bluuebunny/crossref_metadata_2025 huggingface dataset:
Prothrombotic Genotypes Are not Associated with Pre-eclampsia and Gestational Hypertension: Results from a Large Population-based Study and Systematic Review
Authors: Morrison E. R. , Campbell D. M. , Haites N. E. , Wilson B. J. , Watson M. S. , Greaves M. , Vickers M. A. , Miedzybrodzka Z. H.
Published: March 2018

DNA samples collected as part of a large population-based casecontrol study were genotyped to examine the associations of five prothrombotic gene polymorphisms with pre-eclampsia (PE) and gestational hypertension (GH). The polymorphisms studied were: G1691A in Factor V (Factor V Leiden; FVL), prothrombin G20210A, methylenetetrahydrofolate reductase (MTHFR) C677T, plasminogen activator inhibitor-1 4G/5G and the platelet collagen receptor α2β1 C807T. A group of 404 women who developed PE were retrospectively compared with 303 women with GH and 164 control women. The frequency of genotypes did not differ significantly between cases of PE or GH and controls for any of the five polymorphisms studied. We conclude that these prothrombotic genotypes are not associated with the development of PE or GH in our population. The systematic review supports our conclusion, for all but cases of severe disease, which appear to be associated with FVL and, to a lesser extent, MTHFR C677T. There is little value in antenatal screening for prothrombotic polymorphisms to predict the development of pre-eclampsia or gestational hypertension.
Increased Superoxide Anion Production by Platelets in Hypercholesterolemic Patients
Authors: Sanguigni Valerio , Pignatelli Pasquale , Caccese Daniela , Pulcinelli Fabio , Lenti Luisa , Magnaterra Roberta , Martini Francesca , Lauro Renato , Violi Francesco
Published: March 2018

The purpose of this study was to investigate the relationship between hypercholesterolemia and superoxide anion production.

Experimental studies demonstrated that hypercholesterolemia is associated with enhanced cellular superoxide anion (O2
−) production. Aim of the study was to assess whether the same phenomenon occurs in humans.

Lipid profile and platelet O2
− production were measured in 28 patients with hypercholesterolemia, compared with 25 age- and sexmatched healthy subjects, and in 21 out of the 28 patients after 8-week treatment with 10 mg/day atorvastatin (a HMGCoA reductase inhibitor). In order to assess the mechanism by which LDL cholesterol interferes with platelet production of O2
−, human platelets were incubated with LDL cholesterol in the presence of either an inhibitor of the phospholipaseA2 enzyme, AACOCF3, or an inhibitor of NADH/NADPH oxidases, DPI.

O2
− platelet generation was significantly higher (p <0.001) and significantly related to LDL cholesterol (p < 0.001 ) in patients as compared to controls. 8-week treatment with 10 mg/day atorvastatin significantly reduced both LDL cholesterol and O2
− platelet production. This effect was partially related to the cholesterol-lowering, in that three days of treatment with atorvastatin significantly decreased platelet O2
− production, while no significant change in LDL-cholesterol levels was observed. Platelets incubated with LDL cholesterol showed O2
− release by atorvastatin is partially related to cholesterol lowering effect, suggesting that other mechanisms could be responsible for the antioxidant activity of the drug.
Fibrinogen Predicts Restenosis after Endovascular Treatment of the Iliac Arteries
Authors: Exner Markus , Mlekusch Wolfgang , Rumpold Helmut , Ahmadi Ramazanali , Sabeti Schila , Wagner Oswald , Minar Erich , Schillinger Martin
Published: March 2018

Fibrinogen is an acute phase protein as well as a component of the coagulation cascade. Vascular inflammation and disturbed coagulation are suggested to cause restenosis after percutaneous transluminal angioplasty (PTA). We investigated the prognostic impact of fibrinogen on restenosis after endovascular treatment of iliac artery occlusive disease.

In a prospective cohort study 137 consecutive patients after iliac artery PTA (n = 74) and PTA plus selective stent implantation (n = 63) were included, 109 patients after lower limb angiography served as a control group. Patients were followed for 6 months with oscillography, ankle brachial index and duplex sonography for occurrence of restenosis. Fibrinogen and serum amyloid A (SAA), as a control parameter of inflammation, were obtained at baseline, 8, 24 and 48 h postintervention.

PTA (adjusted OR 3.1, p = 0.05) and stenting (adjusted OR 13.3, p = 0.001) were independently associated with a higher postintervention increase of fibrinogen compared to angiography. Restenosis was found in 29 patients (21%). Patients with pre-intervention fibrinogen values in the third quartile (411-463 mg/dl) had a 6.2-fold increased adjusted risk for restenosis (p = 0.03), patients in the fourth quartile (> 463 mg/dl) had a 8.9-fold increased adjusted risk (p = 0.007). Pre-intervention SAA values were also significantly associated with restenosis (p < 0.0001). Postintervention fibrinogen and SAA levels showed no association with outcome.

Balloon angioplasty and stenting of the iliac arteries cause an elevation of postintervention fibrinogen levels independently of angiographic factors. A higher pre-procedure fibrinogen level, presumably a marker of inflammatory activity, indicates a higher risk for restenosis.
FAK-mediated Inhibition of Vascular Smooth Muscle Cell Migration by the Tetraspanin CD9
Authors: Scherberich Arnaud , Giannone Grégory , Perennou Elisabeth , Takeda Kenneth , Boucheix Claude , Rubinstein Eric , Lanza François , Beretz Alain
Published: March 2018

Migration of vascular smooth muscle cells (SMC) towards the intima is a key event in vascular proliferative diseases. We investigated a potential role for the tetraspanin CD9 in this process in a wound migration assay. Aortic SMC from CD9 knock-out mice had higher migration rates and the presumably stimulatory anti-CD9 antibody ALMA-1 inhibited migration of human SMC. The signaling pathways responsible for this inhibitory effect were investigated. In migrating CD9−/− SMC, stress fiber formation was decreased and focal adhesions were smaller and more diffusely distributed, consistent with an inhibition of integrin clustering. In migrating mouse SMC expressing CD9, focal adhesion kinase (FAK) tyrosine phosphorylation was doubled. No differences in intracellular calcium signaling were observed between CD9+/+ and CD9−/− SMC during migration. We suggest that CD9 inhibits SMC migration by a stimulation of both stress fiber formation and integrin clustering, leading to a stimulation of FAK phosphorylation.
Factor VIIa Induced Release of von Willebrand Factor from Human Umbilical Vein Endothelial Cells by a Tyrosine Kinase Dependent Pathway
Authors: Bowen Derrick , Hallett Maurice , Giddings John , Collins Peter , Brown Simon
Published: March 2018

The interaction of FVIIa with surface-bound tissue factor (TF) induces various cellular changes including cytosolic Ca2+ signals. The release of von Willebrand factor (VWF) from endothelial cell stores may be triggered by an elevation in cytosolic free Ca2+, therefore we investigated the effect of rFVIIa on the release of VWF from human umbilical vein endothelial cells (HUVEC). We show here that rFVIIa induces the release of VWF from HUVEC with or without prestimulation with lipopolysaccharide (LPS). The effect of rFVIIa was dose dependent. However, the release of VWF by HUVEC in response to rFVIIa was significantly greater with LPS prestimulation (3.18 times control) than without LPS prestimulation (1.45 times control) (p <0.001). Cytosolic Ca2+ signals were detectable only after LPS prestimulation of HUVEC and these were small compared to those elicited by thrombin. No effect on rFVIIa induced release of VWF was seen in the presence of hirudin, site inactivated rFVIIa or the protein kinase C (PKC) inhibitor staurosporine. However, a tyrosine kinase inhibitor genistein, inhibited the rFVIIa induced release of VWF. These data show that release of VWF can occur without involvement of the cytosolic Ca2+/ PKC pathway. FVIIa induced VWF release from endothelial cells may have in vivo significance at sites of TF expression.
Molecular evolution of the vertebrate blood coagulation network
Authors: Davidson Colin , Hirt Robert , Lal Kalpana , Snell Philip , Elgar Greg , Tuddenham Edward , McVey John
Published: March 2018

In mammalian blood coagulation 5 proteases, factor VII (FVII), factor IX (FIX), factor X (FX), protein C (PC) and prothrombin act with two cofactors factor V and factor VIII to control the generation of fibrin. Biochemical evidence and molecular cloning data have previously indicated that blood coagulation involving tissue factor, prothrombin and fibrinogen is present in all vertebrates. Using degenerate RT-PCR we have isolated and characterized novel cDNAs with sequence identity to the blood coagulation serine proteases and cofactors from chicken and the puffer fish (Fugu rubripes). Sequence alignments, phylogenetic and comparative sequence analysis all support the existence of the Gla-EGF1-EGF2-SP domain serine proteases FVII, FIX, FX, PC and the A1-A2-B-A3-C1-C2 domain protein cofactors FV and FVIII in these species. These results strongly suggest that the blood coagulation network is present in all jawed vertebrates and evolved before the divergence of tetrapods and teleosts over 430 million years ago; and that vertebrate blood coagulation may have benefited from two rounds of gene or whole genome duplication. Sequences identified in Fugu coding for additional FVII-like, FIX-like and PC-like sequences support the possibility of further tandem and large-scale duplications in teleosts. Comparative sequence analyses of amino acid residues in the active site region suggest these additional sequences have evolved new and as yet unknown functions.

Supplementary information to this article available at both http://europium.csc.mrc.ac.uk and www.thrombosis-online.com
Viral hemorrhagic fever – a vascular disease?
Authors: Feldmann Heinz , Schnittler Hans
Published: March 2018

The syndrome of “viral hemorrhagic fever” in man caused by certain viruses, such as Ebola, Lassa, Dengue, and Crimean-Congo hemorrhagic fever viruses, is often associated with a shock syndrome of undetermined pathogenesis. However, the vascular system, particularly the vascular endothelium, seems to be directly and indirectly targeted by all these viruses. Here we briefly summarize the current knowledge on Marburg and Ebola virus infections, the prototype viral hemorrhagic fever agents, and formulate a working hypothesis for the pathogenesis of viral hemorrhagic fever. Infections with filoviruses show lethality up to 89% and in severe cases lead to a shock syndrome associated with hypotension, coagulation disorders and an imbalance of fluid distribution between the intravascular and extravascular tissue space. The primary target cells for filovi-ruses are mononuclear phagocytotic cells which are activated upon infection and release certain cytokines and chemokines. These mediators indirectly target the endothelium and are thought to play a key role in the pathogenesis of filoviral hemorrhagic fever. In addition, direct infection and subsequent destruction of endothelial cells might contribute to the pathogenesis. Filoviruses, particularly Ebola virus, encode nonstructural glycoproteins which are released from infected host cells. Their function as potential determinants in pathogenicity remains to be investigated.
Protofibrils within fibrin fibres are packed together in a regular array
Authors: Caracciolo Giulio , De Spirito Marco , Castellano Agostina , Pozzi Daniela , De Pascalis Angela , Caminiti Ruggero , Arcovito Giuseppe , Amiconi Gino
Published: March 2018

The inner structure of fibrin fibres grown from fibrinogen solution activated by human α-thrombin was investigated by means of an Energy Dispersive X-ray Diffraction technique. The experiments show evidence for the well-characterized 22.5 nm repeat distance, which indicates the high order of protofibril arrangement in the longitudinal direction of fibres. The diffraction pattern also manifested a further pronounced peak at 18.1 nm (and its second order reflection at 18.1/√2) demonstrating the existence in fibrin of a high degree of lateral order. The reported results directly confirm, on unperturbed wet samples, that protofibrils closely associate giving rise to a crystalline axial and equatorial packing according to the conclusions of the multibundle model.

Theme paper: Part of this work was originally presented at the joint meetings of the 16th International Congress of the International Society of Fibrinolysis and Proteolysis (ISFP) and the 17th International Fibrinogen Workshop of the International Fibrinogen Research Society (IFRS) held in Munich, Germany, September, 2002.
Low-molecular-weight heparin in the acute and long-term treatment of deep vein thrombosis
Authors: Gebska Milena , Kadziola Zbigniew , Saba Neelam , Carrasco Pilar , Kakkar Vijay ,   on behalf of the Bemiparin Investigators
Published: March 2018

Low molecular weight heparins (LMWHs) are frequently used during acute treatment of deep vein thrombosis, but their utility for long-term treatment needs to be defined.

In this multi-centre trial, 378 patients with acute deep vein thrombosis were randomised to intravenous unfractionated heparin (group A), once daily subcutaneous LMWH (bemiparin) for one week (group B) or once daily bemiparin in a therapeutic dose for one week followed by a maintenance dose for 12 weeks (group C).

Fifty-two per cent of patients in group A, 72% of group B and 72% of group C showed venographic reduction in thrombus size assessed objectively on day 14; 20% greater improvement in group B and C indicates not only non-inferiority of bemiparin (p = 0.00003) but also superiority (p = 0.004) compared to UFH. Day 84 venographic or Doppler sonographic recanalisation of the affected veins was demonstrated in 75.3%, 79.8% and 81.5% in groups A, B and C respectively. Mortality, recurrent thromboembolic events and bleeding were similar in the three groups.

Both bemiparin regimens were more effective than UFH in reducing thrombus size during the acute phase of treatment. The efficacy in terms of recurrence of venous thromboembolism and safety of Bemiparin is similar to UFH. Bemiparin is also an effective alternative to warfarin for long-term treatment.
Exclusion of Deep Venous Thrombosis with D-Dimer Testing
Authors: van den Borne Henk , van der Kolk Marion , de Wild Piet , Janssen Ger , van Uum Stan , van der Graaf Fedde
Published: March 2018

In a direct assay comparison we evaluated the diagnostic performance of 10 novel D-Dimer assays for the exclusion of deep venous thrombosis (DVT). In addition, 3 conventional ELISA D-Dimer assays were included as reference tests. The study was performed in 99 consecutive outpatients referred to the emergency department for clinical suspicion of DVT. Venography was used as reference standard and demonstrated the presence of DVT in 50 patients (6 patients with isolated distal DVT and 44 patients with proximal DVT). The qualitative D-Dimer assays Minutex and SimpliRED and the quantitative BC DD showed overall sensitivities (for proximal and distal DVT) of only 80-83% with specificities that ranged from 87 to 94%. Overall sensitivity was 94% for the qualitative INSTANT I.A. and 98% for the quantitative Turbiquant at a cut-off level equal to the detection limit. Using different cut-off levels a sensitivity of 100% for proximal DVT and for proximal as well as distal DVT could be obtained for NycoCard, IL DD, Liatest, Tinaquant and VIDAS D-Dimer assays with specificities that ranged from 31% (NycoCard) to 71% (VIDAS) for proximal DVT and from 12% (NycoCard) to 47% (IL DD) for overall DVT. At a cut-off level equal to the upper limit of the reference range only Tinaquant and VIDAS showed a sensitivity of 100% for proximal as well as for distal DVT with a specificity of 39% and 41% respectively.

The results of this study suggest that the VIDAS and Tinaquant D-Dimer assays have the highest sensitivity for the exclusion of DVT in outpatients. In outpatients that have a low or moderate pretest probability for DVT, these tests may be used in management studies where anticoagulation is withheld on the basis of D-Dimer testing alone.
A Simple, Quick One-step ELISA Assay for the Determination of Complex Plasma Factor XIII (A2B2)
Authors: Katona Éva , Haramura Gizella , Kárpáti Levente , Fachet József , Muszbek László
Published: March 2018

A new highly sensitive sandwich ELISA assay was developed for the determination of plasma factor XIII (FXIII). Plasma FXIII is a tetrameric complex of two types of subunits (A2B2). A biotinylated monoclonal capture-antibody against the B-subunit and a peroxidase-labelled monoclonal tag-antibody against the A-subunit were added to the plasma dilution and the amount of the complex attached to streptavidincoated microplate was quantitated by measuring peroxidase activity. Only the tetrameric plasma FXIII reacted in the assay, non-complexed A or B subunits showed no reaction. The assay is linear up-to 40 µg/L of FXIII in the assay mixture. It is a quick one-step assay which can be performed within two hours. At normal and low FXIII concentration within batch reproducibility was 2.0% and 3.3%, day to day variation was 5.5% and 8.7%, respectively. Its high sensitivity allows reliable measurement at FXIII concentrations below 1% of normal average. Plasma samples can be stored for the assay at –20° C for at least one month. Plasma levels of healthy individuals were normally distributed and no gender difference was observed. A reference interval of 14-28 mg/L (67-133%) was established.
Lack of tPA Significantly Affects Antithrombotic Therapy by a GPIIb/IIIa Antagonist, but not by a Thrombin Inhibitor in Mice
Authors: Kozawa Osamu , Ueshima Shigeru , Matsuo Osamu , Collen Désiré , Uematsu Toshihiko , Matsuno Hiroyuki
Published: March 2018

The interaction of fibrinolytic components with platelets or coagulation factors after endothelial injury, was investigated in mouse deficient in tissue type plasminogen activator (tPA –/–), or urokinase (uPA –/–) and in their wild type control (tPA +/+, uPA +/+). A thrombus was induced in the murine carotid artery using the photochemical reaction. Blood flow was continuously monitored and the time needed before the vessel became completely obstructed was within 11 min in all types of mice. When GR144053, a platelet glycoprotein IIb/IIIa antagonist, or argatroban, a thrombin inhibitor, was applied, the time required to occlusion was prolonged in a dose-dependent manner in all types of mice. However, when GR144053 was injected in tPA –/– mice, the most significant changes were observed: that is the estimated ED50 was 14.8 times higher than the one in tPA +/+ mice. On the other hand, when argatroban was injected in tPA –/– mice, the estimated ED50 was not changed. Platelet aggregation, haemostasis tests and bleeding times were not significantly different among the different types of mice. In conclusion, the antithrombotic effect of platelet inhibition by a GPIIb/IIIa antagonist, is severely affected by the absence or presence of tPA-production. Thus, the lack of tPA significantly reduces the antithrombotic efficacy.
Intimal Tissue Factor Activity Is Released from the Arterial Wall after Injury
Authors: Giesen Peter , Fyfe Billie , Fallon John , Roque Merce , Mendlowitz Milton , Rossikhina Maria , Guha Arabinda , Badimon Juan , Nemerson Yale , Taubman Mark
Published: March 2018

Tissue factor (TF), the initiator of coagulation, has been implicated as a critical mediator of arterial thrombosis. Previous studies have demonstrated that TF is rapidly induced in the normal rodent arterial wall by balloon injury, but is not associated with fibrin deposition. A second injury, however, performed 10–14 days after the first, is followed by small platelet-fibrin microthrombi. This study was undertaken to better localize active TF in balloon-injured rat arteries and to explore possible mechanisms underlying the apparent discrepancy between injury-induced TF expression and the lack of large platelet-fibrin thrombi. By immunohistochemistry, TF antigen was first detected in the media 24 h after injury to rat aortas, and subsequently accumulated in the neointima. Using an ex vivo flow chamber, no TF activity (Factor Xa generation) was found on the luminal surface of normal or injured aortas. Wiping the luminal surface with a cotton swab exposed TF activity in all vessels; levels were increased ≈3-fold in arteries containing a neointima. The exposed TF activity was rapidly washed into the perfusate, rendering the luminal surface inactive. The loss of luminal TF into the circulation may attenuate thrombosis at sites of arterial injury.
The Rsal Polymorphism in the α-Fibrinogen Gene and Response of Plasma Fibrinogen to Physical Training
Authors: Väisänen Sari , Kuhanen Raimo , Penttilä Ilkka , Bouchard Claude , Rauramaa Rainer
Published: March 2018

We have previously reported cross-sectional data on an interaction effect between physical activity and α-fibrinogen Rsal polymorphism on fibrinogen in postmenopausal women. In the present controlled randomised study, we investigated the role of the Rsal polymorphism in determining the response of fibrinogen to long-term regular exercise. Middle-aged men (n = 140), randomly selected from the population registry, were randomised into an exercise or a reference group for a 3-year low intensity exercise intervention. Complete data were available in 125 men. The Rsal restriction enzyme detects threonine (Thr) to alanine change in the fibrinogen α codon 312. Anaerobic ventilatory threshold increased by 4%, but decreased by 2% in the exercise and reference groups, respectively. Mean fibrinogen did not decrease in either study group. However, in the exercise group, individual changes in anaerobic threshold explained 48% of the variance in fibrinogen changes in the Thr homozygotes. Our data offer a new aspect of beneficial effects of regular physical exercise on risk factors for coronary heart disease.
Prothrombotic Risk Factors in Children with Acute Lymphoblastic Leukemia Treated with Delayed E. coli Asparaginase (COALL-92 and 97 Protocols)
Authors: Mauz-Körholz Christine , Junker Ralf , Göbel Ulrich , Nowak-Göttl Ulrike
Published: March 2018

Hereditary prothrombotic risk factors have been shown to increase the risk of venous thrombosis in children treated with the combination of E. coli asparaginase and steroids. In the present study the role of prothrombotic risk factors in children with ALL treated according to the COALL study protocol was investigated in 108 consecutively recruited childhood patients. The prevalence rates of prothrombotic risk factors [factor V G1691A mutation, the prothrombin G20210A variant, the TT677 methylenetetrahydrofolate reductase genotype, deficiencies of protein C, protein S, antithrombin, elevated lipoprotein (a)] in this cohort were within the range reported for healthy Caucasians, and comparable to previously reported data for other leukemic patients. Venous thromboembolism occurred in 3 of the 108 children (induction n = 1; reinduction n = 2: 2.8%), and none of these children carried a prothrombotic risk factor. The results of the present study, suggest that the role of hereditary and acquired disturbances of coagulation in the development of thromboses might depend on the treatment regimen.
Prevention of Renal Fibrin Deposition in Endotoxin-induced DIC through Inhibition of PAI-1
Authors: Montes Ramón , Declerck Paul , Calvo Alfonso , Montes Marta , Hermida José , Muñoz María , Rocha Eduardo
Published: March 2018

Plasminogen activator inhibitor-1 (PAI-1) increases in endotoxemia thus possibly cooperating in altering the hemostatic balance in a prothrombotic direction. The effect of the inhibition of PAI-1 with the monoclonal antibody MA-33B8 was studied systemically and in kidneys in a lapine model of endotoxin-induced disseminated intravascular coagulation (DIC). The increase in plasmatic PAI activity in the control group (n = 9) was inhibited in the MA-33B8 treated rabbits (n = 5). Control rabbits showed renal fibrin deposits, whereas only one of the MA-33B8 rabbits did so. These results were confirmed immunohistochemically in kidneys as PAI-1 immunostaining was seen inside the glomeruli and larger vessels in the control group, whereas MA-33B8 rabbits showed a remarkable decrease, demonstrating that MA-33B8 successfully inhibited PAI-1 in the kidneys as well. Therefore evidence for the important role of PAI-1 in fibrin generation in endotoxin-induced DIC is presented, suggesting that strategies aiming at its reduction can be useful in this pathology.
Type 2M vWD Resulting from a Lysine Deletion within a Four Lysine Residue Repeat in the A1 Loop of von Willebrand Factor
Authors: Jenkins P. V. , Gaucher C. , Meriane E. , Collins P. W. , Pasi K. J. , Mazurier C. , Hilbert L.
Published: March 2018

Type 1 von Willebrand disease is characterized by a decreased plasma concentration of functionally normal von Willebrand factor (vWF) whereas type 2M is characterised by an abnormal vWF displaying decreased affinity for platelets. In these two types of patients, the multimeric structure of vWF is normal.

We report here the identification, in two unrelated families from the UK and Algeria, of an in-frame 3 bp deletion, at the heterozygous state, resulting in the deletion of a lysine residue within a four lysine repeat at position 642-645 of the mature vWF subunit (del K1405-1408 in prepro vWF). The patients who have a discrepancy between vWF antigen level and vWF ristocetin cofactor activity exhibited decreased ristocetin-induced binding but only a slight decrease in the percentage of high molecular weight (HMW) multimers in plasma.

Recombinant vWF harbouring this deletion did not bind to platelet GPIb in the presence of ristocetin or botrocetin although the protein is multimerized. Consequently, this lysine deletion was considered as a type 2M vWD mutation.
Acute Exacerbations of Chronic Obstructive Pulmonary Disease Are Accompanied by Elevations of Plasma Fibrinogen and Serum IL-6 Levels
Authors: Seemungal Terence , MacCallum Peter , Paul Elizabeth , Donaldson Gavin , Bhowmik Angshu , Jeffries Donald , Meade Thomas , Wedzicha Jadwiga
Published: March 2018

Respiratory tract infections may acutely increase risk from coronary heart disease (CHD), though the mechanisms have not been defined. Patients with chronic obstructive pulmonary disease (COPD) are prone to repeated exacerbations that are often associated with respiratory infections. These patients also have increased cardiovascular morbidity and mortality. We hypothesized that transient acute increases in plasma fibrinogen, an independent risk factor for CHD, could occur at COPD exacerbation (mediated through a rise in IL6) and thereby provide a mechanism linking respiratory infection to risk of coronary heart disease.

93 COPD patients [mean (SD) age 66.8 (8.1) years] were followed regularly over one year, with daily diary card monitoring of respiratory symptoms and peak expiratory flow rate (PEFR); 67 patients [mean FEV1 1.06 (0.44) l, FVC 2.43 (0.79) l] were seen during 120 exacerbations. At each visit spirometry was measured and blood samples taken for plasma fibrinogen and Interleukin-6 (IL-6) levels.

At baseline, the mean (SD) plasma fibrinogen was elevated at 3.9 (0.67) g/l in the 67 patients with exacerbations during the study and the median (IQR) IL-6 at 4.3 (2.4 to 6.8) pg/ml. Plasma fibrinogen increased by 0.36 (0.74) g/l at exacerbation (p <0.001), with IL-6 levels rising by 1.10 (−2.73 to 6.95) pg/ml (p = 0.008). There was a relation between the changes in fibrinogen at exacerbation and IL-6 levels (r = 0.348, p <0.001). Multiple regression revealed significantly greater rises in fibrinogen when exacerbations were associated with purulent sputum (b = 0.34 g/l; p = 0.03), increased cough (b = 0.31 g/l, p = 0.019) and symptomatic colds (b = 0.228; p = 0.024).

Plasma fibrinogen levels were elevated in stable patients with COPD and may contribute to the increased cardiovascular morbidity and mortality in these patients. COPD exacerbations increased serum IL-6 levels, leading to a rise in plasma fibrinogen. Thus acute rather than chronic infection may have a role in predisposing to coronary heart disease or stroke.
Fluid Shear Stress Increases the Intra-cellular Storage Pool of Tissue-type Plasminogen Activator in Intact Human Conduit Vessels
Authors: Sjögren Lena , Gan Liming , Doroudi Roya , Jern Christina , Jungersten Lennart , Jern Sverker
Published: March 2018

We investigated the effect of shear stress on the expression of tissuetype plasminogen activator (t-PA) in intact human conduit vessels. Human umbilical veins were exposed to high or low shear stress (25 vs < 4 dyn/cm2) at identical intraluminal pressure (20 mmHg) for 1.5, 3, and 6 h in a new computerized biomechanical perfusion system. High shear perfusion induced a marked, time-dependent increase in t-PA immunostaining in both the endothelium and the media. t-PA relative to GAPDH gene expression increased by 54 ± 14% in highcompared to low-sheared vessels (p = 0.002). By contrast, t-PA release into the perfusion medium was similar in vessels perfused under high or low shear stress conditions. The results show that shear stress independently of pressure is a potent fluid mechanical stimulus for upregulation of the intracellular storage pool of t-PA in the vascular wall of fresh human conduit vessels. The shear effect is associated with an increased t-PA gene expression.
Assay of Functional Plasminogen in Rat Plasma Applicable to Experimental Studies of Thrombolysis
Authors: Bangert Kristian , Thorsen Sixtus
Published: March 2018

An improved sensitive, specific, precise and accurate assay of plasminogen in rat plasma was developed. It is performed in 96-well microtiter plates and can be completed within one hour. The assay is based on activation of plasminogen by human urokinase-type plasminogen activator (uPA) and simultaneous measurement of generated plasmin with the specific plasmin substrate H-D-Val-Phe-Lys-4-nitroanilide (S-2390), using purified native rat plasminogen for calibration. The concentration of S-2390 in the final reaction mixture during the whole reaction period is much greater than the K
m value (≈20 µM) for rat plasmin-cleavage of S-2390 ensuring that hydrolysis of substrate follows zero order kinetics and that the substrate produces a 20-35 fold decrease in rate of inhibition of plasmin by its target inhibitors in plasma. Analogous to the human system the target plasma inhibitors of rat plasmin are shown to be plasmin inhibitor and α-macroglobulins. Tranexamic acid (0.8 mM) is incorporated in the reaction mixture resulting in a 19-fold increase in the rate of plasminogen activation and presumably an about 50-fold decrease in the rate of inhibition of generated plasmin by plasmin inhibitor. The assay is suitable for accurate measurement of plasminogen in samples obtained from animals containing pharmacological concentrations of uPA or tissue-type plasminogen activator (tPA) in their plasma when in vitro plasminogen activation is blocked at pH 5 by collecting blood in acidic anticoagulant. Judged from in vitro experiments formation of catalytic active plasmin-α-macroglobulin complexes during massive activation of plasminogen in vivo does not interfere with the assay.
Pre-Clinical Pharmacological Profile of the Novel Glycoconjugate Org 36764 with both Factor Xa and Thrombin (IIa) Inhibitory Activities
Authors: van Amsterdam Ronald , van Dinther Theo , Tromp Marijke , Meuleman Dirk , Vogel Gerard
Published: March 2018

Org 36764, is an antithrombin III (AT) and thrombin binding carbohydrate, which accelerates the inactivation of both factor Xa and thrombin by AT. It displays in buffer an anti-Xa and anti-thrombin activity of 415 and 2 U/mg, respectively, compared to 172 and 114 U/mg, respectively, for unfractionated heparin (UFH). Org 36764 does not cross-react with HIT (heparin induced thrombocytopenia) antibodies and is not neutralised by PF4. In experimental models in rats, on a molar basis, Org 36764 was more active than the pentasaccharide SanOrg 34006 (= AT binding domain of Org 36764) in arterial thrombosis, but both were equally active in venous thrombosis. In arterial thrombosis following endothelial damage by ferric chloride, Org 36764 was more active than the LMW heparin enoxaparin and SanOrg 34006 and similar active to UFH. At AT saturating doses the bleeding enhancement was not more than 3.5 times the control value. Org 36764 was more active in suppressing in vivo thrombus formation on stents than UFH, SanOrg 34006 or a combination of ticlopidine and aspirin. The results indicate that the novel drug Org 36764 is a drug with antithrombotic potential against venous and arterial thrombosis.
Verotoxin-1 Induces Tissue Factor Expression in Human Umbilical Vein Endothelial Cells through Activation of NF-κB/Rel and AP-1
Authors: Takada Kimihiko , Higuchi Toshiyuki , Sugiyama Junichi , Ishii Hidemi
Published: March 2018

This study examined the effect of verotoxin-1 (VT-1), which is released from Escherichia coli O157:H7, on endothelial expression of tissue factor (TF), a cofactor required to initiate blood coagulation. In order to elucidate the molecular basis for development of hemolytic uremic syndrome (HUS) in patients infected with E. coli O157:H7, human umbilical vein endothelial cells (HUVECs) were exposed to purified VT-1. VT-1 increased both TF activity and TF mRNA in HUVECs without loss of cell viability in a time-and dose-dependent manner from 0.1 to 10 ng/ml VT-1. Nuclear proteins extracted from VT-1-stimulated HUVECs bound to the consensus NF-κB/Rel and AP-1 binding oligonucleotides in a dose-dependent manner within 2 h after the stimulation in electrophoretic mobility shift assays (EMSA). Nuclear proteins from VT-1-stimulated HUVECs formed two complexes with the NF-κB/Rel binding motif in the human TF promoter (TF-κB motif). The supershift assays, using antibodies for human p65, p50 or c-Rel, indicated that the lower complex was composed of p65/p50 and the higher complex was a p65 homo-or hetero-dimer with the Rel family, except c-Rel. The human TF promoter contains two AP-1 binding sites, the proximal and distal AP-1 binding sites. The supershift assays indicated that AP-1 containing mainly c-Jun and JunD, positively bound to the proximal AP-1 motif of TF (TF-AP-1). The distal TF-AP-1 motif did not show positive binding with nuclear proteins from VT-1-stimulated HUVECs. Pretreatment of HUVECs with curcumin, an inhibitor of NF-κB/Rel activation, synthesis of c-Jun mRNA and binding of activated AP-1 with AP-binding oligonucleotide, prevented the VT-1 induced increase in TF mRNA and activity in VT-1-stimulated HUVECs. Curcumin also inhibited NF-κB and AP-1 binding to TF-κB and proximal TF-AP-1 oligonucleotides, respectively, in a dose-dependent manner. The present work suggests that both the NF-κB/Rel and AP-1 activated in endothelial cells by stimulation with VT-1 binds to the TF-κB and proximal AP-1 binding sites, respectively, of the TF promoter.
Heparin-induced Thrombocytopenia: Towards Consensus
Authors: Warkentin Theodore , Chong Beng , Greinacher Andreas
Published: March 2018

Heparin-induced thrombocytopenia (HIT) is a drug-induced, immunoglobulin-mediated thrombocytopenic disorder that is important for at least three reasons. First, it is a relatively common drug-induced immunohematologic adverse reaction. Second, it is frequently complicated by life- and limb-threatening thrombotic complications. And third, there remains uncertainty about the optimal treatment approach for these patients. Recently, there has emerged increasing consensus on such important issues as the frequency, pathogenesis, and diagnostic testing, which we will summarize here. Further, a greater appreciation of the activation of the coagulation pathways in this syndrome indicate a rationale to treatment approaches that emphasize thrombin inhibition (eg. danaparoid sodium; hirudin and its analogues).
Factor V Q506 Mutation (Activated Protein C Resistance) Associated with Reduced Intrapartum Blood Loss – a Possible Evolutionary Selection Mechanism
Authors: Svensson Peter , Dahlbäck Björn , Maršál Karel , Lindqvist Pelle
Published: March 2018

Objectives. To ascertain whether relationship exists between the presence of APC resistance [a hypercoagulable state due to a mutation (R506Q) in the factor V gene] and the occurrence of pre-eclampsia (PE), intrauterine growth retardation (IUGR), and pregnancy bleeding complications. Design. A retrospective study. Subjects. A study group of 122 women with PE and/or IUGR during a recent pregnancy and a control group of 465 healthy pregnant women. Results. A significantly reduced risk of intrapartum bleeding complications in the APC-resistant subgroup as compared to the non-APC-resistant subgroup was suggested by reduced intrapartum blood loss, and pre- and postpartum haemoglobin measurements. The prevalence of APC resistance in the PE and IUGR subgroups did not differ significantly from that in the control group. Conclusion. The remarkably high prevalence of the potentially harmful factor V gene mutation in the general population may be the result of an evolutionary selection mechanism conferring such survival advantages as reduction in the risk of intrapartum bleeding on carriers of the FV:Q506 allele.
Factor XII Determinations in the Presence and Absence of Phospholipid Antibodies
Authors: Jones D. W. , Winter M. , Gallimore M. J.
Published: March 2018

Factor XII (FXII) levels were determined in plasma samples from 29 normal donors, 10 patients with inherited FXII deficiency (all lupus anticoagulant [LA] negative) and 67 LA positive patients, using clotting (FXIIct), chromogenic substrate (FXIIcs) and immunochemical (FXIIag) assays. Excellent correlations were obtained in the three FXII assays with the LA negative samples and between the FXIIcs and FXIIag assays in the LA positive samples. Correlations between both the FXIIcs and FXIIag with FXIIct in the LA positive patients were poor. Of 67 LA positive samples studied, 25 (37.3%) showed lower values in the FXIIct assay; 13 (19.4%) of these patients were pseudo FXII deficient with values of FXII below the lower limit of normal.

These results indicate that a diagnosis of FXII deficiency can be made inappropriately in the presence of phospholipid antibodies and that such a diagnosis should not be made by FXIIct assay alone.
Rapid Detection of D-dimer Using a Fiber Optic Biosensor
Authors: Rowe Chris , Bolitho Jeni , Jane Andrew , Bundesen Peter , Rylatt Dennis , Eisenberg Paul , Ligler Frances
Published: March 2018

We describe a rapid and sensitive method for detection and quantification of D-dimer and other crosslinked fibrin degradation products (XL-FDPs), which are present in elevated concentrations in patients with sepsis and thrombotic disorders. The method utilizes a sandwich fluoroimmunoassay immobilized in the sensing region of an evanescent wave biosensor. Physiological concentrations of D-dimer and high molecular weight XL-FDP could be determined in buffer and plasma samples on calibrated fibers in 11 min. Samples from septic patients were assayed using ELISA and the fiber optic method; concentrations determined by fiber optic assay were strongly correlated with those determined by ELISA (r = 0.918); intra- and inter-assay errors were comparable to those from ELISAs. Given its accuracy and rapid response time, this fiber optic biosensor shows great potential for development as a diagnostic tool.
Platelet Activation and Aggregation Induced by Recombinant von Willebrand Factors Reproducing Four Type 2B von Willebrand Disease Missense Mutations
Authors: Hilbert Lysiane , Mazurier Claudine , de Romeuf Christophe
Published: March 2018

Type 2B of von Willebrand disease (vWD) refers to qualitative variants with increased affinity of von Willebrand factor (vWF) for platelet glycoprotein Ib (GPIb). All the mutations responsible for type 2B vWD have been located in the A1 domain of vWF. In this study, various recombinant von Willebrand factors (rvWF) reproducing four type 2B vWD missense mutations were compared to wild-type rvWF (WT-rvWF) for their spontaneous binding to platelets and their capacity to induce platelet activation and aggregation. Our data show that the multimeric pattern of each mutated rvWF is similar to that of WT-rvWF but the extent of spontaneous binding and the capacity to induce platelet activation and aggregation are more important for the R543Q and V553M mutations than for the L697V and A698V mutations. Both the binding of mutated rvWFs to platelets and platelet aggregation induced by type 2B rvWFs are inhibited by monoclonal anti-GPIb and anti-vWF antibodies, inhibitors of vWF binding to platelets in the presence of ristocetin, as well as by aurin tricarboxylic acid. On the other hand, EDTA and a monoclonal antibody directed against GPIIb/IIIa only inhibit platelet aggregation. Furthermore, the incubation of type 2B rvWFs with platelets, under stirring conditions, results in the decrease in high molecular weight vWF multimers in solution, the extent of which appears correlated with that of plasma vWF from type 2B vWD patients harboring the corresponding missense mutation. This study supports that the binding of different mutated type 2B vWFs onto platelet GPIb induces various degrees of platelet activation and aggregation and thus suggests that the phenotypic heterogeneity of type 2B vWD may be related to the nature and/or location of the causative point mutation.
Outpatient Use of Low Molecular Weight Heparin (Dalteparin) for the Treatment of Deep Vein Thrombosis of the Upper Extremity
Authors: Savage K. J. , Wells P. S. , Schulz V. , Goudie D. , Morrow B. , Cruickshank M. , Kovacs M. J.
Published: March 2018

Upper extremity deep vein thrombosis (DVT) is now recognized as a major cause of morbidity and mortality. There is little information regarding the most effective treatment of this condition. We report a prospective cohort study of the use of low molecular weight heparin (LMWH) in the outpatient management of upper extremity DVT. Forty-six patients were managed as outpatients for objectively documented upper extremity DVT with dalteparin (200 aXa u/kg), for a minimum of five days. Warfarin was usually initiated on the first day with a target INR of 2.0-3.0. Most patients had an underlying malignancy or a history of a central line. All patients were followed for 12 weeks from diagnosis. Only one patient had a major bleed. No patients developed pulmonary emboli. One patient had a recurrence of DVT during the treatment with LMWH with extension of the existing thrombus. Seven patients died, all due to their underlying disease. This study supports the safety and effectiveness of dalteparin in the treatment of upper extremity DVT. Given that these patients were treated as outpatients, there is a potential for huge cost savings.
The Levels of Factor XIIa Generated in Human Plasma on an Electronegative Surface Are Insensitive to Wide Variation in the Concentration of FXII, Prekallikrein, High Molecular Weight Kininogen or FXI
Authors: Mitropoulos K. A.
Published: March 2018

The contribution of the various components of the contact system in the generation of factor XIIa (FXIIa) and of kallikrein (KRN) on an electronegative surface and the release of the generated enzymes to the bulk phase was examined in mixtures of normal human plasma and plasmas congenitally deficient in these components. The incubation of normal human plasma in the presence of sulphatide vesicles (40 μM) resulted in a fast generation of amidolytic activities due to FXIIa and to KRN followed by slower first-order inactivation rates of FXIIa (k’FXIIa) and of KRN (k’KRN) due to the presence of esterase inhibitors. Variation of the levels of factor XII (FXII), over a wide range, showed little effect on levels of FXIIa and of KRN but no activities were detected in 100% FXII-deficient plasma. The variation of prekallikrein (PKRN) concentration showed little effect on the generation of FXIIa but the generation of KRN declined linearly with the decrease in the level of PKRN. No activities were detected on treatment of PKRN-deficient plasma. The variation in the concentration of high molecular weight kininogen (HK) showed effects on FXIIa and KRN that were qualitatively similar to those seen on variation of PKRN but 100% HK-deficient plasma generated considerable activities of both FXIIa and KRN. The variation in the concentration of factor XI (FXI) showed no effect on the generation of FXIIa, whereas KRN levels increased linearly with the contribution of FXI-deficient in normal plasma. The present results suggest that the contiguous binding of FXIIa, FXII, PKRN-HK and FXI-HK onto the electronegative surface induces a rapid generation of FXIIa and KRN. The bound PKRN-HK complex prevents the release of generated FXIIa and therefore further binding and activation of FXII from the bulk phase. Consequently, the turnover of FXII is independent of its levels in the bulk phase and is rather related to the concentration of contact surface. The generated KRN is also protected by HK. However, since the enzyme responsible for the activation of PKRN-HK is FXIIa, the levels of generated KRN are positively related to the concentration of substrate.
Transcriptional Expression of Tissue Factor Pathway Inhibitor, Thrombomodulin and von Willebrand Factor in Normal Human Tissues
Authors: Kuppuswamy M. N. , Manepalli A. N. , Bajaj S. P. , Bajaj M. S.
Published: March 2018

Under normal physiologic conditions, tissue factor pathway inhibitor (TFPI) is synthesized primarily by the microvascular endothelium. Using Northern blotting, we studied its transcriptional expression in different organs and compared it with the expression of two other endothelial specific proteins, namely thrombomodulin (TM) and von Willebrand factor (vWF). The order of mRNA expression for each protein was: TFPI–placenta>lung>liver>kidney>heart>skeletal muscle≥pancreas>brain; TM–heart>pancreas>lung>skeletal muscle>kidney≥liver>placenta>brain; and vWF–heart>skeletal muscle>pancreas>lung≥kidney>placenta>brain>liver. Notably, heart expressed TM and vWF mRNA in large amounts and only small amounts of TFPI whereas lung expressed all three mRNAs in significant amounts. Placenta, on the contrary, expressed large amounts of TFPI but only small amounts of TM and vWF mRNAs. Brain by this technique was found to express undetectable amounts of TFPI and TM mRNAs but small amounts of vWF mRNA. The expression of TFPI mRNA in the brain was however detected by RT/PCR and the antigen was localized to the endothelium of microvessels as well as to the astrocytes and oligodendrocytes. Since ultimate expression of proteins is linked to the expression of their mRNAs, our data support a concept that vascular endothelium is made up of phenotypically diverse groups of cells and that endothelial cells of different vascular beds express specific sets of genes that enable them to carry out tissue-specific functions. Importantly, since astrocytes are known to express tissue factor, the TFPI expression by these cells may control coagulation in their microenvironment and their response to injury and inflammation.