bluuebunny/crossref_metadata_2025 huggingface dataset:
Quality of life in venous disease
Authors: Vossen Carla , Rosendaal Frits , Cameron Linda , Bovill Edwin , Kaptein Adrian , van Korlaar Inez
Published: March 2018

Quality of life (QOL) can be defined as the functional effect of an illness and its consequent therapy upon a patient, as perceived by the patient. Studies on the impact of chronic venous disease on quality of life are scarce compared to quality of life research in other diseases. The purpose of this paper was to describe instruments that assess the quality of life in patients with chronic venous disease and to review the literature on this topic.

A computer search of the MedLine database was performed to identify papers; the bibliographies of relevant articles were reviewed to obtain additional papers. Papers were included if they described the development or use of a quality of life instrument for patients with chronic venous disease.

A total of 25 papers were identified that fit the inclusion criteria. The studies described in the papers used six different generic instruments and ten disease-specific instruments. Quality of life in chronic venous disease was assessed in 12 studies. Six studies compared different types of treatment for chronic venous disease where QOL was an outcome measure. Despite the wide variety of measures used, results indicate that the quality of life of patients with chronic venous disease is affected in the physical domain mostly with regard to pain, physical functioning and mobility, and that they suffer from negative emotional reactions and social isolation.

We feel that QOL should be a standard measure in future studies in patients with chronic venous disease, preferably with a combination of generic and disease-specific measures.
Contraceptive pills induce an improvement in congenital hypoplasminogenemia in two unrelated patients with ligneous conjunctivitis
Authors: Saggiorato Graziella , Pellati Donatella , Casonato Alessandra , Spiezia Luca , Pontara Elena , Gavasso Sabrina , Girolami Antonio , Sartori Maria
Published: March 2018

Severe type I plasminogen deficiency is the underlying cause of ligneous conjunctivitis, a rare disease characterized by wood-like pseudomembranes developing on the ocular and extraocular mucosa. Two unrelated female patients with ligneous conjunctivitis and moderate hypoplasminogenemia are described. Being of fertile age, they were treated with oral contraceptives, which determined a marked increase in plasminogen levels. Moreover, a palpebral pseudomembrane stopped growing in one patient and disappeared completely in the other while on the estroprogestinic treatment. In patient n.2,who also suffered from von Willebrand’s disease, prior Cushing’s disease induced an increase in both von Willebrand factor and plasminogen levels, which dropped after curative hypophysectomy. Genetic plasminogen study showed a 19Lys>Glu mutation in a heterozygous state in the first proposita and in a homozygous state in the second proband. In addition, both index patients were homozygous for a new intron F-14T>G mutation, which was found to reduce the acceptor splicing site prediction score.

In conclusion, oral contraceptive therapy may improve plasminogen deficiency and deserves attention as an alternative therapeutic approach in selected cases of ligneous conjunctivitis with low, but not absent, plasminogen synthesis.
Quality of life and the duration of treatment with vitamin K antagonists in patients with deep venous thrombosis
Authors: Sprangers Mirjam , de Haes Hanneke , Büller Harry , Prins Martin , Locadia Mirjam
Published: March 2018

In clinical practice, decisions on the duration of treatment with vitamin K antagonists are usually based on the presence of persistent risk factors, the risk of bleeding and centre policy. Little is known about the influence of patients’ experienced quality of life. The objectives of this study were: 1) to explore the course of quality of life in patients with venous thrombosis treated for 3 months versus patients treated for 6 months with vitamin K antagonists; 2) to investigate the factors that were associated with the duration of treatment with vitamin K antagonists. The study sample comprised patients participating in a multi-centre clinical trial. Quality of life was assessed at study entry, after 10-14 days,3 and 6 months in 360 patients. Overall, no dif-ferences in quality of life were found between the 2 patient groups. An interaction effect between group and time was found for physical functioning. Regression analyses indicated that the presence of one or more permanent risk factors, duration of hospitalisation, mobility prior to deep-vein thrombosis and study centre were associated with the duration of treatment with vitamin K antagonists. Interestingly, quality of life was not associated with treatment duration. Since study centre was the most important factor associated with treatment duration, local policy appears to have a great influence on decisions regarding the duration of treatment with vitamin K antagonists.

Part of this manuscript has been included in a poster presentation at the International Society for Quality of Life Research in Amsterdam, The Netherlands, November 8, 2001.
Derivation of a Simple Clinical Model to Categorize Patients Probability of Pulmonary Embolism: Increasing the Models Utility with the SimpliRED D-dimer
Authors: Anderson David , Rodger Marc , Ginsberg Jeffrey , Kearon Clive , Gent Michael , Turpie Alexander , Bormanis Janis , Weitz Jeffrey , Chamberlain Michael , Bowie Dennis , Barnes David , Hirsh Jack , Wells Philip
Published: March 2018

We have previously demonstrated that a clinical model can be safely used in a management strategy in patients with suspected pulmonary embolism (PE). We sought to simplify the clinical model and determine a scoring system, that when combined with D-dimer results, would safely exclude PE without the need for other tests, in a large proportion of patients. We used a randomly selected sample of 80% of the patients that participated in a prospective cohort study of patients with suspected PE to perform a logistic regression analysis on 40 clinical variables to create a simple clinical prediction rule. Cut points on the new rule were determined to create two scoring systems. In the first scoring system patients were classified as having low, moderate and high probability of PE with the proportions being similar to those determined in our original study. The second system was designed to create two categories, PE likely and unlikely. The goal in the latter was that PE unlikely patients with a negative D-dimer result would have PE in less than 2% of cases. The proportion of patients with PE in each category was determined overall and according to a positive or negative SimpliRED D-dimer result. After these determinations we applied the models to the remaining 20% of patients as a validation of the results. The following seven variables and assigned scores (in brackets) were included in the clinical prediction rule: Clinical symptoms of DVT (3.0), no alternative diagnosis (3.0), heart rate >100 (1.5), immobilization or surgery in the previous four weeks (1.5), previous DVT/PE (1.5), hemoptysis (1.0) and malignancy (1.0). Patients were considered low probability if the score was <2.0, moderate of the score was 2.0 to 6.0 and high if the score was over 6.0. Pulmonary embolism unlikely was assigned to patients with scores <4.0 and PE likely if the score was >4.0. 7.8% of patients with scores of less than or equal to 4 had PE but if the D-dimer was negative in these patients the rate of PE was only 2.2% (95% CI = 1.0% to 4.0%) in the derivation set and 1.7% in the validation set.

Importantly this combination occurred in 46% of our study patients. A score of <2.0 and a negative D-dimer results in a PE rate of 1.5% (95% CI = 0.4% to 3.7%) in the derivation set and 2.7% (95% CI = 0.3% to 9.0%) in the validation set and only occurred in 29% of patients. The combination of a score <4.0 by our simple clinical prediction rule and a negative SimpliRED D-Dimer result may safely exclude PE in a large proportion of patients with suspected PE.
A Novel Approach to the Assessment of Variations in the Human Platelet Count
Authors: James John , Brown Dianne , Whyte Gordon , Dean Mark , Chesterman Colin , Donald Jennifer , Buckley Michael
Published: March 2018

This is the first report of a method to assess the significance of numerical changes in the platelet count based upon a result exceeding the normal intra-individual variation in platelet numbers. Serial platelet counts from 3,789 subjects were analysed to determine the intra-individual variation in platelet numbers. A platelet count difference of 98 × 109/L in males was found to represent a change that would occur by chance in less than 1 in 1,000 platelet count determinations. Tables to determine the significance of platelet number variations, given N previous observations, are provided at two probability levels. The repeatability of the platelet count was calculated as 0.871 (males) and 0.849 (females) indicating that the heritability of platelet count is high and that the platelet count is predominantly genetically determined. A seasonal variation in platelet count was found with a ‘winter’ versus ‘summer’ difference of 5.10 × 109/L (males) and 5.82 × 109/L (females).
A Comparison of the Safety and Efficacy of Oral Antiocoagulation for the Treatment of Venous Thromboembolic Disease in Patients with or without Malignancy
Authors: Legnani Cristina , Lee Agnes , Manotti Cesare , Hirsh Jack , D’Angelo Armando , Pengo Vittorio , Moia Marco , Coccheri Sergio , Palareti Gualtiero
Published: March 2018

The optimal long-term treatment of acute venous thromboembolism (VTE) in patients with malignancy remains undefined. In particular, based on current evidence, it is uncertain whether secondary prophylaxis using standard intensity oral anticoagulant therapy is associated with higher risks of bleeding and recurrent thrombosis in patients with cancer than in those without cancer. This study compared the outcome of anticoagulation courses in 95 patients with malignancy with those of 733 patients without malignancy. All patients were participants in a large, nation-wide population study and were prospectively followed from the initiation of their oral anticoagulant therapy.

Based on 744 patient-years of treatment and follow-up, the rates of major (5.4% vs 0.9%), minor (16.2% vs 3.6%) and total (21.6% vs 4.5%) bleeding were statistically significantly higher in cancer patients compared with patients without cancer. Bleeding was also a more frequent cause of early anticoagulation withdrawal in patients with malignancy (4.2% vs. 0.7%; p <0.01; RR 6.2 (95%CI 1.95-19.4). There was a trend towards a higher rate of thrombotic complications in cancer patients (6.8% vs. 2.5%; p = 0.058; RR 2.5 [CI 0.96-6.5]) but this did not achieve statistical significance. In the group of patients with cancer, the bleeding rate was high across the different INR categories and was independent of the temporally associated International Normalized Ratio (INR). In contrast, the bleeding rate was increased only with INR values greater than 4.5 in the group of patients without cancer. The rate of thrombotic events was significantly higher in both cohorts when the INR was less than 2.0.

In conclusion, patients with malignancy treated with oral anticoagulants have a higher rate of bleeding and possibly an increased risk of recurrent thrombosis compared with patients without malignancy. Safer and more effective anticoagulant therapy is needed for this challenging group of patients.
The VITA Project: Heritability of Resistance to Activated Protein C
Authors: Tosetto Alberto , Castaman Giancarlo , Cappellari Antonio , Rodeghiero Francesco
Published: March 2018

Resistance to activated protein C (APC) is a risk factor for venous thromboembolism also in absence of the FV Leiden mutation. To evaluate the influence of genetic factors on APC resistance, we evaluated the heritability of the APC resistance phenotype in 1,519 sib-parent pairs randomly selected from the VITA Project. After adjustment for known influencing factors, a high heritability coefficient (0.58) was observed and parental response to APC was the single most important factor in predicting the corresponding phenotype in sibs. In 32 parentsib pairs in which phenotypic resistance to APC unrelated to FV Leiden was present in both parents and sibs, no additional mutation on the 306-aminoacid residue of FV (FV Cambridge and FV Hong Kong) was found. In these 32 parent-sib pairs, FVIII:C and vWf:Ag levels were not significantly increased and there was no excess prevalence of the R2 allele of exon 13 of FV gene. This study suggests that the response to APC is significantly influenced by genetic factors also at a population level, but the responsible mechanisms are still undefined.
The HR2 Haplotype of Factor V Is not Associated with the Risk of Myocardial Infarction
Authors: Doggen Carine , de Visser Marieke , Vos Hans , Bertina Rogier , Cats Volkert , Rosendaal Frits
Published: March 2018

The HR2 haplotype of the factor V gene, which contains the histidine to arginine substitution at position 1299, has been reported to be associated with reduced factor V levels. Because high factor V levels have been found to be associated with an increased risk of myocardial infarction, we examined how the presence of the R2 allele affected the risk of myocardial infarction in the case-control “Study of Myocardial Infarctions Leiden”.

Among 560 men with a first myocardial infarction before the age of 70 years, 9.5% were heterozygous carriers of the R2 allele. The control group consisted of 646 men, in which 9.9% were heterozygous and 0.2% homozygous carriers of the R2 allele. The risk of myocardial infarction in the presence of the R2 allele was not increased (odds ratio, 0.9; 95% confidence interval 0.6 to 1.4). Exclusion of factor V Leiden carriers did not change this result. The risk was 4.4-fold increased for smokers who carried the R2 allele compared to non-smoking noncarriers. No synergy was found between metabolic risk factors and the presence of the R2 allele.

We conclude that the risk of myocardial infarction for men in the presence of the R2 allele of the His1299Arg polymorphism is neither increased nor decreased.
The Procoagulant State of the VX-2 Tumor in Rabbit Lung In Vivo
Authors: Ross Bonnie , Bardossy Leslie , Southward Suzanne , DeReske Marnie , Richardson Mary , Blajchman Morris , Hatton Mark
Published: March 2018

During their growth, many malignant solid tumors elicit a hemostatic response in the host. In this report, the fluxes of various rabbit plasma hemostatic proteins into pulmonary VX-2 tumors have been measured in vivo. VX-2 cells were contained within a small rabbit plasma clot which was injected intravenously into rabbits. At 28 d, each rabbit was injected intravenously with two radiolabeled (131I, 125I) proteins selected from fibrinogen, prothrombin, antithrombin-α, heparin cofactor II, or plasminogen-I or -II. After allowing the labeled proteins to circulate for 10-200 min, each rabbit was perfused with Krebs-Henseleit solution and the lungs excised. Solid tumors were isolated, weighed and measured for radioactivity content. A mean of 14 tumors/pair of lungs with a mean tumor weight of 0.3 g was obtained. Radioactivity per g of tumor was related to radioactivity/ml of blood at exsanguination for each protein at each time interval. Maximum flux rates were calculated (as pmol/g of tumor/min): Fibrinogen, 65.0; prothrombin, 53.0; antithrombin-α, 24.1; HCII, 17.2; plasminogen-II, 5.0; and plasminogen-I, 3.2. Using immunocytochemical staining, fibrin(ogen) was distributed heterogeneously within the VX-2 tumor, appearing largely in the perinodular region and in the necrotic core. From the net fluxes of these proteins, the profile of chronic hemostasis associated with the VX-2 tumor was shown to differ markedly from the hemostatic response that occurs after an acute vascular injury.
The Identification of Polymorphisms in the Coding Region of the Apolipoprotein (a) Gene
Authors: Leus Frank , Bouma Bonno , van Rijn Herman , Prins Janke
Published: March 2018

Lipoprotein (a) [Lp(a)] is a quantitative genetic trait in human plasma and elevated levels represent a major inherited risk factor for the development of atherosclerotic disease. In our search for sequence polymorphisms in the coding region of the apolipoprotein(a) [apo(a)] gene that may affect the Lp(a) concentration, four new polymorphic sites were identified. These include two coinciding polymorphisms with an allele frequency of 38% located at amino acid positions 87 and 101 (Leu87,101 →Val) in the interkringle region of kringle IV (K.IV) type 7 and two polymorphisms located in K.IV type 7 (Arg60 →Ser) and in K.IV type 10 (Tyr2 →Phe) both with estimated allele frequencies of about 1%.

The linkage between the newly identified K.IV type 7 Leu87,101 →Val polymorphism and earlier described polymorphic sites in the non-coding and coding regions of the apo(a) gene, its distribution over the apo(a) isoform sizes and its possible influence on the Lp(a) concentration was analysed in 201 healthy unrelated Caucasians. The earlier described polymorphic sites included in this study were the variable number of a TTTTA pentanucleotide repeat (7-11 PNR) starting at -1231 bp, the -772 bp G/A polymorphism, the +93 bp C/T polymorphism and the +121 bp G/A polymorphism in the non-coding region, and the K.IV type 8 Thr12/Pro polymorphism and the K.IV type 10 Thr66/Met polymorphism in the coding region of the apo(a) gene.

Linkage disequilibria were observed between the polymorphic sites in the 5’ non-coding region and the sites in K.IV type 7 and 8 in the coding region of the apo(a) gene, confirming that the expansion of the variable number of K.IV type 2 repeats results from intrachromosomal recombinational events. The distribution over the apo(a) isoform sizes of the K.IV type 7 Val87,101 subtype was not significantly different from that of the K.IV type 7 Leu87,101 wild-type, suggesting a relative ancient mutational event. No influence of the K.IV type 7 Leu87,101 →Val polymorphism on the Lp(a) level was observed. In fact, of all the polymorphic sites studied, only the +121 A subtype could be associated with an increased, and the K.IV type 8 Pro12 and the 10 PNR subtypes with a reduced, Lp(a) concentration corrected for apo(a) isoform size (p <0.05).
A Longitudinal Study of the Factor VII Rise during Pregnancy
Authors: Wright D. , Thomson J. M. , Sidebotham A. , Hirst C. F. , Hirsch P. , Poller L.
Published: March 2018

A longitudinal study of 21 pregnant women has been undertaken using a variety of factor VII assays, including factor VIIa, to investigate the increase of factor VIIc. All assays demonstrated significant rises (p <0.001), most marked for factor VIIa (82%) and factor VIIc rabbit (81%). Smaller rises were seen for factor VIIc bovine (50%) and VII antigen (40%). Three indirect measures of activity state, factor VIIc rabbit:antigen, bovine:antigen and bovine:rabbit, provided conflicting data. Factor VIIa:antigen showed a significant increase of 36% (p <0.001). Within individual pregnancies the change in factor VIIc rabbit and antigen correlated with maternal weight gain (p <0.05). Two activity state measures, bovine:rabbit and bovine:antigen, showed negative correlation with birthweight. The increases in both zymogen and in activity state appear to contribute to the factor VIIc rise. The extent of this rise appears to be influenced by maternal weight gain. Increased factor VII activation is associated with reduced foetal growth.
The Influence of a Serine Protease Inhibitor, Nafamostat Mesilate, on Plasma Coagulation, and Platelet Activation during Experimental Extracorporeal Life Support (ECLS)
Authors: Skogby Maria , Friberg Lars Göran , Tengborn Lilian , Wadenvik Hans , Mellgren Karin
Published: March 2018

Introduction: During extracorporeal circulation the contact between blood and the artificial surface of the circuit induces several changes in the hemostatic system. The objective of the present study was to assess the effect of a serine protease inhibitor – Nafamostat mesilate (FUT-175) – on coagulation and on platelets during experimental extracorpo-real circulation. Methods: Two identical Extra Corporeal Life Support (ECLS) circuits were primed with fresh, heparinized human blood and circulated for 24 h. FUT-175 was added to one of the paired circuits and the other was used as a control. The following FUT-175 concentrations were employed: (1) 7.1 mg/l/h, (2) 14.2 mg/l/h, (3) 14.2 mg/l/h + 85.5 mg given as an initial bolus, (4) 28.5 mg/l/h + 171 mg given as an initial bolus. Blood samples were collected from the circuits before the start of the perfusion and at 0.5, 1, 3, 12, and 24 h of perfusion, and analysed for platelet count, plasma betathromboglobulin ( -TG), platelet membrane glycoprotein (GP) Ib and GPIIb/IIIa expression, thrombin/ antithrombin III complex (TAT), prothrombin fragment 1+2 (F1+2), fibrinogen, D-dimer, and plasminogen activator inhibitor 1 activity (PAI-1). Results: Significantly higher platelet membrane GPIb expression and lower plasma -thromboglobulin levels were observed in the circuits holding FUT-175, suggesting a lower degree of platelet activation. Also, a reduced activation of the coagulation system was observed in the “FUT-circuits”, as reflected by the levels of F1+2 and TAT, and the PAI-1 activity that was rapidly inactivated. Conclusion: FUT-175 reduces the activation of platelets and plasma coagulation in an in vitro ECLS model.
Polymorphism of the Platelet Glycoprotein IIIa Gene in Patients with Coronary Stenosis
Authors: Gonzalez-Lamuño Domingo , Hernandez-Estefania Rafael , Colman Thierry , Pocovi Miguel , Delgado-Rodriguez Miguel , Garcia-Fuentes Miguel , Revuelta Jose , Garcia-Ribes Miguel
Published: March 2018

Based on genetic variability, structural differences in the glycoprotein IIb/IIIa platelet receptor for adhesive proteins result in individual differences in the thrombogenicity of platelets. Recent studies suggest a controversial association between a genetic polymorphism of the glycoprotein IIIa gene (PlA2) and the risk of coronary artery disease. In our study, the prevalence of the PlA2 allele in a group of patients undergoing percutaneous coronary revascularization was 37%, a value significantly higher than in controls [13%, odds ratio (OR) = 3.93, 95% CI, 1.84 to 8.53] suggesting a significant association between this polymorphism and documented coronary stenosis, which is strongest among <60 years old patients (OR = 12.30, 95% CI, 2.98 to 70.93). This polymorphism represents an inherited risk factor for severe cardiovascular disease due to coronary occlusion.
Comparison of a Synthetic Antithrombin III-binding Pentasaccharide and Standard Heparin as an Adjunct to Coronary Thrombolysis
Authors: Pislaru Sorin , Pislaru Cristina , Zhu Xu , Arnout Jef , Stassen Tony , Vanhove Philippe , Herbert Jean-Marc , Meuleman Dirk , Van de Werf Frans
Published: March 2018

The effects on alteplase-induced thrombolysis of the synthetic ATIII-binding pentasaccharide SR90107A/ORG 31540 (synthetic pentasaccharide, SP) and of standard heparin (SH) were compared in a copper coil model of coronary artery thrombosis in 6 groups of 10 dogs. After 1 h of occlusion, all animals received intravenously alteplase and aspirin, and were randomly assigned to a 2 h infusion of either saline, or one of two doses of SH (100 IU/kg bolus plus 50 IU/kg/h infusion, or 200 IU/kg bolus plus 100 IU/kg/h infusion), or one of three doses of SP (100 nmol/kg bolus plus 50 nmol/kg/h infusion, 200 nmol/kg bolus plus 100 nmol/kg/h infusion, or 400 nmol/kg bolus plus 200 nmol/kg/h infusion). Coronary angiography was performed every 10 min for 4 h. Appropriate doses of SP and SH enhanced alteplase-induced thrombolysis to a similar extent. In contrast, SP was devoid of any anti-IIa activity or aPTT prolongation.
Type 2N von Willebrand Disease: Rapid Genetic Diagnosis of G2811A (R854Q), C2696T (R816W), T2701A (H817Q) and G2823T (C858F) – Detection of a Novel Candidate Type 2N Mutation: C2810T (R854W)
Authors: Standen G. R. , Mazurier C. , Gaucher C. , Cumming A. , Keeney S. , Bidwell J. , Bowen D. J.
Published: March 2018

The majority of patients with type 2N von Willebrand disease (VWD type 2N) have mutations in the region of the von Willebrand factor (VWF) gene encoding the factor VIII binding domain of VWF. Two mutations predominate among VWD type 2N patients: G2811A and C2696T, which respectively bring about the amino acid substitutions R854Q and R816W in VWF. Several other mutations have been found in VWD type 2N, including T2701A (H817Q) and G2823T (C858F). We have developed a genetic test which permits rapid screening for these four mutations in a single polymerase chain reaction (PCR). The test employs induced heteroduplex formation using two universal heteroduplex generators, one of which detects G2811A (R854Q) and G2823T (C858F), the other detects C2696T (R816W) and T2701A (H817Q). The allele frequency of the common G2811A (R854Q) mutation was investigated in the local (S. Wales) population by examination of 216 VWF genes (108 individuals) and was found to be 0.01. The heteroduplex-based test additionally detected a novel candidate type 2N mutation, C2810T (R854W) and a previously described polymorphism, G2805A (R852Q). The polymorphism showed allele frequencies of 0.92 (G nucleotide) and 0.08 (A nucleotide) in the population study.
A Ser162→ Leu Mutation within Glycoprotein (GP) IIIa (Integrin β3) Results in an Unstable αIIbβ3 Complex that Retains Partial Function in a Novel Form of Type II Glanzmann Thrombasthenia
Authors: Jackson Denise , White Melanie , Jennings Lisa K. , Newman Peter
Published: March 2018

Platelets from Glanzmann thrombasthenia patient BL express approximately 30% of the normal αIIbβ3 content and support fibrin-mediated clot retraction, but fail to bind fibrinogen or aggregate following cellular activation. BL platelets bind neither activation-dependent nor activation-independent ligands. DNA sequence analysis of BL platelet mRNA revealed a homozygous C583→T point mutation in a conserved region of β3, resulting in a Ser162Leu amino acid substitution. This mutation appears to produce destabilizing effects on the αIIbβ3 complex, as evidenced by the fact that (1) the BL αIIbβ3 complex exhibited altered sedimentation velocity through sucrose gradients, (2) αIIb and β3 was not recognized by complex-dependent monoclonal antibodies or co-precipitated by integrin subunit-specific antibodies, and (3) biosynthesis and trafficking of the αIIbβ3Leu162 complex was delayed relative to that of the wild-type control. Taken together, these data implicate the region encompassing Ser162 in the stabilization and ligand binding properties of the αIIbβ3 complex.
Cloning and Characterization of a cDNA Encoding Murine Coagulation Factor X
Authors: Liang Zhong , Cooper Adrian , DeFord Melanie , Carmeliet Peter , Collen Desire , Rosen Elliot , Castellino Francis
Published: March 2018

The cDNA encoding murine coagulation factor X (fX) was isolated and reconstructed from a λZap cDNA library generated from murine liver mRNA. The cDNA contains 1486 bases starting at the 5’-translation initiation codon. It includes an open reading frame of 1443 nucleotides, followed by an 18 residue 3’ nontranslated sequence downstream of the first stop codon, and a 3’ poly(A) tail. The translation product is composed of a 40-amino acid signal/propeptide region followed by a 441-residue mature protein. The latter is highly homologous to that of human and rat fX. All protein domains of human and rat fX are strictly conserved in mouse fX. The cDNA coding for mouse fX has been expressed in human embryonic kidney 293 cells and generates fX activity measured in a clotting assay using human fX-deficient plasma.
Is Plasminogen Deficiency a Thrombotic Risk Factor ? – A Study on 23 Thrombophilic Patients and their Family Members
Authors: Sulzer I. , Stucki B. , Wuillemin W. A. , Furlan M. , Lämmle B. , Biasiutti F. Demarmels
Published: March 2018

The role of plasminogen (plg) deficiency in the pathogenesis of venous thromboembolism is debated in the literature. In the present study we evaluated the prevalence of plg deficiency in our thrombophilia patients and aimed to elucidate the thrombosis risk of plg deficiency as a single defect or in combination with other defects, with special focus on APC resistance.

The study cohort included 1192 consecutive patients with a history of clinically or objectively diagnosed venous and/or arterial thromboembolism and/or positive family history who were referred to our department for thrombophilia investigation from 02/1988 to 03/1997. All available family members of patients with plg deficiency were tested for plg, APC resistance and other thrombophilic defects that were established in the propositus.

23/1192 propositi were plg-deficient corresponding to an overall prevalence of 1.9%, i.e. 2.2% in patients with venous thrombosis and 1.4% in those with arterial events. Out of the 23 plg-deficient propositi, 8 showed one or multiple additional thrombophilic defects, and in 4 patients relevant circumstantial risk factors were present. Of the 53 available family members, 28 were plg-deficient including 5 with additional APC resistance, and 4 subjects had isolated APC resistance. Ten of the 53 family members had already suffered thromboembolic events, i.e. 5 (18%) in the plg-deficient group and 5 (20%) in the non-deficient group, both groups showing an almost identical median age at the time of investigation (28.9 years and 27.1 years, respectively).

Based on our data, plg deficiency is a rare defect in thrombophilic patients and as a single defect it does not seem to be a strong thrombotic risk factor, as 11 of 23 propositi had additional thrombophilic defects or circumstantial risk factors, and in the family members thrombotic events were equally frequent in the plg-deficient and non-deficient subjects.
Chrono-lume® and Magnesium Potentiate Aggregation of Canine but not Human Platelets in Citrated Platelet-Rich Plasma
Authors: Shofer Frances , Wojenski Carol , Giger Urs , Callan Mary Beth
Published: March 2018

The effects of Chrono-lume® (CL) and magnesium sulfate (Mg2+), a component of this luciferin-luciferase reagent, on platelet aggregation were studied in platelet-rich plasma (PRP) obtained from blood anticoagulated with sodium citrate from humans, dogs, cats, horses, and cows. The final added Mg2+ concentration of both solutions ranged from 0.75-3.7 mM. CL and Mg2+ had no effect on maximum aggregation of platelets from humans induced by sub-threshold concentrations of collagen and ADP. In contrast, addition of CL or Mg2+ to canine PRP resulted in a dose-dependent and equal potentiation of platelet aggregation in response to sub-threshold concentrations of collagen, ADP, and thrombin in normal and thrombopathic dogs. The effect of CL on platelet aggregation induced by sub-threshold concentrations of agonists was less pronounced and varied in other species according to the agonist. The reason for the marked difference in sensitivity of human and canine platelets to CL or Mg2+ is not clear, although a difference in releasable cation pools of the platelets from these two species has been recognized. Platelet aggregation studies of animals with suspected thrombopathias should be performed without CL to prevent masking of a platelet function defect.
Development of an Anti-Bleeding Agent for Recombinant Hirudin Induced Skin Bleeding in the Pig
Authors: Nicolay Uwe , Friesen Heinz-Jürgen , Reers Martin , Dickneite Gerhard
Published: March 2018

Recombinant hirudin (rH) is a highly specific thrombin inhibitor which is under clinical investigation for various thrombotic disorders. However, one of its potential risks during clinical use might be hemorrhage, especially when combined with other agents interfering with the coagulation system like antiplatelet or fibrinolytic agents. In this experimental study we investigated whether Haemate, a von Willebrand Factor (vWF) and factor VIII containing product, could correct rH/aspirin induced bleeding in an experimental pig study. Skin bleeding time was evaluated in three open, placebo-controlled, randomized studies following comparable designs. A total of 62 animals were given a short-term infusion of aspirin (20 mg/kg) followed by a three-hour infusion of a high or low dose (0.3 or 0.5 mg/kg/h) of rH. At cessation of rH infusion, animals were allocated to treatment with either Haemate (30 FVIII U/kg) or the recombinant factor VIII, Helixate, which is devoid of vWF. The skin bleeding time (SBT, given as times of baseline) as measured four hours after the start of the rH infusion was defined as the prospective endpoint.

In study 1 (low dose rH + Haemate) 4 h SBT was 2.18 (placebo) and 1.61 (Haemate, p = 0.0111). In study No. 2 (high dose rH + Haemate) SBT was 2.58 in placebo and 1.73 in Haemate (p = 0.0001). No significant difference between placebo and treatment were detected in study No. 3 (low dose rH + Helixate). Haemate but not Helixate significantly decreased bleeding time as compared to placebo at termination of the study (7 hours) which was defined as the secondary endpoint. No effect on either aPTT nor rH plasma levels were observed with any of the study drugs. It was concluded that Haemate decreases excess bleeding induced by rH/aspirin treatment without altering rH’s anticoagulant effect.
Augmented Platelet Aggregation as Predictor of Reocclusion after Thrombolysis in Acute Myocardial Infarction
Authors: Moser Martin , Kohler Benedikt , Ruef Johannes , Peter Karlheinz , Kübler Wolfgang , Bode Christoph , Nordt Thomas
Published: March 2018

Rationale. Reocclusion after thrombolysis diminishes the benefits of early reperfusion after acute myocardial infarction (AMI). No clinical or laboratory variables have been identified as predictors for reocclusion yet. Methods and results. To evaluate hemostatic variables as potential risk determinants platelet aggregation (PA, representing platelet activity), thrombin/antithrombin complexes (TAT, representing thrombin generation), and plasminogen activator inhibitor type 1 (PAI-1, representing endogenous fibrinolysis) were determined in 31 patients with AMI at 0, 1, 2, and 12 h after the start of thrombolysis as well as at hospital discharge. Reocclusion (defined as reinfarction or angiographically confirmed, clinically silent coronary reocclusion) occurred in 5 patients within 5-14 days and in 8 patients within 1 year. TAT plasma concentrations were lower in patients with reocclusion than in those without (9.9 ± 5.7 vs. 22.9 ± 22.2 ng/ml at 2 h, 6.5 ± 3.1 vs. 11.2 ± 6.4 ng/ml at 12 h, means ± SD, p <0.05 each). Neither concentration nor activity of PAI-1 in plasma differed between both patient groups. However, both slope and maximum of PA (induced by 2 μmol/l ADP) were augmented in patients with reocclusion (slope: 39.4 ± 1.7 vs. 32.5 ± 7.4 at 2 h, p <0.001; 42.6 ± 2.6 vs. 36.6 ± 8.9 at 12 h, p <0.01). Results were independent of the thrombolytic agent used (alteplase or reteplase). A PA slope at 2 h higher than the average slope before thrombolysis (37.2 ± 5.7) could be identified as best predictor for early (within 5-14 d, p = 0.017, sensitivity 1.00, specificity 0.69) and late reocclusion (within 1 y, p=0.009, 0.88 and 0.74, respectively). Conclusions. Increased PA following coronary thrombolysis appears to be associated with early and late reocclusion. This marker could be useful in identifying patients who may benefit from more aggressive anti-platelet (such as GP IIb/IIIa receptor antagonists), interventional, or both strategies.
A Cost-effectiveness Analysis of Aspirin versus Oral Anticoagulants after Acute Myocardial Infarction in Italy
Authors: Gianetti Jacopo , Gensini Gianfranco , Caterina Raffaele De
Published: March 2018

Aims. The recent publication of two large trials of secondary prevention of coronary artery disease with oral anticoagulants (WARIS and ASPECT) has caused a revival of the interest for this antithrombotic therapy in a clinical setting where the use of aspirin is common medical practice. Despite this, the preferential use of aspirin has been supported by an American cost-effectiveness analysis (JAMA 1995; 273: 965). Methods and Results. Using the same parameters used in that analysis and incidence of events from the Antiplatelet Trialists Collaboration and the ASPECT study, we re-evaluated the economic odds in favor of aspirin or oral anticoagulants in the Italian Health System, which differs significantly in cost allocation from the United States system and is, conversely, similar to other European settings. Recalculated costs associated with each therapy were 2,150 ECU/ patient/year for oral anticoagulants and 2,187 ECU/patient/year for aspirin. In our analysis, the higher costs of oral anticoagulants versus aspirin due to a moderate excess of bleeding (about 10 ECU/ patient/year) and the monitoring of therapy (168 ECU/ patient/year) are more than offset by an alleged savings for recurrent ischemic syndromes and interventional procedures (249 ECU/ patient/year). Conclusions. Preference of aspirin vs. oral anticoagulants in a pharmaco-economical perspective is highly dependent on the geographical situation whereupon calculations are based. On a pure cost-effectiveness basis, and in the absence of data of direct comparisons between aspirin alone versus I.N.R.-adjusted oral anticoagulants, the latter are not more expensive than aspirin in Italy and, by cost comparisons, in other European countries in the setting of post-myocardial infarction.
Tissue Factor Expression and Metastatic Potential of Colorectal Cancer
Authors: Wada Hideo , Matsumoto Kouichi , Shiku Hiroshi , Nakamura Shin , Suzuki Hiroshi , Shigemori Chika
Published: March 2018

Several studies have previously demonstrated tissue factor (TF) expression in solid tumors. In our study, we evaluated by immunohistochemical staining TF expression in 79 cases of colorectal cancer and 17 cases of metastatic cancer of the liver from colorectal cancer, and investigated the relationship between the clinicopathological features and TF expression.

TF was detected in the tumor of 57% of colorectal cancer patients, and its expression was significantly increased (p = 0.01) in metastatic tumors (88%). TF expression was more commonly observed in meta-static tumors than in any Dukes’ stage of primary cancer. In primary cancer, the detection of TF was more frequent in cases with lymph node metastasis (Dukes’ C, 63%) or with hematogenous metastasis (Dukes’ D, 82%) than in tumors without lymph node or hematogenous metastasis (Dukes’ A and B, 46%, p = 0.03).

These results suggest that the expression of TF is related with the metastatic potential of colorectal cancer.
Evidence for the Expression of Urokinase-type Plasminogen Activator by Human Venous Endothelial Cells In Vivo
Authors: Camoin L. , Pannell R. , Anfosso F. , Lefevre J. P. , Sampol J. , Dignat-George F. , Gurewich V.
Published: March 2018

Endothelial cells (ECs) in culture synthesize and secrete urokinase-type plasminogen activator (u-PA), but the normal vascular endothelium is believed to synthesize only tissue plasminogen activator (t-PA), which is thought to be responsible for intravascular fibrinolysis. More recently, animal studies have shown that the biological role of u-PA in fibrinolysis has been underestimated, prompting a re-examination of its synthesis by the endothelium. In this study, we investigated whether u-PA was synthesized by non-atherosclerotic endothelial cells in vivo by testing ECs dislodged by venipuncture from 12 normal volunteers and 17 patients admitted for plasmapheresis. The ECs were isolated with an anti-endothelial monoclonal antibody coupled to immunomagnetic beads and characterized by morphology and by labelling for vWF, CD31, and UEA-1 binding. U-PA antigen was found in 50% of the ECs from the normal subjects and in 60% of those from patients. U-PA enzymatic activity on zymograms was detected in 50% of the normal samples and 60% of the patient samples, with the latter being more frequently and more strongly positive. U-PA mRNA was found in all the normal and patient samples tested. The results indicate that u-PA is synthesized by the venous endothelium in vivo but that its expression is highly variable.
von Willebrand Factor (vWf) as a Plasma Marker of Endothelial Activation in Diabetes: Improved Reliability with Parallel Determination of the vWf Propeptide (vWf:AgII)
Authors: Emeis Jef , Bilo Henk , Stehouwer Coen , Thomsen Claus , Rasmussen Ole , Hermansen Kjeld , Wollheim Claes , Ingerslev Jørgen , Vischer Ulrich
Published: March 2018

Elevated plasma von Willebrand factor (vWf) levels are found in diabetes and other vasculopathies, and predict cardiovascular mortality. vWf is stored and released from endothelial cell secretory granules, along with equimolar amounts of its propeptide (vWf:AgII). In the present study, we examined plasma propeptide levels as a marker of endothelial secretion in vivo, using an ELISA based on monoclonal antibodies. vWf but not propeptide levels are influenced by blood groups, explaining in part the smaller variation in plasma propeptide levels among normal individuals. In both controls and insulin-dependent diabetic patients, we found a close correlation between propeptide and immunoreactive vWf levels (r2 = 0.54, p <0.0001). vWf and propeptide were elevated in patient subgroups with microalbuminuria or overt diabetic nephropathy, whereas only the propeptide was significantly elevated in the normoalbuminuric subgroup. This observation suggests that in conjunction with vWf, propeptide measurements may improve the identification of endothelial activation, which occurs frequently even without increased urinary albumin excretion. In 12 NIDDM patients, a 3-week diet enriched in monounsaturated fat (MUFA) resulted in parallel decreases in vWf (-22%, p <0.05) and propeptide (-17%, p <0.05) levels, indicating that the experimental diet affected endothelial secretion rather than vWf catabolism. A carbohydrate-enriched control diet did not significantly influence either marker.

Our results suggest that concomittant determinations of plasma vWf and propeptide are useful tools to assess endothelial activation in vivo, and reinforce our previous conclusion that a diet rich in MUFA can improve endothelial function in NIDDM.
Mutation Profiling in Haemophilia A
Authors: Oldenburg J.
Published: March 2018

Haemophilia A is a X-linked recessive bleeding disorder caused by deficiency or absence of coagulation factor VIII (FVIII) due to heterogeneous defects in the FVIII gene. The large size of the FVIII gene (26 exons spanning 186 kb) has hampered mutation analysis for many years. In 1991 the first systematic analysis of the complete coding region of the FVIII gene was performed by Higuchi et al. using Denaturing Gradient Gel Electrophoresis (DGGE) as a mutation screening method (1, 2). Notably, the causative mutation was not found in about half of the severely affected patients (1). This mystery was solved in 1993, when the intron 22 inversion was discovered (3, 4) that accounts for about 50% of the severe haemophilia A cases. The inversion mutation can be easily detected by Southern Blot. A recently described PCR-based method is more sophisticated, however once established, it allows rapid and convenient detection of the intron 22 inversion (5).
Measurement of Activated Protein C Resistance during Menstrual Cycle in Women with and without the Leiden Mutation
Authors: Bremme K. , Blombäck M. , Wramsby M. L.
Published: March 2018

Variations in the APC ratio during the menstrual cycle were assessed in 25 women without the Leiden mutation, and 10 women who were carrier of the mutation. Blood samples were collected at four occasions during one menstrual cycle. APC ratios were measured with two APTT based plasma methods with and without factor V depleted plasma.

None of the methods were able to accurately discriminate between mutated and non mutated women in all samples. Although a normalized method with factor V depleted plasma was favorable.

The levels of estradiol and progesterone did not differ between mutated and non mutated women.

Our findings suggest that the level of estradiol at estimated time of ovulation is of importance for the response to APC during luteal phase, since the women exhibiting the highest levels of estradiol at time for ovulation had the lowest response to APC.
N-acetyl-cysteine Reduces Neointimal Thickening and Procoagulant Activity after Balloon-induced Injury in Abdominal Aortae of New Zealand White Rabbits
Authors: Eisenberg Paul , Martelli Antonietta , Orsi Patrizia , Sini Daniela , Spallarossa Paolo , Ghigliotti Giorgio , Mereto Eugenio
Published: March 2018

Background: Procoagulant activity and oxidative stress generated by balloon injury to normal vessels promote the migration of medial smooth muscle cells and their proliferation in the intima. We hypothesised that administering levo N-acetyl-cysteine (NAC) i.v. at the time of injury, and s.c. before and after injury would reduce neointimal formation 4 weeks later and would regulate procoagulant activity in vessels with neointima undergoing ballooning a second time. Methods and Results: at the time of injury rabbits received: NAC, unfractionated heparin (HEP) or both (NAC + HEP). Neointimal thickening at 28 days, calculated as the ratio between the intimal and medial area, was attenuated after NAC, HEP and NAC+HEP by 39%, 30% and 47% respectively when compared to untreated injured animals (CONTROLS) (p 0.05). At 28 days, bound thrombin activity and platelet adhesion 1 h after a repeated balloon injury decreased in animals receiving NAC, HEP and NAC+HEP by 54%, 63% and 64% for thrombin activity (p 0.05 vs CONTROLS), and by 56%, 66% and 75% respectively for 111Indium-platelet deposition (p 0.05 vs CONTROLS). Conclusions: NAC in-vivo was effective in reducing neointimal thickening and procoagulant response after balloon injury.
Thrombin Induces the Release of Angiopoietin-1 from Platelets
Authors: Li Jian-Jun , Huang Yao-Qi , Basch Ross , Karpatkin Simon
Published: March 2018

Blood platelets contain angiopoietin-1, a growth factor essential for blood vessel development via stabilization of proliferating endothelial cells. It has recently been reported that angiopoietin-1 can act as a vascular stability factor (Nature Medicine 6:460, 2000). In investigating the normal tissue distribution of angiopoietin-1 from surgically-removed frozen specimens by RT-PCR, we found it consistently present in platelets and megakaryocytes, usually absent in relatively non-vascular tissue: breast, colon, lung, skin, kidney, thyroid, testicle, cervix and occasionally present in tissue enriched with vasculature: prostate, endometrium, ovary, under conditions in which mRNA stability was verified by the positive detection of internal control, actin mRNA. The consistent distribution in platelets and relatively absent distribution in non-vascular normal tissue suggested that the well-known role of platelets in maintaining vascular stability, may in part be due to platelet release of angiopoietin-1 following platelet activation. In this communication we report the incidence of Ang-1 in various normal tissues and demonstrate that thrombin-treated human platelets release angiopoietin-1 in vitro.