bluuebunny/crossref_metadata_2025_split huggingface dataset:
Significant Correlations between Tissue Factor and Thrombin Markers in Trauma and Septic Patients with Disseminated Intravascular Coagulation
Authors: Nanzaki Satoshi , Sasaki Shigeyuki , Kemmotsu Osamu , Gando Satoshi 
Published: March 2018

SummaryTo determine the role of plasma tissue factor on disseminated intravascular coagulation (DIC) in trauma and septic patients, and also to investigate the relationships between tissue factor and various thrombin markers, we made a prospective cohort study. Forty trauma patients and 20 patients with sepsis were classified into subgroups according to the complication of DIC. Plasma tissue factor antigen concentration (tissue factor), prothrombin fragment F1+2 (PF1+2), thrombin antithrombin complex (TAT), fibrinopeptide A (FPA), and D-dimer were measured on the day of admission (day 0), and on days 1, 2, 3, and 4 after admission. The levels of plasma tissue factor in the DIC group were more elevated than those of the non-DIC group in both the trauma and the septic patients. In patients with sepsis, tissue factor levels on days 0 through 4 in the non-DIC group showed markedly higher values than those in the control patients (135 ± 8 pg/ml). Significant correlations between tissue factor and PF1+2, TAT, FPA, and D-dimer were observed in the DIC patients, however, no such correlations were found in the non-DIC patients. These results suggest that elevated plasma tissue factor in patients with trauma and sepsis gives rise to thrombin generation, followed by intravascular coagulation.
Characterization of a Factor VII Molecule Carrying a Mutation in the Second Epidermal Growth Factor-like Domain
Authors: Kavlie Anita , Örning Lars , Grindflek Anne , Stormorken Helge , Prydz Hans 
Published: March 2018

SummaryA missense mutation at codon 100 in the second epidermal growth factor-like domain, resulting in Gln100→Arg, was detected in 19 out of 21 available severely factor VII (FVII) deficient patients in Norway. Seventeen patients were homozygous, and the two remaining were compound heterozygotes. In the homozygous patients, FVII antigen was measured to 10-28%, and activity to 0.6-6.5% of that in normal pooled plasma. Recombinant FVII containing the mutation was expressed transiently in CHO cells to a mean antigen level of 57% of the wild type FVII protein, and with a specific activity of 6% of wild type. The mutant protein had a 14-fold reduction in affinity for tissue factor (TF), whereas binding of FX seemed unaffected. In line with the experimental data, molecular modelling of the mutation based on the coordinates of the tissue factor/FVIIa complex showed that substituting arginine for glutamine disrupts the interface between the catalytic and second epidermal growth factor-like domains.
New Splicing Mutations in the Human Factor XIIIA Gene, Each Producing Multiple Mutant Transcripts of Varying Abundance
Authors: Miloszewski Krzysztof , Markham Alexander , Anwar Rashida 
Published: March 2018

SummaryCoagulation factor XIII, a transglutaminase which stabilises blood clots by covalently cross-linking fibrin, is essential for normal haemostasis. FXIII deficiency results in a life-long bleeding disorder with added complications in wound healing and tissue repair. Sequence changes in the human FXIIIA gene, largely missense mutations, are primarily responsible for inherited FXIII deficiency. We have carried out molecular analysis of the FXIIIA gene in two unrelated FXIII deficient individuals and identified three splice site mutations; a g→a at the exon 6 acceptor splice site, a g→a at the exon 7 donor splice site and a coding sequence T→G at the exon 8 donor splice site. We have also examined the FXIIIA mRNA in these patients and find that each mutation gives rise to multiple transcripts which vary in their relative abundance. The precise molecular mechanisms which result in these variant transcripts, and their relative abundance in our FXIII deficient patients, are discussed.
Nitric Oxide and Prostacyclin Are Involved in Antithrombotic Action of Captopril in Venous Thrombosis in Rats
Authors: Chabielska Ewa , Golatowski Janusz , Azzadin Arsalan , Buczko Włodzimierz , Pawlak Robert 
Published: March 2018

SummaryThe long-term administration of captopril to patients with a left ventricular dysfunction after myocardial infarction reduces the rate of recurrent coronary thrombosis. Thus, in the present study we investigated the influence of angiotensin-converting enzyme inhibitors (ACE-Is) on experimental venous thrombosis in normotensive rats and the involvement of NO and PGI2 in this effect. Animals were treated with captopril (1.5, 5 or 25 mg/kg twice daily, CAP), enalapril (15 mg/kg once daily, ENA) or distilled water for 10 days, per os. After ligation of the vena cava the thrombus weight decreased in both CAP and ENA treated rats. The effect was most pronounced in animals given the highest dose of CAP (p<0.0001 vs. control) and was significantly stronger than observed in ENA treated animals (CAP vs. ENA p<0.01). The mean blood pressure measured by the “tail cuff” method and platelet aggregation were not altered by either of the ACE-Is. The antithrombotic activity of CAP was reduced by indomethacin (2.5 mg/kg, s.c.) and independently by the NO-synthase inhibitor NG-nitro L-arginine methyl ester (3 mg/kg i.v. bolus + 3 mg/kg/h i.v. infusion, L-NAME). In the latter case CAP regained its antithrombotic properties in rats pretreated with L-Arginine (300 mg/kg i.v. + 300 mg/kg/h i.v.) before administration of L-NAME (p<0.05 vs. control). Moreover, the concomitant administration of indomethacin and L-NAME failed to completely abolish the antithrombotic action of captopril. Similar effects were observed in respect to the incidence of venous thrombosis. Our study documents a novel and important effect of ACE-Is on the vein thrombotic process and demonstrates the involvement of NO and PGI2 in this phenomenon.
Factor XI and Protection of the Fibrin Clot against Lysis – a Role for the Intrinsic Pathway of Coagulation in Fibrinolysis
Authors: von dem Borne Peter , Meijers Joost , Bouma Bonno 
Published: March 2018

IntroducationBlood coagulation is an important mechanism that maintains the integrity of the vascular system to prevent blood loss after injury. The conceptions on the working mechanism of coagulation are based on the waterfall or cascade model, which was already proposed more than 30 years ago, independently by Davie and Ratnoff (1) and MacFarlane (2). Blood coagulation was viewed as a series of linked proteolytic reactions in which zymogens are converted into serine proteases, ultimately leading to the formation of thrombin, which converts soluble fibrinogen into insoluble fibrin. Coagulation was thought to proceed via two pathways, an extrinsic and an intrinsic pathway. Activation of the extrinsic pathway of coagulation occurs by the exposition of tissue factor at the site of injury (3) whereas the intrinsic system is activated after exposure of plasma to an activating surface. Although the in vivo activating surface is unknown, the contact system was believed to play a role in the initiation of the intrinsic pathway. This system consists of factor XII, prekallikrein, high molecular weight kininogen and factor XI. The physiological relevance of the contact system is unclear, since a deficiency of factor XII, prekallikrein or high molecular weight kininogen does not result in a bleeding disorder. In contrast, patients deficient in factor XI, most common among Ashkenazi Jews, do suffer from variable bleeding abnormalities especially from tissues with high local fibrinolytic activity (urinary tract, nose, oral cavity, tonsils) (4, 5). This suggested there was an alternative route for the activation of factor XI, and recently such a route was described (6, 7). Thrombin was found to activate factor XI, even in the absence of a negatively charged surface (6-11), and factor XI was shown to play a role in the protection of the fibrin clot against lysis (9). In plasma the possibility cannot be excluded that the activation of factor XI by thrombin takes place via an intermediary component. Recently, it was shown that meizothrombin was capable of activating factor XI (12).
Comparative Studies on the Antiplatelet Effects of a Humanized Anti-Platelet Glycoprotein IIb/IIIa Antibody (YM337) and ReoPro under Flow Conditions
Authors: Kuwahara Mitsuhiro , Tsuji Shizuko , Miyata Shigeki , Nishio Kenji , Kaku Seiji , Suzuki Ken-ichi , Kawasaki Tomihisa , Yoshioka Akira , Sugimoto Mitsuhiko 
Published: March 2018

SummaryRecent clinical studies have shown that the interruption of platelet function appears to be effective for treatment of coronary occlusive diseases. For this purpose, a Fab fragment of humanized anti-platelet glycoprotein (GP) IIb/IIIa monoclonal antibody (YM 337) that exhibited an in vivo antithrombotic effect without prolongation of bleeding time in monkeys was previously characterized. In this study, the effect of YM 337 under physiological flow conditions with high or low shear rate was evaluated. The antiplatelet effects of YM 337 under varying wall shear rates were examined with the whole blood flow system. This technique allows real time visualization of the formation of fluorescence-labeled platelet thrombi on a collagen surface in a parallel plate flow chamber mounted on an epifluorescence microscope. The process of thrombus growth was also recorded in video tape and subjected to computer-assisted image analysis. We found that YM 337 displayed a high shear-preferential antiplatelet effect, while ReoPro, a control anti-GP IIb/IIIa antibody, did not show such shear dependency. The present findings therefore suggest that YM 337 might be a useful antiplatelet agent which can block pathological thrombotic events occurring under high shear, such as in coronary occlusive diseases.
Prevalence of 20210 A Allele of the Prothrombin Gene in Venous Thromboembolism Patients
Authors: Mercier Bernard , Oger Emmanuel , Chenu Eric , Abgrall Jean-François , Férec Claude , Mottier Dominique , Leroyer Christophe 
Published: March 2018

SummaryBackground. The 20210 A allele variation in the 3’ -untranslated region of the prothrombin gene was recently identified as a risk factor as regards deep venous thrombosis. Aim. To assess the frequency of the variation in unselected patients with a proven venous thromboembolism (VTE). Methods. The presence of the prothrombin variation was determined in all consecutive patients referred from July 1994 to August 1997 for a clinical suspicion of VTE, and in whom the diagnosis was confirmed. A control group consisted of bone marrow volunteer donors. Results. Of the 366 patients included, 17 (4.6%) were carriers of the 20210 A allele (95% CI, 2.4% to 6.7%). The mutation was present in 1.0% of the 400 controls. Odds ratio for having VTE in the presence of the 20210 A allele was 4.8 (95% CI, 1.5 to 19.8). Forty-six (12.5%) patients had the mutation of the factor V gene and five (1.4%) patients shared both mutations. After excluding the carriers of the factor V mutation, odds ratio for having VTE in the presence of the 20210 A allele was 3.7 (95% CI, 1.1 to 13.6). Mean age at admission as well as mean age of the first VTE episode were both significantly higher in patients free from the two mutations studied, as compared to carriers of the 20210 A allele (p = 0.04 and 0.01, respectively). Conclusion. Our findings in a large series of patients (1) confirm the 20210 A allele prothrombin gene as a risk factor for VTE. (2) suggest that its association with the factor V Leiden is not uncommon.
Factor XII Does not Initiate Prekallikrein Activation on Endothelial Cells
Authors: Røjkjær Rasmus , Hasan Ahmed , Motta Guacyara , Schousboe Inger , Schmaier Alvin 
Published: March 2018

SummaryIt is well known that on artificial surfaces, binding and autoactivation of factor XII (FXII) is the initiating event of plasma prekallikrein (PK) activation. We performed investigations to examine whether this mechanism was true for FXII activation on endothelial cells (HUVEC). Activation of PK on HUVEC required an optimal substrate and Zn2+ concentration, the latter of which varied with the buffer’s carrier protein. Maximal PK activation required the addition of 250 μM or 10 μM Zn2+ to buffers containing bovine serum albumin (BSA) or gelatin, respectively. However, the actual free Zn2+ concentration in these buffers was the same at 8 μM. In both BSA- and gelatin-containing buffers and using two different chromogenic substrates for FXII, no autoactivation of FXII on HUVEC was seen when incubated for up to 60 min. Rather, initiation of FXII enzymatic activity required the presence of PK. FXII activation after PK activation contributed to the extent of measured enzymatic activity, but its role was secondary because treatment with corn trypsin inhibitor or a neutralizing antibody to FXIIa did not abolish the measured enzymatic activity. They also reduced the activity to the level seen with PK activation alone. Alternatively, soybean trypsin inhibitor abolished the proteolytic activity associated with PK and FXII activation on HUVEC. Further, only normal human and FXII-deficient plasmas, not PK-deficient plasma, had the ability to generate proteolytic activity when incubated over endothelial cells. In a purified system, maximal PK activation was measured after a 10-15 min incubation depending upon the concentration of reactants. When FXII was added with the PK, maximal activation occurred within 7.5-10 min. In normal human or FXII-deficient plasmas, but not in PK-deficient plasma, maximal activation was seen in 4 min. These data indicate that on HUVEC, unlike artificial surfaces, PK activation when bound to HK is the initiating activation event in this system. FXII activation is secondary to PK activation and contributes to the extent of measured enzymatic activity. These data challenge the accepted dogmas of “contact activation” and suggest that on biologic membranes a new notion as to how this system is activated needs to be considered.
Cleavage Requirements of Factor V in Tissue-factor Induced Thrombin Generation
Authors: Thorelli Elisabeth , Kaufman Randal , Dahlbäck Björn 
Published: March 2018

SummaryFactor V (FV) activation is the result of cleavages at Arg709, Arg1018 and Arg1545 by thrombin or FXa. The relative importance of these cleavages in tissue factor (TF) induced thrombin generation in plasma and in a purified system was elucidated with recombinant FV in which the three sites had been eliminated one by one or in combinations. The mutants were analyzed with a clotting assay using FV-deficient plasma and in a TF induced thrombin generation system using plasma or purified components. Surprisingly, in the standard FV clotting assay, all mutants gave similar clotting activities and the thrombin generation curves obtained with wild-type and thrombin-resistant FV were similar. Differences in clotting activities and thrombin generation patterns between wild-type and thrombin-resistant FV were only observed when lower TF concentrations were used. The thrombin generation curve obtained in plasma containing wt FV was characterized by a short lag phase and a subsequent phase of rapid thrombin generation (propagation phase). The Arg709 to Gln mutation yielded a slightly prolonged lag phase and the rate of thrombin generation during the propagation phase was approximately 5-fold lower than that observed with wt FV. The Arg1018 to Ile mutation only slightly affected the thrombin generation curve, whereas the Arg1545 to Gln mutation yielded a prolonged lag phase and decreased maximum thrombin activity. Thrombin-resistant FV (mutated at all three sites) yielded a prolonged lag phase and poor thrombin generation during the propagation phase. The purified system further demonstrated the importance of the three cleavage sites for rapid and sustained thrombin generation. The results demonstrate that cleavages at positions 709, 1018 and 1545 are not required for assembly of a FXa-FV complex expressing low but significant prothrombinase activity but that all three sites in different ways are important for the creation of a FVa which maximally supports the FXa-mediated activation of prothrombin.
Correlates of Antithrombin, Protein C, Protein S, and TFPI in a Healthy Elderly Cohort
Authors: Sakkinen Pamela , Cushman Mary , Psaty Bruce , Kuller Lewis , Bajaj S. Paul , Sabharwal Arun , Boineau Robin , Macy Elizabeth , Tracy Russell 
Published: March 2018

SummaryThe majority of fatal acute myocardial infarctions occur in the elderly. Since these events are predominantly thrombotic, we studied the cross-sectional associations of the anticoagulant proteins Anti-thrombin, Protein C, Protein S, and Tissue Factor Pathway Inhibitor (TFPI) in a subgroup (n = 400) of the Cardiovascular Health Study (a study of healthy men and women ≥65 years) free of clinical cardiovascular disease (CVD).We did not observe any strong age-associated trends, although Protein C was lower in older women (p ≤0.001), and TFPI was higher in older men (p ≤0.01). The inhibitors were highly intercorrelated, and were associated with increased levels of inflammation-sensitive proteins (e.g., fibrinogen, plasminogen), lipids (especially total and LDL-cholesterol), and coagulation factors, such as Factors VIIc, IXc, and Xc. None was associated with the procoagulant markers Prothrombin Fragment F1-2 or Fibrinopeptide A. Only TFPI was associated with subclinical atherosclerosis: ankle-arm index and internal carotid artery stenosis, p trend ≤0.01; and carotid wall thickness, p trend ≤0.05. In multivariate analysis the independent predictors of TFPI were levels of fibrinogen; the fibrinolytic marker plasminantiplasmin complex; LDL-cholesterol; and carotid wall thickness (R2 for the model = 0.35).In summary, the inhibitors did not appear to increase with age, and were predominantly associated with inflammation markers and lipids. Since markers of thrombin production do increase with age, we hypothesize that an age-related hemostatic imbalance may ensue, with associated increased thrombotic risk. Only TFPI was associated with subclinical CVD, suggesting that it may more closely reflect endothelial damage. (250)
Native Atherosclerosis and Vein Graft Arterialization: Association with Increased Urokinase Receptor Expression In Vitro and In Vivo
Authors: Golden Michael , Raghunath P. N. , Tomaszewski John , David Mary , Kuo Alice , Kariko Katalin , Barnathan Elliot , Okada S. Steve 
Published: March 2018

SummaryInteraction of proteases with cell surface receptors may modulate cell adhesion, migration, invasion, and matrix degradation. Since the plasminogen activator system has been hypothesized to play a role in intimal thickening after various types of vascular injury, we first studied the expression of urokinase receptor (u-PAR) protein and mRNA by smooth muscle cells (SMC) grown in explant cultures from normal and diseased vessels. Using equilibrium binding studies with radiolabeled 125I-labeled single chain urokinase-type plasminogen activator (scu-PA), we determined that SMC cultured from atherosclerotic arteries expressed a higher maximal number of binding sites/cell (3.6 ± 0.4 × 105 sites/cell vs. 2.1 ± 0.3 × 105, ± SEM, p <0.05) with a similar affinity (Kd = 1.5 ± 0.1 vs. 1.2 ± 0.2 nM, p = ns). However, SMC subcultured from diseased saphenous vein grafts expressed the highest levels of u-PAR compared to SMC from normal saphenous vein (4.8 ± 0.6 × 105 sites/cell vs. 1.6 ± 0.9 × 105, ± SEM, p <0.05). Using binding studies and Northern analysis, we demonstrated a dose and time dependent upregulation of u-PAR protein and mRNA expression respectively in human SMC in response to serum stimulation. Using a rabbit specific u-PAR cDNA probe, we demonstrated a similar upregulation of u-PAR mRNA both in rabbit aortic SMC in culture in response to serum stimulation and up to a 20 fold increase in u-PAR mRNA in rabbit jugular veins in response to implantation as arterial grafts in vivo. Finally, to confirm that u-PAR mRNA is upregulated in human vessels after injury, we performed immunohistochemistry and in situ hybridization studies on coronary arteries, normal saphenous veins and saphenous veins from 10 weeks to 13 years after implantation as grafts. u-PAR mRNA was found mainly in the periadventitial microcirculation in normal veins, but was found to be upregulated in the neointima and media of thickened veins in both macrophages and smooth muscle cells. SMC near the internal elastic laminae in diseased coronary arteries appeared to express increased u-PAR mRNA. These data suggest that this increased expression of u-PAR may contribute to early lesion development.
Fibrino(geno)lytic Properties of Purified Hementerin, a Metalloproteinase from the Leech Haementeria depressa
Authors: Chudzinski-Tavassi Ana Marisa , Kelen Eva Maria , Rosa Ana Paula de Paula , Loyau Stephane , Sampaio Claudio , Bon Cassian , Anglés-Cano Eduardo 
Published: March 2018

SummaryThe fibrino(geno)lytic protein designated hementerin contained in crude extracts of the salivary complex of Haementeria depressa leeches was purified to apparent homogeneity by gel filtration, ion exchange chromatography and preparative SDS-PAGE. It is a single-chain 80 kDa, PhMeSO2F-resistant, calcium-dependent, metalloproteinase, which specifically degrades fibrin(ogen) through a plasminogen-independent pathway. The amino terminal sequence of 8 residues shows 80% similarity with hementin, another fibrino(geno)lytic protein purified from Haementeria ghilianii leeches. However, their activities differ somewhat in terms of kinetics and with regard to the structure of the fibrin(ogen) fragments they may produce. Cleavage by hementerin of fibrinogen Aα, γ and Bβ chains, in that order, produces 270 kDa to 67 kDa fragments which differ from those produced by plasmin. Hementerin was also able to degrade cross-linked fibrin although at a lower rate as compared to fibrinogen. In conclusion, hementerin is a plasminogen-independent fibrino(geno)lytic metalloproteinase that degrades fibrinogen faster than fibrin, prevents blood coagulation and destroys fibrin clots in vitro.
Deletion Polymorphism in the Angiotensin-converting Enzyme Gene as a Thrombophilic Risk Factor after Hip Arthroplasty
Authors: Dilley Anne , Saidi Parvin , Evatt Bruce , Austin Harland , Zawadsky Joseph , Harwood David , Ellingsen Dorothy , Barnhart Elizabeth , Phillips Donald , Hooper William Craig , Philipp Claire 
Published: March 2018

SummaryDespite thromboprophylaxis, deep vein thrombosis is a common complication of major orthopedic surgery. Predisposing genetic risk factors are unknown. In this case-control study, we investigated the association of the insertion (I)/deletion (D) angiotensin converting enzyme (ACE) gene polymorphism, Factor V Leiden (R506Q) mutation, and 5,10 methylenetetrahydrofolate reductase (MTHFR) gene polymorphism with post-operative venous thrombosis in 85 patients who underwent elective total hip arthroplasty. The odds of a thrombotic event following hip surgery among subjects with the DD genotype of the ACE gene was increased more than 10-fold compared to subjects with the II genotype (odds ratio 11.7 [95% confidence interval 2.3-84.5]); it was increased 5-fold in subjects with the ID genotype compared to the II genotype (odds ratio 5.0 [95% confidence interval 1.1-34.9]). Mean plasma ACE level in control subjects not on ACE inhibitors at the time of study (n = 43) was lowest in persons homozygous for the I allele (18.9 ± 7.95 U/l), intermediate in patients with the ID genotype (31.6 ± 10.8 U/l) and highest in subjects homozygous for the D allele (44.0 ± 7.14 U/l). Mean plasma ACE level among cases was higher (33.0 U/l, n = 25) than among controls (29.4 U/l, n = 43) but this difference was not statistically significant. Neither the Factor V Leiden mutation nor MTHFR gene polymorphism increased the risk of thrombosis following hip replacement. These results demonstrate that the I/D ACE gene polymorphism is a potent risk factor for thrombosis in subjects undergoing total hip arthroplasty.