polyclonal) directed at different sites on GPIIb. Nonreduced control platelet samples contained a major Mr approximately 140k immunoreactive protein that was split into an Mr approximately 120k (alpha) and an Mr approximately 25k (beta) band after reduction with mercaptoethanol. The nonreduced samples from all 18 patients tested had trace amounts of Mr approximately 140k band corresponding to normal GPIIb; the intensity of this band was estimated to be less than 1% of the normal amount. Unlike the control samples, however, this Mr approximately 140k band did not change electrophoretic mobility following reduction. Since GPIIb originates from a single chain precursor molecule of Mr approximately 140k that comprises both the alpha and beta chains, and which does not change mobility with reduction, our data suggest that the platelets of these patients contain small amounts of this precursor.

Antibodies, Monoclonal↗
PubMed1987

Partial purification and characterization of extrinsic pathway inhibitor (the factor Xa-dependent plasma inhibitor of factor VIIa/tissue factor).

We report a procedure to purify partially from plasma (approximately 1200 fold) the factor Xa-dependent inhibitor of factor VIIa/tissue factor (i.e., the extrinsic pathway inhibitor or EPI) and describe some of its properties. An assay for EPI was developed based upon inhibition of factor VIIa/tissue factor induced release of activation peptide from tritiated factor IX by a test sample in the presence but not in the absence of factor Xa. Approximately 50% of the total EPI activity in plasma was found in the lipoprotein fraction, which was used as the starting material for purification. Total lipoproteins (isolated by density ultracentrifugation) were delipidated and the urea soluble apoproteins gel filtered on Sephacryl S-200. The inhibitory activity co-eluted with the major protein peak, which primarily contained apoprotein A-I. Inhibitory activity was separated from apoprotein A-I by anion-exchange chromatography on Q-Sepharose and was further resolved from higher and lower molecular weight contaminating proteins by polypreparative disc gel electrophoresis in the presence of 0.1% SDS. Functional inhibitory activity eluted from the polypreparative disc gel in two discrete pools of different molecular weights (approximately 34,000 and approximately 43,000 D). Apoprotein E was identified by immunological techniques as the major protein present in both of these pools. However, incubation with a monospecific polyclonal antibody to human apoprotein E did not decrease EPI activity either in plasma or in the partially purified polypreparative disc gel fractions. A rabbit antiserum was prepared against material from the polypreparative disc gel. The IgG fraction neutralized approximately 95% of the total inhibitory activity present in plasma. Therefore, EPI in the lipoprotein fraction and in the non-lipoprotein fraction of plasma appears to be antigenically similar.

Blood↗
PubMed1987

A plasma protein C activity assay suitable for a clinical laboratory. Its use to measure activity in hereditary and acquired deficiency states.

The authors describe the technic and standardization of an assay to measure plasma protein C activity feasible for clinical laboratory use. It is modified from an assay of Francis and Patch (Thromb Res 1983; 32:605-613) to enhance protein C recovery in the barium citrate eluate, to eliminate the steps of addition and neutralization of heparin, and to use only commercially available reagents. The normal range for plasma protein C in the assay is 72-130% (+/- 2 SD) (0.7-1.30). Hepatocellular disease lengthening the prothrombin time by 3-4 seconds was associated with plasma protein C activity of 25% (0.25) to 35% (0.35). Although the assay is thought to accurately measure protein C activity in patients taking warfarin, one cannot evaluate such patients for hereditary functional protein C deficiency because treatment with warfarin will itself reduce the ratio of protein C activity to antigen. The assay can be used in a patient receiving heparin if the heparin is removed as described.

Antithrombin III↗
PubMed1986

A relatively high frequency of severe (type III) von Willebrand's disease in Israel.

Sixty patients with von Willebrand's disease belonging to 34 unrelated families were classified into the various types of the disease by analysis of the multimer patterns of von Willebrand factor. Type I disease was observed in 62% of the families, a finding similar to the recently published British and Swedish series of patients. Type III (severe) von Willebrand's disease was observed more frequently in the Israeli group (29%) than in the other two series. Of the 16 patients with type III disease eight were Arabs living in Israel, the West Bank and the Gaza Strip (total population about 1.5 X 10(6). Thus, it appears that the frequency of type III disease is very high among Arabs (5.3/10(6]. Sibship analysis of all families affected by the type III mutant gene was compatible with an autosomal recessive mode of inheritance. An attempt was made to define carriers of type III disease and to distinguish them from type I patients and from healthy subjects. In 15 obligate carriers of type III disease mean levels of factor VIII clotting activity, of von Willebrand factor and of ristocetin cofactor were significantly higher than the corresponding mean values observed in 31 symptomatic and 12 asymptomatic type I patients, and in turn significantly lower than the corresponding mean values observed in 30 healthy subjects. Ristocetin cofactor was the best criterion for discrimination among carriers of type III disease, normal subjects and type I patients.

Blood Coagulation Tests↗