bluuebunny/crossref_metadata_2025 huggingface dataset:
Local versus Central Assessment of Venographies in a Multicenter Trial on the Prevention of Deep Vein Thrombosis in Neurosurgery
Authors: Rossi Romina , Taborelli Piera , Fioroni Claudio , Zerbi Daniela , Pattacini Pietro , Giugni Enrico , Bagatella Paola , Vaccarino Antonella , Agnelli Giancarlo
Published: March 2018

Venography is the diagnostic method of choice for end-point measurement in multicenter trials on the prevention of postoperative deep vein thrombosis (DVT). The aim of the study was to determine the inter-observer agreement between the local and central assessment of venographies in a multicenter trial comparing enoxaparin and placebo in the prevention of DVT after elective neurosurgery.

The study was run in seven centers experienced in venography trials on DVT prevention. The central and local adjudication panels were both blind with respect to the assigned treatment. The central panel was unaware of the local adjudication. Venographies were adjudicated as positive, negative or inadequate for adjudication and positive venographies as proximal or distal DVT. Inter-observer agreement was assessed according to the Cohen’s inter-observer variability index (K index).

All 266 venographies (8 monolateral) were considered adequate for adjudication by both the central and local panels. A disagreement was found in 25 cases; K index = 0.75. Fourteen venographies adjudicated as negative centrally were considered positive locally (3 were proximal DVT). Eleven venographies adjudicated as positive centrally (1 was a proximal DVT) were considered negative locally. Enoxaparin was found to be more effective than placebo according to both the central and local adjudication: 16.9% versus 32.6% (Relative risk, RR = 0.52; CI95% 0.33-0.82) according to central adjudication; 18.5% versus 33.3% (RR = 0.56; CI95% 0.36-0.87) according to local adjudication.

We conclude that a good inter-observer agreement in the assessment of venography was observed between the central and local adjudication in a study on DVT prevention run in a restricted experienced study framework. The cost and work overloading of central assessment of venographies in this study framework seems not to be justified.
Contribution of the -455G/A Polymorphism at the β-fibrinogen Gene to Erythrocyte Aggregation in Patients with Coronary Artery Disease
Authors: Weng Xiaoduan , Genest Jacques , Cloutier Guy
Published: March 2018

Background. A high level of red blood cell (RBC) aggregation has been consistently found in patients with coronary artery disease (CAD) in case-control studies. Plasma fibrinogen has been shown to promote RBC aggregability. The purpose of this study was to investigate the influence of the genetic variability of the β-fibrinogen gene on RBC aggregation in patients with CAD. Methods and Results. The genotype of the β-fibrinogen gene locus was determined by polymerase chain reaction using the restriction enzyme HaeIII for a G to A substitution at position -455 upstream from the transcriptional start site in 135 French Canadians with premature CAD (age: 51 ± 7 years). Indices measuring the RBC aggregation kinetics (S10) and shear resistance of the aggregates (γS) were obtained by laser reflectometry. Patients were separated into groups by using the medians of S10 and γS. Using χ2 analyses, the distribution of the -455GG, -455GA, and -455AA genotypes in the groups with high levels of S10 (0.43, 0.49, and 0.08) and γS (0.45, 0.49, and 0.06) were found to be significantly distinct from those in the groups with low levels of S10 (0.67, 0.27, and 0.06; p <0.05) and γS (0.70, 0.23, and 0.07; p <0.01). High levels of RBC aggregation were closely associated with the rare -455A allele. Multivariate linear regression analyses showed that S10 was positively correlated with the linear combination of the fibrinogen concentration, age, and the -455G/A genotype (adjusted r = 0.63, p <0.0001). Fibrinogen and age were positive determinants, and HDL-cholesterol was a negative predictor of γS (adjusted r = 0.51, p <0.0001). Conclusion. These findings support the hypothesis that RBC hyperaggregation in premature CAD may be associated with the β-fibrinogen -455G/A polymorphism. This association may be explained by a change in the concentration and/or the functional properties of the fibrinogen protein.
Factor IX Gene Analysis In 70 Unrelated Patients with Haemophilia B: Description of 13 New Mutations
Authors: Trzeciak M. C. , Durin A. , Pernod G. , Gay V. , Ménart C. , Sobas F. , Dechavanne M. , Attali O. , Vinciguerra C. , Négrier C.
Published: March 2018

Seventy unrelated patients suffering from haemophilia B have been screened for determining the molecular defect and for evaluating the spectrum of factor IX mutations in the Rhône Alpes region in France. Most patients were characterized with respect to factor IX antigen and factor IX coagulant activity. We have used denaturing gradient gel electrophoresis to obtain a full scanning of the whole coding, promoter, and exon flanking sequences of the factor IX gene. This technique enabled us to determine the molecular defect in 68 out of 70 families (97%), and the mutation was further identified in the two last patients with a direct sequencing of the gene. A total of 2 complete gene deletions in patients with antifactor IX inhibitor, 6 small insertions/ deletions and 62 point mutations were found. Two of these nucleotide substitutions (Arg145His and Ala233Thr) were detected in 21 patients (30%) suggesting the existence of a local founder effect. Thirteen mutations were previously undescribed, including 7 missense mutations. The detection of mutations in patients affected with haemophilia B may shed some light in the structure-function relationship of factor IX molecule within the coagulation system.
Variations in Coagulation Factors in Women: Effects of Age, Ethnicity, Menstrual Cycle and Combined Oral Contraceptive
Authors: Kadir Rezan , Sabin Caroline , Owens Dale , Lee Christine , Economides Demetrios
Published: March 2018

To assess variations of coagulation factors in women, 123 women were included in a cross-sectional study of the effect of age, ethnic origin, blood group and menstrual cycle on surface induced coagulation time (activated partial thromboplastin time) and plasma levels of Factor VIII clotting assay, von Willebrand factor antigen, von Willebrand factor activity and factor XI. The effect of menstrual cycle was further assessed in a longitudinal study including 39 Caucasian women, 20 of whom were using combined oral contraceptives. Activated partial thromboplastin time was longer in women with blood groups B or O, and plasma levels of factor VIII clotting assay, von Willebrand factor antigen and von Willebrand factor activity were significantly higher in black women. Fibrinogen, von Willebrand factor antigen and von Willebrand factor activity concentrations showed strong cyclic variations with peak values in the luteal phase. This pattern was dampened for von Willebrand factor antigen and von Willebrand factor activity but completely disappeared for fibrinogen with the use of combined oral contraceptives. There was a cyclical pattern for factor VIII clotting assay in pill users, evidence of which was not evident in non-pill users. There were strong associations between the levels of von Willebrand factor antigen and von Willebrand factor activity and age, with levels rising by an average of 0.17 and 0.15 U/ml, respectively, for each 10 year increase in age. In conclusion, there are great inter- and intraindividual variations in coagulation markers in women due to different physiological conditions such as age, ethnicity, blood group and phases of the menstrual cycle. However, there were no significant associations between coagulation markers and weight, alcohol consumption or smoking status.
Abnormal Fibrin Clot Architecture in Nephrotic Patients Is Related to Hypofibrinolysis: Influence of Plasma Biochemical Modifications
Authors: Mishal Zohar , Lesty Claude , Mirshahi Manoucher , Peynet Jacqueline , Baumelou Alain , Bensman Albert , Soria Jeannette , Soria Claudine , Collet Jean-Philippe
Published: March 2018

Porosity, viscoelasticity and morphological properties of plasma fibrin from 16 nephrotic patients and 16 healthy volunteers were compared. Nephrotic patients were characterized by formation of tight and rigid plasma fibrin gels which resulted in a slower rate of fibrin lysis studied either under pressure-driven permeation or diffusional transport of fibrinolytic agents. These latter findings indicated that both abnormal fibrin network conformation and abnormal fibrin fiber structure were involved in hypofibrinolysis. Albumin supplementation up to 40 mg/ml partially restored normal fibrin architecture and increased the rate of fibrinolysis in these patients. Multiparametric analysis showed that nephrotic patients were mainly characterized by a low plasma albumin level (R = -0.85), a low albumin to fibrinogen ratio (R = -0.89) and a high resistance to lysis (R = -0.82). High triglycerides level was the only plasma modification related to the slower fibrin lysis rate (R = -0.54). High fibrin rigidity (G’) was the only fibrin parameter simultaneously related to the nephrotic state (R = 0.75) and the lysis resistance (R = -0.71). After eliminating the effects of age, albumin and fibrinogen levels, low fibrin porosity (Ks) and low fiber mass-length ratio (μ) were the main features of the nephrotic state. These findings are discussed in relation to both the pathophysiology of thrombotic complications in nephrotic syndrome and their pharmacological prevention.
Molecular Analyses of the Platelet Glycoprotein Ib-IX-V Receptor
Authors: Ware Jerry
Published: March 2018

Introducation

Glycoprotein receptors within the platelet membrane are essential for initiating platelet adhesion and aggregation on thrombogenic surfaces. As a response to vascular injury these receptors provide platelets with two essential properties i) the ability to bind adhesive substrates exposed at the site of injury (adhesion) and ii) the ability to recruit additional platelets to form a thrombus (aggregation). It is becoming increasingly evident that defined rheological conditions govern the physiological relevance of specific receptor-ligand interactions along with fundamentally distinct molecular mechanisms for individual receptors and their ligands. Among platelet receptors the glycoprotein (GP) Ib-IX-V complex is important because it initiates thrombus formation over a wide range of flow conditions through an initial interaction with the adhesive ligand, von Willebrand factor. The importance of this receptor-ligand interaction is best exemplified by congenital bleeding disorders resulting from the lack of either the receptor or the ligand, the Bernard-Soulier syndrome and von Willebrand disease, respectively. Additionally, the GP Ib component of the GP Ib-IX-V complex contains a binding site for α-thrombin and recent studies have strengthened the concept that the interaction between α-thrombin and GP Ib is of biological relevance. Unquestionably, studies dissecting the GP Ib-IX-V complex are defining essential aspects of normal hemostasis and thrombosis while providing key information on the molecular mechanisms governing the formation of pathologic platelet thrombi. This review will summarize recent advances in our understanding of the synthesis, structure and function of the platelet GP Ib-IX-V complex. Where possible, directions for future studies will be identified with an overall goal of achieving a more complete understanding on the role of the GP Ib-IX-V complex in platelet biology.
Abnormal Expression of Type 1 Plasminogen Activator Inhibitor and Tissue Factor in Severe Preeclampsia
Authors: Gilabert Juan , Grancha Salvador , Yamamoto Koji , Thinnes Terri , España Francisco , Aznar Justo , Loskutoff David , Estellés Amparo
Published: March 2018

Preeclampsia is a multisystemic obstetric disease of unknown etiology that is commonly associated with fibrin deposition, occlusive lesions in placental vasculature, and intrauterine fetal growth retardation. We previously reported that type 1 plasminogen activator inhibitor (PAI-1) levels are significantly increased in plasma and placenta from pregnant women with preeclampsia compared to normal pregnant women. In the present report we localize the expression of placental PAI-1 in greater detail and compare it with that of tissue factor (TF), a procoagulant molecule, and vitronectin (Vn), a PAI-1 cofactor. We also examine the expression of two cytokines, tumor necrosis factor α (TNFα) and interleukin-1 (IL-1), in order to begin to define the underlying mechanisms responsible for the elevated levels of PAI-1 and fibrin deposits observed in placenta from preeclampsia. We demonstrate a significant increase in PAI-1, TF and TNFα antigen and PAI-1 and TF mRNA in placentas from preeclamptic patients. PAI-1 mRNA was increased not only in syncytiotrophoblast and infarction areas, but also in fibroblasts and in some endothelial cells of fetal vessels in placentas from preeclamptic patients. However, there was no colocalization between PAI-1, TF, Vn and TNFα in placental villi. The elevated TNFα in the placenta may induce PAI-1 and TF, and thus promote the thrombotic alterations associated with preeclampsia.
Feasibility Study of Catheter-directed Thrombolysis with Recombinant Staphylokinase in Deep Venous Thrombosis
Authors: Heymans Stephane , Verhaeghe Raymond , Stockx Luc , Collen Désiré
Published: March 2018

The feasibility of catheter-directed thrombolysis with recombinant staphylokinase was evaluated in six selected patients with deep vein thrombosis. The patients underwent intrathrombus infusion of recombinant staphylokinase (2 mg bolus followed by a continuous infusion of 1 mg/h). Heparin was given via the catheter as a bolus (5000 U) and as a continuous infusion (1000 U/h). Complete lyis was obtained in five patients and partial lysis in one patient. Complications consisted of minor bleeding in four subjects. Symptomatic reocclusion occurred in one. Debulking of the thrombus mass by a high speed rotating impeller (n = 1) and stenting (n = 3) were used as additional interventions. An underlying anatomical abnormality was present in two patients. Long term follow up revealed normal patency in all patients and normal valve function in four patients. Symptomatic venous insufficiency with valve dysfunction was present in the two with a second thrombotic episode.

Thus catheter-directed infusion of recombinant staphylokinase in patients with deep vein thrombosis appears feasible and may be associated with a high frequency of thrombolysis. Larger studies to define the clinical benefit of this treatment appear to be warranted.
Sensitivity, Specificity and Predictive Value of Modified Assays for Activated Protein C Resistance in Children
Authors: Brandt Greg , Glueck Charles , Stroop Davis , Becker Ann , Pillow Ann , Wang Ping , Gruppo Ralph
Published: March 2018

Very little data is available assessing the clinical utility of coagulation-based APC resistance assays compared to DNA-based analysis for the factor V Leiden mutation in children. Therefore, the clinical utility of four aPTT-based assays for APC resistance was evaluated in 169 children, ages 3 months through 16 years. The prevalence of the Arg506 to Gln mutation was 7/169 (4.1%). Using cutoff points derived from the normal PCR-screened population (n = 162), two assays for APC resistance (APC-SR and n-APC-SR) gave poor concordance with the PCR assay (sensitivity 29% and 57%, respectively). Two modified assays (FDAPC-SR and n-FDAPC-SR), in which patient plasma was prediluted 1:5 in factor V deficient plasma, gave excellent concordance (sensitivity 100%). The predictive value of a positive test was 0.25, 0.44, 1.00 and 0.88 for the APC-SR, n-APC-SR, FDAPC-SR and n-FDAPC-SR, respectively. The FDAPC-SR and n-FDAPC-SR tests gave excellent discrimination using cutoff values derived from the total population (n = 169) without regard to previous PCR screening results.
Relation of Urokinase-Type Plasminogen Activator Expression to Presence and Severity of Atherosclerotic Lesions in Human Coronary Arteries
Authors: Padró Teresa , Steins Martin , Li Chang-Xun , Schmid Kurt , Hammel Dieter , Scheld Hans , van de Loo Jürgen , Kienast Joachim
Published: March 2018

Urokinase-type plasminogen activator (UPA) has been implicated in a broad spectrum of pathological processes – e.g. cell adhesion, migration and proliferation and matrix remodeling – that are considered important features of atherogenesis and plaque disruption. In this study, we have analyzed the content and expression of UPA in human coronary arteries and its relation to the presence and severity of atherosclerotic lesions. Segments of coronary arteries obtained from human heart explants (n = 15) were classified by the presence and types of atherosclerotic lesions. UPA was quantitatively determined in protein extracts of the intimal and medial layers. In situ hybridization and immunohistochemical analyses were performed on serial sections of representative tissue specimens. UPA was detected in the extracts as pro-UPA, UPA complexed to plasminogen activator inhibitor-1, or as otherwise inactive UPA antigen, but not in the active two-chain form. Both functional and total UPA were increased several-fold in extracts of advanced lesions, while the ratios of functional over total UPA showed the opposite trend suggesting enhanced UPA inactivation and turnover. UPA expression in early atherosclerotic lesions was particularly prominent in areas of proliferating SMCs in the abluminal part of the neointima, whereas in advanced lesions UPA was widely expressed in macrophage-rich areas adjacent to the rims and shoulder regions of the necrotic cores. The results strongly suggest a causal involvement of UPA in coronary atherogenesis and its clinical outcome.
Alboaggregins A and B. Structure and Interaction with Human Platelets
Authors: Tan Li , Holt John , Peng Manling , Karczewski Jerzy , Calvete Juan , Kowalska Anna , Niewiarowski Stefan
Published: March 2018

Viper venoms contain a variety of platelet binding proteins including those which bind to platelet GPIb/GPIX. Most of these proteins inhibit von Willebrand factor mediated platelet agglutination. Here we report the primary structures of unique members of this family, alboaggregins A and B, isolated from Trimeresurus albolabris, which have the ability to stimulate platelet agglutination and aggregation. Four chains of alboaggregin A and two chains of alboaggregin B share a high degree of homology and all cysteines in both alboaggregins are conserved. Both alboaggregins caused similar agglutination of fixed platelets. Alboaggregin A induced platelet aggregation and release reaction with EC50 = 10 and 30 nM, respectively, which is 20-fold lower than those for alboaggregin B. These observations suggest that the dimeric structure of alboaggregin B is sufficient to mediate its binding to GPIb and induce agglutination of platelets whereas aggregation and release reaction are significantly enhanced by tetrameric structure of alboaggregin A.
Prospective, Randomised Trial of Two Doses of rFVIIa (NovoSeven) in Haemophilia Patients with Inhibitors Undergoing Surgery
Authors: Gilchrist Gerald , Hoots W. Keith , Cooper Herbert , Gastineau Dennis , Shapiro Amy
Published: March 2018

Recombinant factor VIIa (rFVIIa; NovoSeven® ; Novo Nordisk) has proven efficacy in the treatment of haemophilic patients with inhibitors. This prospective, double-blind study compared rFVIIa (35 vs. 90 μg/kg) in the initiation and maintenance of haemostasis during and after elective surgery. Patients with inhibitors (FVIII, n = 26; FIX, n = 3) received rFVIIa immediately prior to incision; intraoperatively as needed; every 2 h for the first 48 h; and every 2-6 h for the following 3 days. Haemostasis was evaluated during surgery, at 0, 8, 24 and 48 h and 3, 4 and 5 days after wound closure. After day 5, open-label rFVIIa (90 μg/kg) was available for maintenance. Intraoperative haemostasis was achieved in 28/29 patients. All high-dose patients and 12/15 low dose patients had satisfactory haemostasis during the first 48 h. Twenty-three patients (13/14 high dose) successfully completed the study. Although the 35 μg/kg dose is probably sub-optimal for post-operative management, at least in major procedures, rFVIIa 90 μg/kg is an effective first-line option in surgery for patients with inhibitors.
French Previously Untreated Patients with Severe Hemophilia A after Exposure to Recombinant Factor VIII : Incidence of Inhibitor and Evaluation of Immune Tolerance
Authors: Laurian Y. , Satre E. P. , Derlon A. Borel , Chambost H. , Moreau P. , Goudemand J. , Parquet A. , Peynet J. , Vicariot M. , Beurrier P. , Claeyssens S. , Durin A. , Faradji A. , Fressinaud E. , Gaillard S. , Guérin V. , Guérois C. , Pernod G. , Pouzol P. , Schved J. F. , Gazengel C. , Rothschild C.
Published: March 2018

Fifty French previously untreated patients with severe hemophilia A (factor VIII <1%), treated with only one brand of recombinant factor VIII (rFVIII), were evaluated for inhibitor development, assessment of risk factors and outcome of immune tolerance regimen. The median period on study was 32 months (range 9-74) since the first injection of rFVIII. Fourteen patients (28%) developed an inhibitor, four of whom (8%) with a high titer (≥10 BU). All inhibitor patients but one continued to receive rFVIII either for on-demand treatment or for immune tolerance regimen (ITR). Among these patients, inhibitor was transient in 2 (4%), became undetectable in 6 and was still present in 6. The prevalence of inhibitor was 12%. Presence of intron 22 inversion was found to be a risk factor for inhibitor development. Immune tolerance was difficult to achieve in our series despite a follow-up period of 16 to 30 months: immune tolerance was complete in only one out of the 3 patients undergoing low dose ITR and in one out of the 5 patients with high dose ITR.
Topological Studies of the Amino Terminal Modules of Vitamin K-dependent Protein S Using Monoclonal Antibody Epitope Mapping and Molecular Modeling
Authors: Giri Tusar , Villoutreix Bruno , Wallqvist Anders , Dahlbäck Björn , Frutos Pablo García de
Published: March 2018

Protein S is an important anticoagulant protein acting as cofactor to activated protein C (APC) in the degradation of membrane-bound factors Va and VIIIa. Binding of protein S to the membrane depends on the Gla-domain, whereas sites for APC-interaction are located in the thrombin-sensitive region (TSR) and the first EGF domain. The aims of the present investigation were to localize the sites on protein S which are involved in APC-cofactor function and to elucidate possible orientations of the TSR in relation to the membrane. For these purposes, we determined the epitope for a calcium-dependent monoclonal antibody (HPS67) against the TSR, which inhibits APC cofactor activity even though it does not impede protein S binding to the membrane. HPS67 did not recognize wild-type mouse protein S but gained reactivity against a recombinant mouse protein in which G49 and R52 were mutated to R and Q (found in human protein S), respectively, suggesting these two residues to be part of a surface exposed epitope for HPS67. This information helped in the validation and refinement of the structural model for the Gla-TSR-EGF1-modules of protein S. The X-ray structure of a Fab-fragment mimicking HPS67 was docked onto the protein S model. The observation that HPS67 did not inhibit phospholipid binding of protein S has implications for the possible orientation of protein S on the membrane surface. In the proposed model for membrane-bound protein S, there is no contact between the TSR and the membrane. Rather, the TSR is free to interact with membrane-bound APC.
Fibrinogen Plasma Levels in an Apparently Healthy General Population – Relation to Environmental and Genetic Determinants
Authors: Cappucci Giuseppe , Colaizzo Donatella , Pirro Leonardo , Vecchione Gennaro , Grandone Elvira , Minno Giovanni Di , Margaglione Maurizio
Published: March 2018

Elevated fibrinogen levels are an independent risk factor for cardiovascular ischemic disease. We investigated the relationship between cardiovascular ischemic risk factors, the fibrinogen Bβ-chain G/A-455 polymorphism and plasma fibrinogen levels in 989 apparently healthy subjects. Fibrinogen values were higher in subjects with C reactive protein (C-RP) > 0.33 mg/dl, BMI > 23.9 kg/m2, total cholesterol > 4.84 mmol/l, triglycerides >1.02 mmol/l, PAI-1 antigen >12.2 ng/ml, carriers of the A allele, first-degree relative history of coronary artery disease, or consuming >10 cigarettes per day (p <0.01). Men and ethanol drinkers showed lower plasma fibrinogen levels (p <0.01). The multivariate analysis confirmed the independent effect of C-RP, age, BMI, total cholesterol, gender, PAI-1, -455 G/A polymorphism, (p <0.05). BMI, total cholesterol, PAI-1, alcohol and smoking habit raised with the increase of age and differed between sexes. The A-455 allele increasing effect was significant in women, especially in subjects aged <30 years, and in men aged <43 years. These results indicate that environmental factors contributed to a larger extent to fibrinogen variability, whereas the A-455 allele was associated with a steeper increase in younger age quartiles.
Localization and Translocation of MMP-2 during Aggregation of Human Platelets
Authors: Sawicki Grzegorz , Sanders Esmond , Salas Eduardo , Wozniak Mieczyslaw , Rodrigo Jose , Radomski Marek
Published: March 2018

We have previously shown that human platelets express matrix metalloproteinase-2 (MMP-2) and that the release of this enzyme during platelet activation mediates the ADP- and thromboxane-independent part of aggregation. We have now used immunogold electron microscopy, flow cytometry, Western blot analysis and zymography methods to study the ultrastructural localization of MMP-2 in human washed platelets. Platelet aggregation was stimulated by collagen and the MMP-2 immunoreactivity of platelets was followed during various stages of aggregation. In resting platelets, MMP-2 was randomly distributed in the platelet cytosol without detectable association with platelet granules. Platelet aggregation caused the translocation of MMP-2 from the cytosol to the extracellular space. During the early stages of aggregation, MMP-2 remained in close association with the platelet plasma membrane. We conclude that the interactions of MMP-2 with platelet surface membranes mediate the aggregatory response induced by this enzyme.
Vitamin E, Atherosclerosis and Thrombosis
Authors: Micheletta Fausta , Iuliano Luigi , Violi Francesco
Published: March 2018

Vitamin E, a major lipid-soluble, chain-breaking antioxidant includes several tocopherols having the biological activity of RRR-alpha-tocopherol. Vitamin E circulates in the blood as free tocopherol bound to beta-lipoproteins and is present in cell membrane where it exerts a potent defence against lipid peroxidation (1). Blood concentration of vitamin E in humans ranges from 25 to 30 μM, depending on daily intake and body’s ability to absorb fat (1). In the last decade the scientific interest on biological activity of vitamin E increased because of a growing body of evidence linking this vitamin with atherosclerosis and its complications (2). Thus, the oxidative hypothesis of atherosclerosis suggests that LDL accumulates within vessel wall, in particular in the macrophages, as a consequence of its oxidative modification mediated by resident cells (3, 4). A reduced defence against LDL oxidation could favour this process and accelerate atherosclerotic progression. Accordingly, patients with coronary heart disease have lower plasma concentration of vitamin E than controls (2) and prospective studies demonstrated that a daily assumption of vitamin E reduces cardiovascular events (5). According to the oxidative hypothesis of atherosclerosis, this effect has been attributed to the inhibition of LDL oxidation. Alternative mechanism potentially implicated in the antiatherosclerotic activity of vitamin E includes its interference with the activity of platelet and monocyte, in which the intracellular redox status plays an important functional role (6, 7). As platelets and monocytes are both involved in the pathophysiologic process leading to atherosclerotic lesion, the interference of vitamin E with the biological function of these cells may represent another important tool to explore the anti-atherosclerotic activity of vitamin E. This review will focus on the open issues related to the use of vitamin E in clinical studies and the potential usefulness in investigating platelet function and clotting activation in patients treated with vitamin E.
Plasma Levels of Syndecan-4 (Ryudocan) Are Elevated in Patients with Acute Myocardial Infarction
Authors: Takagi Akira , Maeda Masahiro , Segawa Tatsuya , Shimizu Atsuya , Yamamoto Koji , Matsushita Tadashi , Saito Hidehiko , Kojima Tetsuhito
Published: March 2018

Syndecan-4 (ryudocan) is a cell-surface heparan sulfate proteoglycan, which plays an important role in a variety of biological functions including regulation of blood coagulation, cell adhesion, and cell growth. In this study, we measured plasma levels of syndecan-4 in patients with acute myocardial infarction using an enzyme-immunoassay, and found that they were extremely high, with a peak of average (10.5 ± 5.6 ng/ml, 2 weeks after onset), as compared with those in normal subjects (0.078 ± 0.030 ng/ml) (p < 0.001). We also observed a distinct expression of syndecan-4 in the repair region of the damaged cardiac tissues with infarction, but not in intact region, by immunohistochemical analysis. To clarify the mechanism of syndecan-4 induction, we investigated the hypoxia effect on its expression, and found that hypoxia treatment up-regulated the gene expression of syndecan-4 in various types of cells. Taken together, it is suggested that syndecan-4 is induced by hypoxia stimuli in ischemic heart tissues, and may function as a tissue-repair molecule via biological mediators such as heparin-binding growth factors.
Antibodies to Phosphatidylethanolamine as the only Antiphospholipid Antibodies Found in Patients with Unexplained Thromboses
Authors: Alessi Marie-Christine , Harle Jean Robert , Sapin Christophe , Aillaud Marie-Françoise , Gentile Stéphanie , Juhan-Vague Irène , Weiller Pierre-Jean , Sanmarco Marielle
Published: March 2018

The objective of this study was to assess the interest of antiphosphatidylethanolamine antibodies (aPE) in unexplained thrombosis (UT) defined as thrombotic episode without any of the main autoimmune and hereditary thrombophilic defects. Results from 98 UT were compared to those of (I) 142 patients with thrombophilia: 67 antiphospholipid syndrome (APS) and 75 hereditary hemostatic defects (HHD); (II) 110 patients without thrombosis: 60 with systemic lupus erythematosus (SLE) and 50 with infectious diseases (ID). As compared to controls (100 blood donors), aPE prevalence was significantly higher in both autoimmune contexts (APS: 43%; SLE: 40%, p <0.0001) and among non-autoimmune pathologies, only in UT (18%, p = 0.001) conversely to HHD (8%) or ID (10%). aPE prevalence in UT was not statistically different from that found in Primary APS (32%, p = 0.076) but lower than in Secondary APS (65%, p <0.005). In UT, aPE were mainly of IgM isotype like in Primary APS and they were found alone whereas in SLE they were always associated with classical anti-phospholipid antibodies. No significant association was found between any isotype of aPE and a site of thrombosis in UT as well as in APS. In conclusion, this study demonstrates an increase of the prevalence of aPE in patients with unexplained thrombosis. Thus, aPE investigation appears to be of interest in UT and their persistent presence could define a biological variant of APS.
Pharmacokinetic Studies with FVIII/von Willebrand Factor Concentrate Can Be a Diagnostic Tool to Distinguish between Subgroups of Patients with Acquired von Willebrand Syndrome
Authors: Lubetsky A. , Schliamser L. , Kotler A. , Tamarin I. , Luboshitz J. , Inbal A.
Published: March 2018

Acquired von Willebrand syndrome (AVWS) has been associated mainly with monoclonal gammopathy of uncertain significance (MGUS), clonal lymphoproliferative or myeloproliferative disorders and autoimmunity. In the present work we studied 6 patients with AVWS: four with MGUS IgG (λ or κ), one with small lymphocytic lymphoma and one with agnogenic myeloid metaplasia (AMM). All the patients underwent a pharmacokinetic analysis at presentation in order to study potential differences in recovery, clearance (CL) or terminal half-life (THL) following administration of von Willebrand factor (VWF) concentrate. In all the patients with AVWS an increase in clearance and a decrease in THL was observed as compared to these parameters in patients with hereditary type 3 von Willebrand disease (VWD). No difference in recovery was observed among the groups. The increase in clearance and the decrease in THL were significantly more pronounced in the group of MGUS patients (57.93 ± 25.6 ml/h/kg, and 1.39 ± 0.5 h, respectively) as compared to these parameters in the AMM (8.06 ml/h/kg, and 6.96 h, respectively) or the lymphoma (4.76 ml/h/kg, and 6.76 h, respectively) patients (p = 0.03 for clearance and 0.001 for THL). These data indicate that the pharmacokinetic analysis can be a useful tool to distinguish between MGUS-related and other causes of AVWS, and to plan an appropriate treatment accordingly.
Extracellular Nucleotides ATP and UTP Induce a Marked Acute Release of Tissue-type Plasminogen Activator In Vivo in Man
Authors: Hrafnkelsdóttir Thórdís , Erlinge David , Jern Sverker
Published: March 2018

Extracellular nucleotides such as ATP and UTP are released by activation of platelets and ischemic tissue injury. The aim of the present study was to investigate whether ATP and UTP can induce acute tPA release from the vascular endothelium in vivo. Nine healthy subjects were studied in a perfused-forearm model during stepwise intraarterial infusions of ATP and UTP (10-200 nmol/min), and UTP during inhibition of prostanoid and NO synthesis by indomethacin and L-NMMA. ATP and UTP induced a similar and marked stimulation of forearm tPA release which increased 11- and 18-fold above baseline (p ≤ 0.01 for both) in conjunction with pronounced vasodilation. Neither the acute tPA release nor the vasodilation could be abrogated by NO and prostanoid synthesis inhibition. The similar effect of ATP and UTP suggests that P2Y rather than adenosine receptors mediate the response. Release of extracellular nucleotides in ischemic tissue may induce a pronounced activation of the endogenous fibrinolytic system.
Telesprachtherapie (Synchrotel) bei Aphasie nach Schlaganfall
Authors: Richter J. , Scibor M. , Keidel M. , Vauth F.
Published: March 2018

In einer prospektiven Studie wurde die Effizienz telemedizinischer Online-Sprachtherapie bei Schlaganfall-Patienten überprüft. Studienziel war es, die Tele-Online-Therapie als neue zusätzliche Therapieform zu etablieren. Tele-Online-Sprachtherapie ist speziell für schwer und schwerstbetroffene chronische Patienten mit nicht flüssiger Aphasie geeignet. Sie bietet die Möglichkeit, Sprachtherapie hochfrequent und intensiv anzubieten. Dadurch können häufige Klinikaufenthalte eingespart werden. Es wurde eine neue Therapiemethode und spezifisch dafür konzipiertes Therapiematerial entwickelt: Das Konzept der interaktions-, emotions- und motivationsfokussierten Sprachtherapie. Die Ergebnisse bestätigen, dass Tele-Online-Therapie gleiche Wirkeffekte wie konventionelle Sprachtherapie zeigt. Entgegen der Ausgangserwartung zeigen sich häufiger positive Veränderungen in der Tele-Online-Therapiegruppe.
Pharmakotherapie des Parkinson
Authors: Ceballos-Baumann A. O. , Fietzek U. M.
Published: March 2018

Die Suche nach besseren symptomatischen Parkinson-Therapeutika hat in den letzten Jahren zahlreiche Neuentwicklungen hervorgebracht. Levodopa ist weiterhin zentraler Therapiebaustein. Die Hersteller suchen nach Wegen, um den Nachteil der kurzen Plasmahalbwertszeit dieser Aminosäure zu kompensieren. In den USA ist eine neue Levodopa-Carbidopa-Galenik mit einer langsameren Wirkstoffreissetzung für fluktuierende Parkinson-Patienten neu auf dem Markt. Hierzu werden eine inhalative und eine subkutane Darreichungsform des Levodopa klinisch geprüft. Der einzige erst jüngst neu zugelassene neue Wirkstoff seit 2007, das Safinamid, beeinflusst die Monoaminooxidase (MAO) sowie den Glutamatstoffwechsel und verspricht mehr dopaminerge Wirkung ohne Auslösung von Dyskinesien. Neue COMT-Inhibitoren sollen ebenso das Levodopa mittels einer Hemmung dieses Abbauweges besser verfügbar machen. Ältere Substanzen wie der NMDA-Inhibitor Amantadin werden neu aufgelegt, um Levodopa induzierte Dyskinesien zu behandeln. Die Gruppe der mGluR5-Antagonisten zielen ebenso auf diese Indikation ab. Mehrere Adenosinantagonisten wurden entwickelt, um über nicht dopaminerge Mechanismen Parkinson-Symptome zu reduzieren. Das Pimavanserin ist ein inverser Serotoninagonist der an psychotischen Parkinson-Patienten erfolgreich geprüft wurde. Eine Studie zu parkinsonassoziierten Schmerzen untersuchte die Kombination Oxycodon und Naloxon bei schweren Schmerzen mit gemischten Ergebnissen. Noch nicht einzuschätzen sind die Möglichkeiten immunotherapeutischer Ansätze, z. B. die „Parkinson-Impfung“ und monoklonale Antikörper, gegen Alphasynuklein, die inzwischen klinisch untersucht werden.
Traumafolgestörungen in der Bundeswehr
Authors: Wesemann U. , Willmund G. , Alliger-Horn C. , Zimmermann P.
Published: March 2018

Die Bundeswehr ist seit 1991 in Auslandseinsätzen engagiert. Der Stellenwert psychischer Erkrankungen hat sich in dieser Zeit deutlich erhöht und stellt nun eine erhebliche Herausforderung für Prävention und Therapie dar. Ziel dieses Beitrages ist es, einen Überblick über aktuelle Entwicklungen in den Bereichen Prävention, Behandlung, Begutachtung und Forschung zu psychischen Erkrankungen in der Bundeswehr zu geben und zu diskutieren.
Neuronale Korrelate emotionaler Dysregulation bei Patienten mit Borderline-Persönlichkeitsstörung
Authors: Viviani R. , Sosic-Vasic Z. , Schauer J. S.
Published: March 2018

Die Borderline-Persönlichkeitsstörung (BPS) ist eine schwerwiegende psychiatrische Erkrankung, die insbesondere durch eine Störung der Emotionsregulation gekennzeichnet ist. Gängige neuronale Modelle der Emotionsregulation gehen davon aus, dass zwei Prozesse in diesem Zusammenhang von Bedeutung sind: einerseits ein ventrales neuronales Netzwerk, welches für die Emotionsentstehung entscheidend ist (bottom-up) und andererseits präfrontale neuronale Strukturen, die mittels kognitiver Kontrollmechanismen der Emotionsregulation dienen (top-down). Neuere Forschung weist auf die Bedeutung impliziter Emotionsregulation unabhängig von exekutiven Funktionen hin. Untersuchungen zu neuronalen Korrelaten emotionaler Dysregulation bei der BPS finden vor allem eine Hyperreaktivität der Amygdala, die als erhöhte Sensibilität für emotionale Reize und Grundlage emotionaler Instabilität gedeutet werden kann. Psychotherapeutische Ansätze zeigen dazu passend eine Reduktion dieser erhöhten emotionalen Sensitivität im Sinne reduzierter Amygdalaaktivierung in Folge der Behandlung. In Bezug auf die Mechanismen einer veränderten Emotionsregulation bleiben die Befunde uneindeutig, was der geringen Stichprobengröße und großen Methodenvariabilität, aber auch einer notwendigen Erweiterung von Emotions-regulationsmodellen geschuldet sein kann.
Clinical Prediction of Lower Limb Deep Vein Thrombosis in Symptomatic Hospitalized Patients
Authors: Nelzy M. L. , Salmi L. R. , Skopinski S. , Saby J. C. , Le Métayer P. , Morlat P. , Conri C. , Constans J.
Published: March 2018

We evaluated two clinical scores for the prediction of deep venous thrombosis (DVT) in hospitalized patients (Wells’ and Kahn’s). We included 273 patients referred to the vascular exploration unit for the suspicion of DVT. A clinical questionnaire was filled in by the practitioner and the scores were calculated from this form. 66 of the 273 patients had a DVT. When Wells’ score was 3, a DVT was found by duplex echography in 51% patients ; when the score was 0, a DVT was found in 9%. Kahn’s score was not adapted to this population. We then developed a new simple score (cancer, palsy or plaster immobilization, warmth, superficial venous dilation, unilateral pitting edema, other diagnosis). A DVT was found in 76% patients with a score of 3 and in 11% in those with a score of 0. We therefore propose a 6-item score whose main advantages are simplicity and usefulness in routine practice.
Creation of an Additional Glycosylation Site as a Mechanism for Type I Antithrombin Deficiency
Authors: Lewandowski Krzysztof , Olds Robin , Fitches Alison
Published: March 2018

We report the identification of a new mutation resulting in type I antithrombin (AT) deficiency and the mechanism by which the deficiency arose. The single base substitution of G to A at nucleotide 2709 was identified in a proband with a family history of venous thrombosis. The mutation results in a substitution of 82 Ser by Asn, creating a new glycosylation site. Expression studies were then carried out, to confirm Asn-linked glycosylation occurred at this consensus site and that this resulted in the AT deficient phenotype. Cell-free translations using rabbit reticulocyte lysate in the presence of microsomes demonstrated that the 82 Asn variant was post-translationally processed efficiently. The 82 Asn variant protein was of a higher molecular weight than normal AT, consistent with the addition of a fifth glycan chain. Incubation of translation product with endoglycosidase H, confirmed that the higher molecular weight product had resulted from additional carbohydrate. Expression of the 82 Asn variant in COS-7 cells resulted in intracellular accumulation, with a low level of secretion of the protein into culture supernatant, consistent with type I AT deficiency. The addition of an extra carbohydrate side chain to residue 82 of antithrombin may block post-translational folding, trapping the variant intracellulary.
The Role of Protein S in the Activation of Thrombin Activatable Fibrinolysis Inhibitor (TAFI) and Regulation of Fibrinolysis
Authors: Mosnier Laurent , Meijers Joost , Bouma Bonno
Published: March 2018

Thrombin activatable fibrinolysis inhibitor (TAFI) is a carboxypeptidase B-like proenzyme that after activation by thrombin downregulates fibrinolysis. Thrombomodulin stimulates the activation of both TAFI and protein C whereas activated protein C inhibits the activation of TAFI by downregulation of thrombin formation, a process in which protein S acts as a cofactor. Here we determined the role of protein S in the activation of TAFI and regulation of fibrinolysis. Depletion of protein S from plasma or inhibition of protein S by specific antibodies resulted in an increased rate of TAFI activation and in an increased maximum of TAFIa activity generated. The effect on the rate of TAFI activation could be attributed to the APC-independent anticoagulant function of protein S whereas the effect on the maximum activity could be attributed to the APC cofactor function of protein S. Therefore it is concluded that protein S inhibits TAFI activation in two ways. On one hand, protein S functions as a cofactor for APC which results in a reduction of the maximum induced TAFI activity and on the other hand protein S inhibits the initial thrombin formation independently of APC which results in a decreased rate of TAFI activation. The effect of the APC-independent anticoagulant activity of protein S on the activation of TAFI provides a new mechanism for the regulation of fibrinolysis in the early stages of clot formation.
A Hamster Antibody to the Mouse Fibrinogen Chain Inhibits Platelet-fibrinogen Interactions and FXIIIa-mediated Fibrin Cross-linking, and Facilitates Thrombolysis
Authors: JirouȈsková Markéta , Smyth Susan , Kudryk Bohdan , Coller Barry
Published: March 2018

Murine models employing genetically altered mice have the potential to provide important new information about the hemostatic system, but before such data can be extrapolated to humans it is necessary to define the similarities and differences between murine and human hemostasis. After establishing the similarities of murine fibrinogen to human fibrinogen in its pattern of proteolysis in response to plasmin and its cross-linking by factor XIIIa, we studied a new hamster monoclonal antibody (mAb) 7E9 that reacts with the γ chain of mouse fibrinogen. This antibody inhibits platelet adhesion to fibrinogen, platelet-mediated clot retraction, platelet aggregation, and FXIIIa-mediated cross-linking of fibrin; it also facilitates tissue plasminogen activator (tPA)-mediated lysis of fibrin formed either in the absence or presence of platelets. These data provide evidence that the C-terminus of mouse fibrinogen γ chain, like that of human fibrinogen, is involved in fibrinogen binding to platelets and FXIIIa-mediated cross-linking of fibrin. Our data raise the possibility that a therapeutic agent that targets the C-terminus of the γ chain in human fibrinogen might have broad antithrombotic and profibrinolytic effects.
Alterations of Platelet Aggregation Kinetics with Ultraviolet Laser Emission: The “Stunned Platelet” Phenomenon
Authors: Minisi Anthony , Bernardo Nelson , McPherson Richard , Martin Erika , Carr Sheryl , Carr Marcus , Topaz On
Published: March 2018

Platelets, a major constituent of thrombus, play a crucial role in the pathogenesis of acute ischemic coronary syndromes. The effect of ultraviolet laser emission on platelets within thrombi is unknown. The effects of increasing levels of laser energy on platelets in whole blood were investigated. Blood samples were obtained by aseptic venipuncture and anticoagulated with 3.8% sodium citrate. Samples were exposed to increased levels (0, 30, 45, 60 mJ/mm2; 25 Hz) of ultraviolet excimer laser fluence (308 nm wave-length) and then tested for ADP and collagen induced platelet aggregation, platelet concentration, and for platelet contractile force (PCF) development. Scanning electron microscopy was used to detect laser induced morphologic changes of platelets and by flow cytometric analysis to detect changes in expression of platelet surface antigens p-selectin (CD 62) and glycoprotein IIb/IIIa (CD 43). Exposure to excimer laser energy produced dose dependent suppression of platelet aggregation and force development (“stunned platelets”). ADP aggregation decreased from 8.0 ± 1.1 Ohms (mean ± SEM) to 3.7 ± 0.8 Ohms (p 0.001) to 2.7 ± 0.6 Ohms (p 0.001) and to 1.8 ± 0.5 Ohms (p 0.001) as the laser energy increased from 0 to 30 to 45 to 60 mJ/mm2, respectively. Collagen induced aggregation decreased from 21.4 ± 1.4 Ohms to 15.7 ± 1.2 Ohms (p 0.001) to 11.7 ± 1.1 Ohms (p 0.001) and to 9.9 ± 1.0 Ohms (p 0.001), in response to the same incremental range of laser energy. Platelet contractile forces declined from 34,500 ± 3700 to 27,800 ± 2700 dynes as laser energy increased from 0 to 60 mJ/mm2 (p 0.03). Platelet concentration did not change with increasing laser energy. The expression of platelet surface antigen p-selectin (CD 62) remained stable through increasing levels of laser energy exposures while the percentage of CD 43 positive platelets significantly increased with exposure to laser energy, yet the level of expression did not exceed 0.5% of cells. Thus, aggregation kinetics are altered in platelets exposed to ultraviolet laser energy as manifested by decreased platelet aggregation and reduction in platelet force development capability. The response is dose dependent and most pronounced at higher energy levels such as 60 mJ/mm2.