bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Thrombogram: Monitoring Thrombin Generation in Platelet Rich Plasma
Authors: Giesen Peter , Ramjee Manoj , Wagenvoord Rob , Béguin Suzette , Hemker Coenraad 
Published: March 2018

SummaryA method is described in which thrombin activity in clotting plasma can be monitored through the continuous measurement of the fluorescent split-product of the substrate Z-Gly-Gly-Arg-AMC. The signal is not impaired by turbidity; therefore proper measurement is not disturbed by the occurrence of a clot or the presence of platelets and direct measurement in platelet rich plasma is possible.
A Functional Assay Suggests that Heterodimers Exist in Two C-Terminal γ-Chain Dysfibrinogens: Matsumoto I and Vlissingen/Frankfurt IV
Authors: Hogan Kelly , Lord Susan , Okumura Nobuo , Terasawa Fumiko , Galanakis Dennis , Scharrer Inge , Gorkun Oleg 
Published: March 2018

SummaryBecause it contains three pairs of polypeptides, fibrinogen isolated from heterozygous individuals is expected to be a mixture of homodimers and heterodimers. Nevertheless, heterozygous individuals with only homodimers have been identified. We synthesized two recombinant fibrinogens with the mutations from fibrinogen Vlissingen/ Frankfurt IV (γΔ319, 320) and Matsumoto I (γD364H), both identified in heterozygous individuals. We found that polymerization of these fibrinogens was undetectable in 30 min; polymerization of a 1:1 mixture of variant and normal fibrinogen was the same as polymerization of a 1:1 mixture of buffer and normal fibrinogen; polymerization of either plasma fibrinogen was markedly impaired when compared to the 1:1 mixture of the respective variant and normal fibrinogens. We conclude that each plasma fibrinogen is a mix of homodimers and heterodimers, such that the incorporation of heterodimers into the fibrin clot impairs polymerization. We suggest that incorporation of heterodimers can induce clinical symptoms.
In Vivo Penetration of Experimentally Produced Clots by Monoclonal Antibodies
Authors: Edgell T. A. , Webbon P. M. , Gaffney P. J. , McEvoy F. J. 
Published: March 2018

SummaryAntifibrin monoclonal antibodies show potential as clot targeting agents for diagnosis and possibly therapy in thrombotic disease. To be effective the antibody must bind to the fibrin component of the clot. The ability of two antifibrin mabs (NIB 1H10 and NIB 12B3) to penetrate occlusive clots in vivo was investigated Both mabs react with human fibrin but not with human fibrinogen nor with the fibrin or fibrinogen from the species used in this study.Two heterologous animal (sheep and rabbit) thrombus models were used. Clots in both cases were made within isolated vein segments using a mixture of human and native fibrinogen. The clots in sheep veins were observed radiographically and found to be occlusive for a mean of 4.2 ± 2.2 days and thereafter appeared only partially occlusive. When targeted in their occlusive phase 131I labelled mab accumulated in the clot reaching a maximum ratio of 1.82 ± 0.42 when compared to counts in homologous sheep clots in the contralateral limb. It was confirmed in the rabbit jugular vein model that total occlusivity did not prevent antibody accumulation in the heterologous clot by injecting the fibrin specific mab IH10 and examining the clot excised after 1, 6 and 24 h using immunofluorescence. In a further series of similar experiments 125I labelled mab 1H10 was used and detected using autoradiography. Both sets of experiments indicated that penetration of occlusive clots by the antibody occurred and that considerable accumulation was present at 6 and 24 h.The results indicate that a circulating antibody can readily gain access to experimentally produced clots in occluded veins.
Demonstration of an Association between Chlamydia pneumoniae Infection and Venous Thromboembolic Disease
Authors: Lozinguez Olivier , Arnaud Emmanuel , Belec Laurent , Nicaud Viviane , Alhenc-Gelas Martine , Fiessinger Jean-Noël , Aiach Martine , Emmerich Joseph 
Published: March 2018

Summary
Chlamydia pneumoniae infection has been linked to atherosclerosis, but a possible relationship with venous thromboembolism (VTE) has not been sought. We determined circulating anti-C. pneumoniae antibody levels in patients with VTE. We studied 176 case patients with objectively diagnosed VTE and 197 age-and sex-matched healthy controls, in a retrospective study. Acquired risk factors for VTE and frequent predisposing genetic factors (factor V Arg 506 Gln and factor II G 20210 A mutations) were assessed in all the subjects. Anti-C. pneumoniae IgG antibodies were determined by microimmunofluorescence. All positive plasma samples (titer ≥128) were precisely quantified and tested for the presence of specific IgM antibodies. Fiftyfour percent of the cases and 15.9% of the controls had specific IgG titers of at least 256 (p <0.0001). The crude odds ratio for VTE was 6.2 (95% CI, 3.8-10.1), and rose to 7.7 (4.5-13.2) after excluding subjects carrying the factor V Arg 506 Gln or factor II G 20210 A mutations. The odds ratio for VTE increased with the IgG titer: the adjusted odds ratios were 2.1 (95% CI, 1.1-4.1), 5.3 (2.7-10.6) and 33.0 (4.4-248.4) for titers of 256, 512 and 1024, respectively. Only one subject (a case patient) with a high IgG titer (≥256) also had specific IgM. High titers of anti-C. pneumoniae IgG antibodies are frequently found in patients with previous venous thromboembolism. This association deserves to be confirmed in other case-control studies and prospective studies.All authors have reviewed the manuscript and agree with its content.
The Bβ-sheet in the PAI-1 Molecule Plays an Important Role for Its Stability
Authors: Sui Guang-Chao , Wiman Björn 
Published: March 2018

SummaryWe have investigated the B β-sheet in PAI-1 regarding its role for the stability of the molecule. The residues from His219 to Tyr241 (except for Gly230 and Pro240), covering the s2B and s3B strands, and in addition His185 and His190 were substituted by amino acids with opposite properties. The 23 generated single-site changed mutants and also wild type PAI-1 (wtPAI-1) were expressed in E. coli. Subsequently they were purified by heparin-Sepharose and anhydrotrypsin agarose affinity chromatographies. The stability of the purified PAI-1 variants was analyzed at 37° C and at different pHs (5.5, 6.5 or 7.5). At pH 7.5 and 37° C, single substitutions of the residues in the central portions of both strands 2 and 3 in the B β-sheet (Ile223 to Leu226 on s2B and Met235 to Ile237 on s3B), caused a significant decrease in stability, yielding half-lives of about 10–25% as compared to wtPAI-1. On the other hand, mutations at both sides of the central portion of the B β-sheet (Tyr221, Asp222, Tyr228 and Thr232) frequently resulted in an increased PAI-1 stability (up to 7-fold). While wtPAI-1 exhibited prolonged half-lives at pH 6.5 and 5.5, the PAI-1 variant Y228S was more stable at neutral pH (half-life of 9.6 h at pH 7.5) as compared to its half-life at pH 5.5 (1.1 h). One of the 4 modified histidine residues (His229) resulted in a variant with a clearly affected stability as a function of pH, suggesting that it may, at least in part, be of importance for the pH dependence of the PAI-1 stability. Thus, our data demonstrate that the B β-sheet is of great importance for the stability of the molecule. Modifications in this part causes decreased or increased stability in a certain pattern, suggesting effects on the insertion rate of the reactive center loop into the A β-sheet of the molecule.
Homocysteine as a Risk Factor for Restenosis after Coronary Angioplasty
Authors: Kurihara Hiroki , Kuwaki Tomoyuki , Hamada Chikuma , Kitaoka Masao , Suzuki Shin , Yazaki Yoshio , Nagai Ryozo , Morita Hiroyuki 
Published: March 2018

SummaryWe examined the relationship between plasma homocysteine levels and restenosis after PTCA (Percutaneous transluminal coronary angioplasty) to investigate whether plasma homocysteine levels can be a predictor of restenosis after PTCA. One hundred and twelve male patients who have undergone a successful elective PTCA were consecutively enrolled and plasma homocysteine levels were measured at the time of follow-up angiography. Plasma homocysteine levels in patients with restenosis were significantly higher than those in patients without restenosis (15.0 ± 3.9 vs. 13 ± 2.9 µmol/L; P = 0.011). The difference was augmented when diabetic patients were selectively studied. The comparison between restenosis group and non-restenosis group indicated the threshold effect of hyperhomocysteinemia. These results suggest that plasma homocysteine is a potential risk factor of restenosis after PTCA, and therapeutic strategy targeted against hyperhomocysteinemia may be beneficial for preventing restenosis.
The Influence of (R)- and (S)-Warfarin, Vitamin K and Vitamin K Epoxide upon Warfarin Anticoagulation
Authors: Edwards Clive , Butler Timothy , Wynne Hilary , Kamali Farhad 
Published: March 2018

SummaryThe contribution of (R)and (S)-warfarin enantiomers, vitamin K and vitamin K epoxide and patient factors to inter-individual variability in daily warfarin requirements were examined in a group of 73 patients. Simple correlation analysis showed a significant positive relationship between INR values and plasma (S)-warfarin concentrations (r = 0.25; p = 0.038). Multivariate analysis for relationships with INR demonstrated a highly significant positive relationship between INR and (S)- warfarin (p = 0.004) and plasma vitamin K epoxide concentrations (p = 0.028), and a significant negative relationship between INR and plasma vitamin K concentrations (p = 0.034). Twenty five percent of variation in INR could be explained by these variables (adjusted R2 = 0.25). Correlation analysis of data showed that warfarin dosage was significantly and negatively correlated with patient age (r = −0.42; p <0.0001). Patient age accounted for 25% of variation in warfarin dosage requirements (R2 = 0.25). The combined effects of age and vitamin K appear to account for much of the inter-individual variability in warfarin dosage requirements.
Effect of Urinary Protein C Inhibitor on Lipopolysaccharide-induced Disseminated Intravascular Coagulation in Rats
Authors: Izutani Wakako , Komurasaki Yoshikazu , Fujita Mitsugu 
Published: March 2018

SummaryThe effect of urinary protein C inhibitor (uPCI) on disseminated intravascular coagulation (DIC) was investigated using an experimental DIC in rats. uPCI (0.5 and 1.0 mg/kg) was continuously administrated into the left femoral vein of the rats with lipopolysaccharide (50 mg/kg)-induced DIC. In all doses, uPCI significantly prevented the drastic changes in the parameters such as fibrinogen concentration, activated partial thromboplastin time (APTT), prothrombin time (PT), fibrin/fibrinogen degradation products (FDP) level, aspartate aminotransferase (AST) level and alanine aminotransferase (ALT) level. Furthermore, uPCI significantly inhibited the increase in the levels of plasma kallikrein and thrombin which act not only as the procoagulant proteases but also as the chemotactic factors to neutrophils and monocytes. These results show that uPCI may prevent hypercoagulation, the induction of secondary fibrinolysis and organ failure in the DIC model. Therefore, uPCI may be a useful agent for the clinical treatment of DIC.
Fluvastatin Inhibits Basal and Stimulated Plasminogen Activator Inhibitor 1, but Induces Tissue Type Plasminogen Activator in Cultured Human Endothelial Cells
Authors: Mussoni Luciana , Banfi Cristina , Sironi Luigi , Arpaia Magda , Tremoli Elena 
Published: March 2018

SummaryThe effects of fluvastatin, a synthetic hydroxymethylglutaryl coenzyme A (HMG-CoA) inhibitor, on the biosynthesis of tissue plasminogen activator (t-PA) and of its major physiological inhibitor (plasminogen activator inhibitor type 1, PAI-1) were investigated in cultured human umbilical vein endothelial cells (HUVEC). Fluvastatin (0.1 to 2.5 µM), concentration-dependently reduced the release of PAI-1 antigen by unstimulated HUVEC, subsequent to a reduction in PAI-1 steady-state mRNA levels and de novo protein synthesis. In contrast, it increased t-PA secretion.The drug also reduced PAI-1 antigen secreted in response to 10 µg/ml bacterial lipopolysaccharide (LPS), 100 U/ml tumour necrosis factor α (TNFα) or 0.1 µM phorbol myristate acetate (PMA).Mevalonate (100 µM), a precursor of isoprenoids, added to cells simultaneously with fluvastatin, suppressed the effect of the drug on PAI-1 both in unstimulated and stimulated cells as well as on t-PA antigen. Among intermediates of the isoprenoid pathway, all-trans-geranylgeraniol (5 µM) but not farnesol (10 µM) prevented the effect of 2.5 µM fluvastatin on PAI-1 antigen, which suggests that the former intermediate of the isoprenoid synthesis is responsible for the observed effects.
Assessment of Primary Hemostasis by PFA-100® Analysis in a Tertiary Care Center
Authors: James Andra , Thames Elizabeth , Moore Karen , Greenberg Charles , Ortel Thomas 
Published: March 2018

SummaryWe evaluated the utility of the PFA-100® platelet function analyzer in identifying disorders in platelet function and/or von Willebrand factor (vWF) in patients with various systemic disorders being followed at a tertiary care center. Closure times were determined with collagen/ ADP (CADP) and collagen/epinephrine (CEPI) cartridges for 305 patients, and abnormal results were further evaluated with platelet aggregometry and vWF analysis. Prolonged CADP and/or CEPI closure times were identified in 114 patients (37.3%), but most were isolated prolonged CEPI closure times predominantly due to aspirin therapy (79 patients). Prolonged CADP closure times were most frequently due to qualitative platelet defects and/or decreased vWF levels. Prolonged CADP closure times were encountered most frequently in patients with sickle cell disease and were associated with a decreased hematocrit. This study demonstrated that the PFA-100® analyzer can accurately assess vWF-dependent platelet function and detect other platelet defects under high shear stress in complex patient populations.
A Collaborative Study to Establish the 2nd International Standard for Fibrinogen, Plasma
Authors: Whitton C. M. , Sands D. , Gaffney P. J. , Hubbard A. R. 
Published: March 2018

SummaryAn International Collaborative Study involving 12 laboratories in 7 different countries was undertaken in order to replace the 1st International Standard (IS) for Fibrinogen, Plasma (89/644). The candidate replacement standard was the ampouled and freeze-dried residue of solvent/detergent treated plasma and was calibrated as coded duplicates (A and B) versus the 1st IS Fibrinogen, Plasma by automated Clauss assay and by a recommended clot collection (gravimetric) assay. This latter method had been used to calibrate the 1st IS Fibrinogen, Plasma.Comparing the ratios of the potency estimates of sample A to sample B (the coded duplicates), all of the laboratories obtained a ratio within 5% of the expected value of 1.0 by automated Clauss assay, which suggests that the laboratories were able to perform this assay well. Scrutiny of the data obtained from the gravimetric assays revealed that in almost all cases the results were invalid. The results of these assays are included in this report but clearly should be treated with caution and indeed produced significantly lower mean estimates of potency than the other assay methods. The overall geometric mean of all estimates of potency of the proposed 2nd IS Fibrinogen, Plasma (98/612) is 2.19 mg/ampoule by the automated Clauss assay. These data have been presented to the Fibrinogen Sub-Committee of the Standardisation and Scientific Committee (SSC) of the International Society on Thrombosis and Haemostasis (ISTH) (Washington, DC, August 1999), which recommended the establishment of 98/612 as the 2nd IS Fibrinogen, Plasma. This report has been presented to the Expert Committee on Biological Standardisation of the World Health Organisation (ECBS-WHO) at their 1999 session and 98/612 was established as the 2nd IS Fibrinogen, Plasma with a potency of 2.2 mg/ ampoule.
Endothelial Cell Seeding on Crosslinked Collagen: Effects of Crosslinking on Endothelial Cell Proliferation and Functional Parameters
Authors: Wissink M. J. B. , van Luyn M. J. A. , Beernink R. , Dijk F. , Poot A. A. , Engbers G. H. M. , Beugeling T. , van Aken W. G. , Feijen J. 
Published: March 2018

SummaryEndothelial cell seeding, a promising method to improve the performance of small-diameter vascular grafts, requires a suitable substrate, such as crosslinked collagen. Commonly used crosslinking agents such as glutaraldehyde and formaldehyde cause, however, cytotoxic reactions and thereby hamper endothelialization of currently available collagen-coated vascular graft materials.The aim of this study was to investigate the effects of an alternative method for crosslinking of collagen, using N-(3-dimethylaminopropyl)-N’-ethylcarbodiimide (EDC) in combination with N-hydroxysuccinimide (NHS), on various cellular functions of human umbilical vein endothelial cells (HUVECs) in vitro. Compared to non-crosslinked type I collagen, proliferation of seeded endothelial cells was significantly increased on EDC/NHS-crosslinked collagen. Furthermore, higher cell numbers were found with increasing crosslink densities. Neither the morphology of the cells nor the secretion of prostacyclin (PGI2), von Willebrand factor (vWF), tissue plasminogen activator (t-PA) and plasminogen activator inhibitor (PAI-1) was affected by the crosslink density of the collagen substrate. Therefore, EDC/NHScrosslinked collagen is candidate substrate for in vivo application such as endothelial cell seeding of collagen-coated vascular grafts.
Deficiency Causing Mutations and Common Polymorphisms in the Factor XIII-A Gene
Authors: Muszbek L. 
Published: March 2018

SummaryBlood coagulation factor XIII (FXIII), for its unique features, used to be considered a stepchild among clotting factors. In contrast to other proenzyme clotting factors, it is the precursor of a transglutaminase and not of a proteolytic enzyme. By cross-linking peptide-bound glutamine and lysine side chains transglutaminases make, rather than break, peptide bonds. Activated FXIII (FXIIIa) cross-links fibrin α-chains and γ-chains and covalently attaches α2-plasmin inhibitor to fibrin α-chains to strengthen fibrin mechanically and to protect it from fibrinolysis. In addition to being a clotting factor, FXIII is also an intracellular proenzyme present in platelets and monocytes/macrophages. The plasma factor is of heterotetrameric structure consisting of two potentially active A (FXIII-A) and two inhibitory/protective B (FXIII-B) subunits (A2B2), while its cellular counterpart is a dimer of FXIII-A. Plasma FXIII is activated by the concerted action of thrombin and Ca2+. Thrombin cleaves FXIII-A at Arg37-Gly38, then in the presence of Ca2+ FXIII-B dissociates and FXIII-A assumes an active configuration (reviewed in ref. 1).
Low Molecular Weight Heparin (Enoxaparin) Versus Oral Anticoagulant Therapy (Acenocoumarol) in the Long-Term Treatment of Deep Venous Thrombosis in the Elderly: a Randomized Trial
Authors: Escribá A. , Maluenda M. P. , Rubio M. , Margalet I. , Lezana A. , Gallego J. , Ribera J. M. , Veiga F. 
Published: March 2018

SummaryThis study aims to establish the relative effectiveness and safety of low molecular weight heparin in elderly patients with venous thrombosis in order to find an alternative to oral anticoagulant therapy with less bleeding complications in the long-term treatment of deep venous thrombosis (DVT).One hundred consecutive elderly patients (>75 years old) with venographically demonstrated proximal DVT were included in a randomized trial. All patients were treated for ten days with adjusted doses of intravenous heparin. Informed consent was obtained and on the eight day, patients were randomly allocated to receive acenocoumarol (INR 2.0-3.0) or subcutaneous enoxaparin (4000 anti-Xa units once a day) for three months. All patients were followed-up clinically and venographically for a one year period. The results were analyzed with Fisher’s exact test or chi-square test as appropriate.During the treatment and surveillance period, 6 of the 50 patients (12%) who received acenocoumarol and 8 of the 50 patients (16%) who received enoxaparin had new episodes of venous thromboembolism confirmed by objective testing (p = 0.6; 95% CI for the difference: −19.5 to 11.5). Hemorrhagic complications occurred in six of the 50 patients (12%) who received acenocoumarol and in one (2%) of those on enoxaparin (p = 0.1; 95% CI for the difference: -1.8 to 21.8). Vertebral fractures developed in 2 patients (4%) in the enoxaparin group (p = 0.5; 95% CI for the diference: −11.4 to 3.4).These results show that fixed dose enoxaparin seems to be effective and safe in the long-term treatment of proximal DVT in the elderly. In comparison with oral anticoagulants, the findings are inconclusive due to the wide confidence intervals for differences between outcomes, however they suggest that the former may have less bleeding complications with similar efficacy.
Increased Fibrinogen Levels and Hemostatic Abnormalities in Patients with Arteriolar Nephrosclerosis: Association with Cardiovascular Events
Authors: Zingaro Laura , Catena Cristiana , De Marchi Sergio , Sechi Leonardo 
Published: March 2018

SummaryIncreased plasma fibrinogen levels and hemostatic abnormalities suggestive of a prothrombotic state are present in patients with endstage renal failure and could contribute to increased cardiovascular morbidity in these patients. We investigated the relationship between abnormalities of the hemostatic system and the degree of renal failure and whether these abnormalities are associated with increased prevalence of cardiovascular events in patients with arteriolar nephrosclerosis. In 425 patients recruited at a hypertension clinic we assessed the renal function by creatinine clearance, urinary protein excretion, and microalbuminuria, the prevalence of atherosclerotic disease, and measured prothrombin time, activated partial thromboplastin time, fibrinogen, prothrombin fragment 1+2 (F1+2), D-dimer, and antithrombin. Early impairment of renal function (creatinine clearance, 30 to 89 ml/min per 1.73 m2 of body surface area) caused by arteriolar nephrosclerosis was found in 172 patients. Patients with early renal failure were significanly older and had significantly greater values of blood pressure, plasma fibrinogen, F1+2, and D-dimer than patients with normal renal function. Elevated D-dimer and fibrinogen levels were independently associated with the presence of decreased creatinine clearance. Log fibrinogen, log F1+2, and log D-dimer were inversely correlated with creatinine clearance. The prevalence of coronary artery, cerebrovascular, and peripheral vascular disease was significantly greater in patients with mild renal failure than in those with normal renal function. Elevated levels of fibrinogen and D-dimer were associated with the presence of atherosclerotic disease independent of renal function and other risk factors. In conclusion, changes in hemostatic parameters occur early in the course of renal failure in patients with arteriolar nephrosclerosis, suggesting a prothrombotic state that may contribute to the risk for atherosclerotic disease at all levels of renal function.