bluuebunny/crossref_metadata_2025_split huggingface dataset:
Short-term Effect of Surgical Trauma on Rat Peritoneal Fibrinolytic Activity and Its Role in Adhesion Formation
Authors: Trimbos-Kemper G. C. M. , Bakkum E. A. , Trimbos J. B. M. Z. , Declerck P. J. , Kooistra T. , Emeis J. J. , Hellebrekers B. W. J. 
Published: March 2018

SummaryFibrin deposition, the primary step in the formation of post-surgical adhesions, is the result of a disbalance between the fibrinforming and the fibrin-dissolving capacity of the peritoneum. Literature data suggest a transient reduction in local plasminogen activator activity after peritoneal trauma, which results in a reduction of fibrinolysis and permits deposited fibrin to become organized into fibrous, permanent adhesions. In the present study, the fibrinolytic parameters tissue-type plasminogen activator (tPA; antigen and activity) and plasminogen activator inhibitor type-1 (PAI-1; antigen and activity) were measured in peritoneal fluid, in peritoneal biopsies and in plasma to establish the time course of changes in fibrinolytic activity.A standardized peritoneal adhesion model in the rat.Analysis, over a 72-h period following surgical trauma, of the main fibrinolytic parameters in peritoneal lavage, in biopsies of damaged and undamaged peritoneum, and in plasma, and determination of fibrin and fibrin(ogen)-degradation products in peritoneal lavage fluid.At all time intervals, tPA antigen was found to be about six-fold increased in peritoneal lavage after surgical trauma. This significant rise in tPA antigen was accompanied by a large increase in its main inhibitor PAI-1, resulting in tPA activity levels similar to, or slightly higher than, those found in control animals. tPA activity was lowest at 4 h and increased thereafter. Also in biopsies from damaged peritoneum, tPA antigen was significantly increased. Tissue tPA activity was also lowest at 4 h, after which it increased, significantly so at 24 and 72 h. Similar, though smaller, changes were seen in the biopsies from undamaged areas of the peritoneal wall in operated rats. PAI-1 (antigen and activity) was not detected in peritoneal biopsies. Fibrin-related material (especially fibrin monomer/fibrinogen, an indicator of forming fibrin) in peritoneal fluid was slightly increased at 4 h, and abundantly present at 16 and 24 h, returning to control levels at 72 h. Fibrin degradation products were always present. From 2 h onward, adhesions were found.In contrast to the view that adhesions are formed as a result of a reduced fibrinolytic activity, our results demonstrate that tPA activity remained unchanged or slightly increased after surgical trauma, and point to increased fibrin formation rather than diminished fibrinolytic activity as the main cause of fibrin deposition after peritoneal trauma. Therapies directed at prevention of adhesion formation should therefore aim at avoiding massive fibrin production and at promoting fibrinolytic activity during the early period after trauma.
S-Nitrosoderivative of a Recombinant Fragment of von Willebrand Factor (S-Nitroso-AR545C) Inhibits Thrombus Formation in Guinea Pig Carotid Artery Thrombosis Model
Authors: Gurevitz Osnat , Eldar Michael , Skutelsky Ehud , Tamarin Ilia , Shenkman Boris , Eskaraev Regina , Castel David , Loscalzo Joseph , Inbal Aida 
Published: March 2018

SummaryAntiplatelet drugs are the mainstays of therapy for acute and chronic cardiovascular diseases. S-nitroso-AR545C – an S-nitrosoderivative of a recombinant von Willebrand factor fragment AR545C spanning Ala 444 to Asp 730 and containing an Arg 545 Cys mutation, was previously found to inhibit ristocetin-and ADP-induced platelet aggregation and the interaction of platelets with extracellular matrix (ECM). In the current study we tested the antithrombotic properties of S-nitroso-AR545C on guinea pig platelets and in a platelet-rich thrombosis model in the guinea pig. Preincubation of guinea pig platelets with 0.1 µM of S-nitroso-AR545C decreased ristocetin-induced agglutination by 40% (p = 0.009) and completely abolished ADP-induced aggregation (p <0.0001). At concentration of 1.0 µM, S-nitroso-AR545C completely inhibited platelet adhesion (represented by surface coverage – SC) and decreased aggregate formation (represented by average aggregate size – AS) by more than 50%. Treatment of guinea pigs with 1.0 mg/kg S-nitroso-AR545C resulted in a significantly delayed time to arterial occlusion (31.7 ± 6.0 min vs. 13.9 ± 3.2 min, p <0.02). Similarly, total patency time was longer in the group injected with S-nitroso-AR545C compared to the control group. However, the difference was not statistically significant (33.8 ± 6.3 min vs. 20.2 ± 3.3 min, p = 0.07). No change in platelet count, hematocrit and bleeding time was observed 60 min after injection compared to baseline. In contrast, a significant decrease in SC (p <0.0001) and AS (p <0.01) were observed 60 min after the injection of S-nitroso-AR545C, whereas no change in these parameters was observed in the control group. These observations indicate that S-nitroso-AR545C exhibits significant antiadhesive and antiaggregating effects in-vitro and inhibits clot formation in-vivo suggesting that this compound may have potential therapeutic advantages.
The 536C→T Transition in the Human Tissue Factor Pathway Inhibitor (TFPI) Gene Is Statistically Associated with a Higher Risk for Venous Thrombosis
Authors: Schmidt Michael , Götting Christian , Schwenz Britt , Lange Stefan , Müller-Berghaus Gert , Brinkmann Thomas , Prohaska Wolfgang , Kleesiek Knut 
Published: March 2018

SummaryTissue factor pathway inhibitor (TFPI) is an important regulator in the extrinsic blood coagulation pathway. Although the regulatory biochemical role of TFPI is evident, the clinical significance of this proteinase inhibitor remains to be elucidated. The definition of a clinical TFPI deficiency seems to be more complex than that of other coagulation inhibitors because the activity and concentration of circulating TFPI can not be considered a true measure of in vivo levels. Its determination in plasma samples by immunological methods or functional assays has been shown to be inadequate in the detection of a clinical deficiency.Therefore, we screened genomic DNA samples of blood donors and thrombotic patients for alterations in the TFPI gene to assess the influence of a modified TFPI in venous thromboembolic diseases. We detected a single nucleotide substitution in exon 7 (536C→T) leading to a proline to leucine exchange at amino acid position 151 of the protein ([P151L]TFPI) and found the prevalence of heterozygous carriers in German unrelated blood donors to be 0.2% (n = 5120).Four unrelated persons out of 14 probands carrying the genetic variation could be linked to venous thrombosis. For calculation of a potential risk for venous thrombosis for carriers of the mutation we investigated healthy blood donors about thrombotic events. 7 out of 308 blood donors were found to have a history of venous thrombosis, one of them carried the TFPI mutation. Statistical calculation showed a significant relative risk for venous thrombosis for individuals with the trait (odds ratio, 9.3; confidence interval, 1.8-48.6; p <0.01).
Genetic Polymorphism of 5,10-MTHFR Reductase Gene in Offspring of Patients with Myocardial Infarction
Authors: Colaizzo Donatella , Cappucci Giuseppe , del Popolo Annamaria , Vecchione Gennaro , Grandone Elvira , Di Minno Giovanni , Margaglione Maurizio 
Published: March 2018

SummaryA family history of myocardial infarction is a major determinant of ischemic disease. A C->T677 polymorphism in the methylenetetrahydrofolate reductase (MTHFR) gene has been identified as a cause of mild hyperhomocysteinemia, a risk factor for arterial thrombosis. We have investigated the relationship between the MTHFR TT genotype and a family history of myocardial infarction in a cohort of 982 apparently healthy individuals. Subjects whose first-degree relatives suffered from a myocardial infarction, showed raised median age (p <0.001), total cholesterol (p <0.001) and plasma fibrinogen (p = 0.023) and a higher than normal frequency of C-reactive protein levels >0.33 mg/dl (p = 0.012). Moreover, when compared to subjects without such family history, a higher number of homozygotes for the T allele of the MTHFR gene (p = 0.027), and of the 4G allele of the plasminogen activator inhibitor-1 gene (p = 0.002) was found in the subsetting of the offspring of patients with myocardial infarction. In a multiple logistic regression analysis, age (OR 1.02 [95%-CI: 1.00-1.05]), total cholesterol (OR 1.40 [95%-CI: 1.14-1.71]), C-reactive protein levels >0.33 mg/l (OR: 1.87 [95%-CI: 1.10-3.20]), plasminogen activator inhibitor-1 4G/4G (OR: 1.84 [95%-CI: 1.27-2.66]), and MTHFR TT genotype (OR 1.62 [95%-CI: 1.08-2.42]), were all associated with a family history of myocardial infarction. Thus, the MTHFR TT genotype independently accounts for the risk of a family history for myocardial infarction in the present setting.
Evaluation of the PFA-100® System in the Diagnosis and Therapeutic Monitoring of Patients with von Willebrand Disease
Authors: Federici Augusto , Lecchi Anna , Agati Barbara , Lombardi Rossana , Stabile Federica , Bucciarelli Paolo , Cattaneo Marco 
Published: March 2018

SummaryWe have evaluated platelet function at high shear with the PFA-100® system in different subtypes of von Willebrand disease (vWD), before and after the intravenous infusions of desmopressin or a factor-VIII/von Willebrand factor (vWF) concentrate. Closure times with the PFA-100® system were determined for both the collagen/ADP and the collagen/epinephrine cartridges in 52 patients with vWD (9 type 1 “platelet normal”, 5 type 1 “platelet-discordant”, 8 type 1 “platelet-low”, 6 type 2A, 9 type 2B, 6 type 2M Vicenza, 6 type 3 and 3 acquired vWD) and 40 controls. Measurements were repeated 1 and 4 h after the i.v. infusion of desmopressin (0.3 μg/Kg) in 26 patients with types 1, type 2M Vicenza or type 2A vWD, or of a factorVIII/vWF concentrate (Alphanate HT, 60 U/Kg) in 4 patients with type 3 vWD. At all time points, vWF plasma levels and the bleeding time (Symplate II) were also determined. Baseline closure times were longer in vWD patients than in controls with both the collagen/ADP and the collagen/ epinephrine cartridges. The sensitivity of the PFA-100® system (88% and 87% with the two cartridges) was higher than that of the bleeding time (65%). Treatment with desmopressin normalized the closure times in patients with type 1 “platelet-normal” or type 2M Vicenza vWD, had no significant effects in patients with type 1 “platelet-low”, type 1 “platelet-discordant” or type 2A vWD. Infusion of a factorVIII/vWF concentrate in patients with type 3 vWD slightly shortened their prolonged closure times. In general, changes in PFA-100® were paralleled by shortenings of the bleeding times and increases in plasma vWF levels. The PFA-100® test reflects vWF-dependent platelet function under high shear stress and could be useful in the diagnosis and therapeutic monitoring of patients with vWD.
Antithrombogenic Coating of Stents Using a Biodegradable Drug Delivery Technology
Authors: Herrmann R. , Schmidmaier G. , Märkl B. , Resch A. , Hähnel I. , Stemberger A. , Alt E. 
Published: March 2018

SummaryTo reduce the thrombogenic properties of coronary artery stents, a biodegradable polylactic acid (PLA) stent coating with an incorporated thrombin inhibitor and a platelet aggregation inhibitor has been developed. In an ex vivo human stasis model, its effect on platelets, plasmatic coagulation and its release characteristics were studied using whole blood. Bare steel and bare gold-surface stents were compared to steel and gold-surface stents coated with PLA (30 kDa) containing 5% polyethyleneglycol (PEG)-hirudin and 1% iloprost, with an empty tube as control. Markers of activated coagulation (prothrombin fragment F1-2 and thrombin-antithrombin III complex, TAT), were assayed and the release of drugs from the coating was assessed by aPTT and collagen-induced platelet aggregation. Bare steel and gold stents were completely covered by a blood clot, and high levels of coagulation markers (F1-2 fragment and TAT) were detected. No differences in the thrombogenic properties were found between bare gold or steel stents. Coated stents were free of blood clots and only minor elevations of markers were detected. Release data from in-vitro studies over 90 days showed a gradual release of the drugs with an initial exponential release characteristic for PEG-hirudin, slow release of iloprost and a 10% degradation of the PLA carrier. This drug releasing biodegradable coating effectively reduced thrombus formation independent of the metallic surface.
Adsorption of Vitamin K-dependent Proteins to Live Cell Membranes Measured under Flow Conditions
Authors: Teuschler Hoa , McGee Maria 
Published: March 2018

SummaryMechanisms mediating initial adsorption of coagulation proteins to live cells were investigated. Adsorption kinetics were examined under varying flow conditions using tracer-dilution techniques in perfused spherical monolayers of cells expressing tissue factor. At biologically relevant time and concentration ranges, rates exceeded by 2-12 fold the theoretical maximum calculated for steady-state diffusion. Rates were correlated with aqueous-phase flux of reactants and were found to be largely independent of the density of reactive sites on the membrane. Average adsorption rate of factor VIIa at 4 ηM and flow velocity of 0.8 ηm s-1 was 5 × 107 s-1 cm-2. Adsorption rates of homologous coagulation factors IX and X under similar conditions were 5 and 9 × 107 s-1 cm-2. Results indicate that flow can effectively increase the rate of coagulation factor adsorption to the membrane of live cells. They also imply that factors affecting blood flow velocity and vessel permeability influence the rate of membrane-dependent coagulation reactions.
New Assay for Measuring Binding of Platelet Glycoprotein IIb/IIIa to Unpurified von Willebrand Factor
Authors: Veyradier Agnès , Jumilly Anne-Lise , Ribba Anne-Sophie , Obert Bernadette , Houllier Anne , Meyer Dominique , Girma Jean-Pierre 
Published: March 2018

SummaryAmong the numerous variants of vWD, no patient with an abnormal vWF binding to GPIIb/IIIa has been described to date. To search for such potential variants, we developed a two-site assay for measuring the binding of purified GPIIb/IIIa to vWF in biological fluids and we used it to study a large series of plasmas from various types of von Willebrand disease (vWD) and recombinant vWF (rvWF).vWF in plasma or rvWF in culture medium was immobilized onto anti-vWF monoclonal antibodies (MoAb)-coated wells of microtiter plates. After incubation with either unlabeled GPIIb/IIIa and a 125I-anti-GPIIb/IIIa MoAb or 125I-GPIIb/IIIa, binding curves and binding isotherms were respectively established. Normal pool plasma and wild-type rvWF were used as reference samples. We tested plasmas from 85 normal subjects, 115 patients with different types of vWD (64 type 1, 2 type 3, 9 type 2A, 4 type 2M, 16 type 2B, 15 type 2N, 3 type IID and 2 acquired forms) and 50 patients with various bleeding disorders. Four mutated rvWF with 2A (Glu875Lys and Pro885Ser) or 2B (Dupl.Met540 and Val551Phe) substitutions and one rvWF mutated in the RGD domain of the C-terminal part of vWF-subunit (Asp1746Gly) were also studied.Among the various samples tested, only rvWF Asp1746Gly had no affinity for GPIIb/IIIa. In contrast, GPIIb/IIIa similarly bound to the other vWF, independently of the proteic environment, the factor VIII level, the degree of multimerization or the mutation of vWF. Our results indicate that subjects with an abnormal vWF binding to GPIIb/IIIa are probably rare and difficult to target for a specific screening.
Increased Levels of Tissue Factor mRNA in Mononuclear Blood Cells of Patients with Primary Antiphospholipid Syndrome
Authors: López-Pedrera Chari , Velasco Francisco , Aguirre María , Torres Antonio , Cuadrado María , Dobado-Berrios Pablo 
Published: March 2018

SummaryAntiphospholipid antibodies (aPL) may stimulate tissue factor (TF) expression in cultured endothelial cells and monocytes, but there are discrepancies as to the expression of TF in the patients with antiphospholipid syndrome (APS). By using reverse transcription and polymerase chain reaction amplification, we have analysed TF mRNA accumulation in freshly isolated mononuclear blood cells (MBC) of 14 patients with primary APS (PAPS) and six normal controls. TF mRNA accumulation was low or absent in uncultured MBC from all normal controls, but was elevated in uncultured MBC from nine of the patients as well as in normal MBC incubated with 100 ng/ml lipopolysaccharide (LPS). Mean levels of TF mRNA, as measured by densitometry, were higher in MBC from patients (N = 14) than in those from controls (N = 6, P = 0.009), and in MBC from patients with a history of thrombosis (N = 9) than in those from patients without thrombosis (N = 5, P = 0.02). Uncultured MBC of patients with thrombosis accumulated TF mRNA at similar levels to LPS-treated normal MBC. Increased levels of TF mRNA were found in eight of ten patients with conventional aPL (ie, anti-cardiolipin antibodies [aCL] and/or lupus anticoagulant [LA]) and littleif any accumulation of TF mRNA was observed in three of four patients without aPL at the time of study. These data strongly suggest that circulating monocytes of many patients with PAPS are subjected to an up-regulated TF expression that may well explain their prothrombotic state. Although the presence or absence of TF mRNA in MBC was associated with, respectively, the presence or absence of conventional aPL in 11 of the 14 patients studied, our study cannot exclude the involvement of factors other than aCL or LA in inducing TF expression.
Multicenter, Randomized, Comparative Study of Recombinant vs. Natural Streptokinases in Acute Myocardial Infarct (TERIMA)
Authors:   The TERIMA Group Investigators
Published: March 2018

Summary
Aim: To compare the effects on hemostasis and coronary patency of recombinant (rSK) and natural (nSK) streptokinases in patients with acute myocardial infarct (AMI). Methods: Patients from 7 hospitals, <70 years old, less than 12 h after the onset of AMI symptoms, with ST segment elevation or bundle branch block, without contraindications for thrombolytic therapy, were randomized to receive 1.5 million units of nSK or rSK in a one-hour intravenous infusion. Fibrinogen, fibrinogen degradation products (FDP) and thrombin time were monitored. A coronary angiography was performed after 5-10 days in those patients who gave their consent and did not refer allergy to iodine contrasts. Images were blindly evaluated by an independent committee. Results: 224 patients were randomized (113 nSK and 111 rSK). Groups were equivalent in all baseline and demographic variables except that rSK patients were 5.4 years significantly older. They were also comparable in all the clinical characteristics. Both treatments produced the same changes in hemostasis. Fibrinogen levels decreased, FDP and thrombin time increased immediately after thrombolysis and returned to baseline 2 days afterwards, but fibrinogen values continued to increase up to day 10. Coronary patency (TIMI 2-3) rates at 7.8 ± 2.7 and 8.0 ± 2.7 days after fibrinolysis were 70.7% and 67.1% for nSK and rSK groups, respectively (non-significant difference). Hypotension and arrhythmias were the most frequent adverse events in both groups, which did not differ in this respect either. Five patients from each group died, one of them (nSK) due to gastroduodenal bleeding probably related to treatment. Conclusions: rSK behaved similarly to nSK regarding coronary patency at 8 days after thrombolysis and the changes induced on fibrinogen, FDP and thrombin time. These results suggest that the same benefit/risk profile reported for AMI patients treated with nSK can be expected for rSK.A list of the “Trombolisis con Estreptoquinasa Recombinante en el Infarto del Miocardio Agudo” (Thrombolysis with Recombinant Streptokinase in Acute Myocardial Infarct) investigators appears in the Appendix, p. 1608.
Monocyte Tissue Factor Expression Is Enhanced in Women who Smoke and Use Oral Contraceptives
Authors: Terhalle Helma-Meta , Zakel Ute , Maus Ulrich , Parviz Behnoush , Tillmanns Harald , Haberbosch Werner , Hölschermann Hans 
Published: March 2018

SummaryThe association between use of oral contraceptives (OCs) and increased risk of thromboembolic disease has been firmly established. This risk increases when use of OCs is combined with cigarette smoking. The cellular mechanism favoring an hypercoagulable state under these behaviours is not known. Circulating monocytes are potent activators of the coagulation cascade through their ability to synthesize procoagulant tissue factor (TF). In the present study we report that monocyte TF expression is increased in women who use OCs and smoke.We studied monocyte TF expression in 4 groups of healthy pre-menopausal women (n = 15 each): (1) non-smoking OC non-users, (2) nonsmoking current OC users, (3) smoking OC non-users and (4) smoking OC users. TF expression was assessed on both mRNA and protein levels in unstimulated and LPS-stimulated cells. Transcriptional activation of the TF gene was assessed by analysis of the transcription factor NF-κB and its inhibitor molecule IκBα. Monocyte TF generation was significantly higher in OC users than in women who did not use OCs. Enhanced monocyte TF generation was also observed in smoking women when compared to non-smokers. Strongest monocyte TF expression occurred in women with combined smoking and use of OCs. The enhanced TF expression in monocytes from women using OCs or smoking was based on an increased TF gene transcription following activation of NF-κB. Experiments on cultured monocytes/macrophages demonstrated enhanced IκBα degradation in the presence of estradiol, suggesting that a direct hormone effect is responsible for the observed increase in monocyte TF expression.This study demonstrates that use of OCs and smoking is associated with an increase in monocyte TF expression in pre-menopausal women. Aberrant TF expression by blood monocytes may favour intravascular clotting activation in women with OC therapy. The further enhancement of TF activity observed in women who smoke and use OCs may explain the synergistic effect of smoking on risk of thromboembolic events associated with contraceptive use.