bluuebunny/crossref_metadata_2025_split huggingface dataset:
Two Naturally Occurring Mutations on FVII Gene (S363I-W364C) Altering Intrinsic Catalytic Activity
Authors: De Cristofaro Raimondo , Akhavan Sepideh , Carew Josephine , Landolfi Raffaele , Bauer Kenneth , Mannucci Pier Mannuccio , Peyvandi Flora 
Published: March 2018

SummaryFactor VII (FVII) requires the cleavage of an internal peptide bond and the association with tissue factor (TF) to attain its fully active FVIIa conformation. This event alone leaves FVIIa in a zymogen-like state of relatively low specific activity. The TF-induced allosteric enhancement of FVIIa’s activity contributes to the procoagulant activity of the complex. We have characterized two naturally occurring mutations (S363I W364C) on FVII gene. Both homozygous patients for each mutation have a normal FVII:Ag level associated to an undetectable FVII coagulant activity. The patient carrying the allele 364C had a more severe hemorrhagic diathesis than the S363I mutant. To understand the mechanism of these deficiency, in vitro expression analysis with further biochemical characterization of recombinant proteins of both mutants FVII-363I, FVII-364C and wild type (WTFVII) FVII constructs were done. The results recapitulated the patients’ plasma data with normal Ag level and no detectable coagulant activity. The D-F-Pip-R-pNA and CH3SO2-D-CHA-A-But-R chromogenic substrates were used to evaluate the amidolytic activity of WT and mutant FVII in presence and absence of recombinant tissue factor (rTF). Binding of FVII to rTF by a solid phase binding assay was done using recombinant human rTF. The results of amidolytic assays showed that rTF enhances 28 fold the value of the specificity of constant (kcat/Km) in WT but no activity was detectable in either mutant constructs under any condition. The equilibrium dissociation constant of rTF-FVIIa interaction showed Kd equal to 4.4 ± 0.2nM, 4.9 ± 0.5nM and 6 ± 0.9 of WT, 363I and 364C FVII forms, respectively. The Kd values of the non activated forms were equal to 24.7 ± 3.3, 24.4 ± 3.1 and 20.6 ± 4nM, respectively. These data demonstrate that, compared to the WT form, FVII-363I and FVII-364C have no significant affinity change for TF and that the detrimental effect of these two mutations is attributable to the loss of an efficient catalytic machinery in the FVII molecule causing a severe deficiency of coagulant activities.
The In Vitro Analysis of the Coagulation Mechanism of Activated Factor VII Using Thrombelastogram
Authors: Kawaguchi Chiharu , Hanesaka Yae , Yoshioka Akira , Takahashi Yukihiro 
Published: March 2018

SummaryWe investigated the effects of addition of recombinant activated coagulation factor VII (rFVIIa) to coagulation factor-deficient plasma and whole blood, using thrombelastograms (TEGs). The addition of rFVIIa to factor II-or X-deficient plasma did not correct hemostatic parameters, whereas it produced partial responses in factor V-, VIII-or IX-deficient plasma and good responses in factor VII-, XI-or XII-deficient plasma. Furthermore, the addition of rFVIIa and platelets (30-100 X 103/µl) to platelet-poor plasma produced marked corrections, producing TEGs similar to those of platelet-rich plasma. These results indicate that factors II and X are essential for the hemostatic effects of rFVIIa, and that factors V and VIII promote these effects. We believe that TEGs are, at present, one of the most useful tools for evaluating in vitro hemostatic effects of rFVIIa.
Influence of Plasminogen Deficiency on the Contribution of Polymorphonuclear Leucocytes to Fibrin/ogenolysis
Authors: Zeng Biao , Bruce David , Kril Jillian , Ploplis Victoria , Freedman Ben , Brieger David 
Published: March 2018

SummaryPlasminogen knock-out (PG−/−) mice provide an unique opportunity for the study of alternative mediators of fibrinolysis. Polymorphonuclear leucocytes (PMNs) contain non-plasmin fibrinolytic proteases, however the degree to which these cells contribute to fibrin(ogen) degradation in these animals is not known. Thrombi were generated in carotid arteries and jugular veins of PG−/− and wild type (PG+/+) mice following adventitial application of a 20% ferric chloride solution. PMNs, identified histologically on H&E staining and by immunohistochemistry using anti-mouse PMN RB6-8C5 antibody, accumulated within the thrombus by 6 h after the injury and peaked at 24 h. There was significantly greater retention of PMNs within the thrombi of PG−/− mice from 48 to 72 h than in the PG+/+ controls (at 72 h: PG−/− 255 ± 41 cell/mm2 (n = 5), PG+/+ 61 ± 10 cell/mm2 (n = 5), p <0.01 in the arterial thrombi; PG−/− 252 ± 50 cell/mm2 (n = 5), PG+/+ 100 ± 36 cell/mm2 (n = 5), p <0.05 in the venous thrombi), providing potential for more PMN derived fibrinolytic enzymes to be present at late times after a thrombotic challenge in PG−/− mice relative to the PG+/+ controls.Intact PMNs were elicited from the peritoneal cavities of PG−/− and PG+/+ mice following 4% thioglycolate stimulation. In vitro studies showed PMNs from PG−/− mice to release greater quantities of 10% trichloroacetic acid (TCA)-soluble fibrinopeptides from I125-labeled fibrinogen, than cells from PG+/+ controls although these differences did not become apparent until after 24 h of incubation (at 72 h incubation: PG−/− 918 n /10 X 106 cells/0.5 ml, PG+/+ 589 ng/10 X 106 cells/ ml p = 0.005). Furthermore, autoradiographic analysis of the I125labeled fibrinogen degradation products showed the cleavage pattern by PG−/− PMNs to be distinct from that produced by PG+/+ PMNs.These data suggest that a relatively greater role for PMNs-initiated fibrinolysis exists in the setting of plasminogen deficiency, although this prominence only becomes evident more than 24 h after the thrombotic insult. In addition, mechanisms responsible for the process in PG−/− mice may be distinct from those primarily responsible for the process in PMNs from PG+/+ mice.
Physical and Enzymatic Perturbation of the Architecture of the Tunica media Destroys its Inherent Thromboresistance
Authors: Komorowicz Erzsebet , McBane Robert , Fass David 
Published: March 2018

SummaryThe media layer of the arterial cryo-cross sections, is defective for vWf-dependent platelet adhesion. Exposure of the same layer by stripping off the most inner portions of the vessel wall results in a highly thrombogenic surface. Stripping or balloon dilation was applied to porcine arteries prior to functional assays. Cryosections of treated or untreated arteries were perfused with porcine blood at 3350 s-1 and platelet deposition was detected by indirect immunofluorescence. Following balloon dilation, vWf-dependent platelet deposition increased; covering 9.08 ± 1.36% of the total media surface area, this value for untreated vessels was 0.88 ± 0.14%. A 10-fold increase was also found in the binding of vWf-coated fluorescent beads to the media. In addition to mechanical procedures, treatment by serine-proteases like trypsin, chymotrypsin and proteinase 3, or by chondroitinase ABC, but not by heparitinase also resulted in a 7-10-fold increase in platelet coverage over the media. Collagen in the media may be complexed with another vessel wall component shielding the vWf-binding sites. Mechanical or biochemical processes unmask these sites, and increase the thrombogenicity of the vessel wall.
Thrombosis in Children: Current Perspective and Distinct Challenges
Authors: Richardson Matthew , Allen Geoffrey , Monahan Paul 
Published: March 2018

SummaryCoincident with a true increase in the incidence of thrombosis in childhood has come an appreciation of the impact of thromboembolic events upon children. In part, the greater awareness of childhood thrombosis reflects improved diagnostic imaging, which allows more sensitive identification of clots in infants and children. At the same time, advances in supportive care have meant that more children are being exposed to, surviving and living with thromboembolic risk factors and complications than previously. Because data regarding pediatric thrombosis have been lacking, treatment strategies have been extrapolated from experience in adults. This approach, however, results in diagnostic and therapeutic pitfalls. An understanding of issues unique to pediatric thrombosis is required; recent insights and the ongoing challenges are reviewed.Following the submission of this manuscript, the Subcommittee for Perinatal and Pediatric Thrombosis and of the Scientific and Standardization Committee of the International Society on Thrombosis and Haemostasis (ISTH) generated two relevant communications, published in the July, 2002 issue of Thrombosis and Haemostasis. While the positions communicated, entitled “Laboratory testing for thrombophilia in pediatric patients (117)” and “Recommendations for tPA thrombolysis in children (118)” do not conflict with this manuscript, they will be of interest to the reader.
Thrombin-induced Hyperactivity of Platelets of Young Stroke Patients
Authors: Vanschoonbeek Kristof , Feijge Marion , Keuren Jeffrey , Hemker H. , Lodder Jan , Hamulyák Karly , van Pampus Elisabeth , Heemskerk Johan 
Published: March 2018

SummaryActivated platelets are implicated in the development of premature arterial vascular diseases, in particular ischemic stroke. Since elevated cytosolic [Ca2+]i is an integrative marker of platelet activation, we determined the generation of Ca2+ signal in stimulated platelets from 26 young patients recuperating from stroke, 20 patients with symptomatic peripheral arterial disease, and 56 healthy volunteers. Even in the presence of aspirin, the platelets from various individuals showed highly different thrombin-induced Ca2+ responses. On average, the thrombin-induced Ca2+ response was increased for platelets from either patient group in comparison to the controls (P <0.04). Relatively more stroke patients had high-responsive platelets (27%, 7/26) than patients with peripheral arterial disease (10%, 2/20) or healthy subjects (4%, 2/56). The average prothrombinase activities of platelets from patients and controls were similar, but 3 out of 6 patients with increased thrombin-induced Ca2+ responses also exhibited high prothrombinase activity. In a follow-up study, the subject-dependent thrombin-induced Ca2+ response was found to correlate strongly with the platelet response to protease-activated receptor 1 (PAR1) agonist (r = 0.91), but was not linked to the PlA1/2 polymorphism. It is concluded that a significant part of young patients with stroke have platelets with hyperactivity toward thrombin, which is not normalised by aspirin treatment. Furthermore, the subject-dependent variation in thrombin-induced signalling is likely to involve PAR1-mediated platelet activation.
Clustering of Thrombotic Factors with Insulin Resistance in South Asian Patients with Ischaemic Stroke
Authors: Catto Andrew , Grant Peter , Kain Kirti 
Published: March 2018

SummaryWe aimed to investigate significant correlations of insulin resistance with thrombotic factors in South Asians with stroke. Correlations of Homeostasis Model Assessment (HOMA)(as a surrogate of insulin resistance) were analysed with 6 thrombotic factors in 140 South Asian patients with a history of confirmed (by computerised tomography) ischaemic stroke. Age and sex adjusted HOMA was correlated to waist-hip ratio (r = 0.38, p = 0.0001), triglycerides (r = 0.22, p = 0.03), systolic blood pressure (r = 0.21, p = 0.04), tissue plasminogen activator (t-PA) (r = 0.22, p = 0.04); plasminogen activator inhibitor 1(PAI-1) (r = 0.26, p = 0.02); fibrinogen (r = 0.25, p = 0.02); and factor VII antigen (r = 0.21, p = 0.06). On regression analysis, with HOMA as dependent variable and significant correlates as independent variables in the model, HOMA was independently associated with PAI-1 antigen. There is extensive clustering of metabolic and thrombotic factors with insulin resistance in South Asian patients with ischaemic stroke, which may contribute to high prevalence of vascular disease in this population.
European Concerted Action on Anticoagulation (ECAA): International Normalized Ratio Variability of CoaguChek and TAS Point-of-Care Testing Whole Blood Prothrombin Time Monitors
Authors: Keown M. , Chauhan N. , Shiach C. , van den Besselaar A. M. H. P. , Tripodi A. , Jespersen J. , Poller L. 
Published: March 2018

SummaryThe object was to assess the variability in displayed International Normalised Ratio (INR) between monitors of the same manufacture using whole blood samples from the same subjects. Two brands of monitor, CoaguChek Mini and the TAS PT-NC were tested.14 instruments of each brand were tested on the same day at the same laboratory by the same operator using identical blood samples to avoid between-centre differences in samples and operator technique. Whole blood samples from two normal donors and four coumarintreated patients were tested to assess between-instrument variability of INR.Results have been coded. There was a much wider dispersion of INR on Brand B than on Brand A. One Brand A instrument failed to give a result with one of the two whole blood samples from one patient. One Brand B monitor gave an aberrant result with one of the samples from a normal subject.On both brands of monitor, INR variability appeared to be due mainly to duplication differences rather than between-instrument variability on both normal and coumarin whole blood samples.
A Novel Hemizygous Bernard-Soulier Syndrome (BSS) Mutation in the Amino Terminal Domain of Glycoprotein (GP)Ibβ- Platelet Characterization and Transfection Studies
Authors: Nurden Alan , Nurden Paquita , Combrié Robert , Claeyssens Ségolène , Moran Niamh , Kenny Dermot , Hillmann Andrew 
Published: March 2018

SummaryGlycoprotein (GP) Ib-V-IX is a unique adhesion receptor complex on platelets. Mutations in GPIbα, Ibβ, and IX can lead to the rare bleeding disorder, Bernard-Soulier Syndrome (BSS). Here, we report a novel hemizygous variant of BSS in which Pro29 in one GPIbβ allele is substituted by a Leu (GPIbβ:P29L). Fluoresence in situ hybridisation revealed that the 22q11 locus was deleted from the homologous chromosome. The pedigree was determined and revealed inheritance of the GPIbβ:P29L allele from the father. Flow cytometry with a range of antibodies detected no expression of GPIb-V-IX on the surface of the patient’s platelets. Western blotting revealed an absence of GPIbα and GPIbβ from platelet lysates. Co-expression of GPIbβ:P29L with normal GPIbα and GPIX in a heterologous cell system confirmed that the mutant subunit did not support surface expression of the complex. Interestingly, residual expression of GPIbβ:P29L anchored in the plasma membrane alone was now seen. This novel BSS mutation expressed in heterologous cells is in agreement with recent in vitro evidence that the correct conformation of the amino terminal region of GPIbβ is required for normal expression of the intact receptor complex.
Transfer of Tissue Factor from Platelets to Monocytes: Role of Platelet-Derived Microvesicles and CD62P
Authors: Scholz Thomas , Temmler Uta , Krause Siegfried , Heptinstall Stan , Lösche Wolfgang 
Published: March 2018

SummaryTissue factor (TF) is the most important initiator of intravascular coagulation. Platelets contribute to TF exposure on monocytes, but the mechanism is not completely understood. Here we examined the possibility that platelets may release TF that can be transferred to monocytes by platelet-derived microvesicles. When human citrated platelet-rich plasma was incubated with collagen there was an increase in the plasma levels of TF and CD62P. Incubation of plasma obtained from collagen-stimulated PRP with a sediment of red and white blood cells resulted in an increase in the number of monocytes that express TF, CD62P and the platelet-specific antigen CD42a on their surface. This transfer of platelet-derived antigens to monocytes was reduced when CD62P was blocked by a specific antibody or when platelet-derived microvesicles were removed from the plasma either by high speed centrifugation (17,500 X g for 30 min) or by filtration (pore size 0.2 µm). The data indicate that platelet-derived microvesicles that are released from collagen-stimulated platelets may carry TF, CD62P and CD42a and may transfer these antigens to the surface of monocytes. The interaction of platelet-derived microvesicles with monocytes and the transfer of TF to monocytes strongly depend on CD62P.
Soluble Tissue Factor Interferes with Angiostatin-mediated Inhibition of Endothelial Cell Proliferation by Lysine-specific Interaction with Plasminogen Kringle Domains
Authors: Magdolen Viktor , Herzog Ute , Miles Lindsey , Kirschenhofer Angela , Baretton Gustavo , Luther Thomas , Albrecht Sybille 
Published: March 2018

SummaryExperimental and clinical data suggest that tissue factor (TF), the major initiator of blood coagulation cascade, as well as proteases and components of the fibrinolytic system are involved in tumor growth at least in some solid tumors via effects on angiogenesis. Whereas the proand anti-angiogenic effects of the plasminogen/plasmin system and plasminogen kringle domains, respectively, are well characterized, the pathways responsible for the pro-angiogenic properties of TF remain poorly understood. To learn more about the biological significance of the recently described binding of plasminogen to the extracellular domain of TF, we examined the effects of soluble TF (sTF) on angiostatin-inhibited proliferation of endothelial cells.In solid phase binding assays, we found that sTF binds specifically to plasminogen, to the plasminogen kringle domains K1-3, K1-5, K4, as well as to mini-plasminogen. Inhibition of binding of plasminogen and its kringle domains to sTF by the lysine analog 6-aminohexanoic acid (AHA) suggests that lysine-binding sites are involved in plasminogen interaction with TF. Moreover, in the presence of sTF, the inhibitory effect of K1-5 on bFGF-mediated HUVEC proliferation was dose-dependently and saturably abolished. This suggests that TF can interfere with the antagonistic effect of K1-5 on endothelial cell proliferation. In contrast, sTF by itself had no effect on the endothelial cell proliferation. Whereas the interference of TF with K1-5-mediated effect was prevented by AHA, this lysine analog did not abolish the proliferation inhibition of K1-5. In conclusion, the binding of sTF to the plasminogen fragment K1-5 seems to antagonize the anti-angiogenic effects of this plasminogen fragment.
Predisposing factors for enlargement of intracerebral hemorrhage in patients treated with warfarin
Authors: Minematsu Kazuo , Naritomi Hiroaki , Sakata Toshiyuki , Yamaguchi Takenori , Yasaka Masahiro 
Published: March 2018

SummaryTo elucidate predisposing factors for enlargement of intra-cerebral hematoma (ICH) during warfarin therapy, we reviewed 47 patients on warfarin who developed acute ICH and determined relationships among ICH enlargement, INR reversal and clinical data. Among 36 patients treated to counteract the effects of warfarin within 24 h of onset, ICH increased in 10 patients (enlarged group), but remained unchanged in the remaining 26 (unchanged group), while ICH remained unchanged in another 11 patients in whom the effect of warfarin was reversed after 24 h. The international normalized ratio (INR) was counteracted immediately in 11 patients treated with prothrombin complex concentrate (PCC) but gradually in the other 36 treated by reducing the dose of warfarin, or by administering vitamin K or fresh frozen plasma. Multivariate analysis with a logistic regression model showed an INR value <2.0 at admission or for 24 h after immediate INR correction with PCC prevented ICH enlargement (OR 0.069, 95%CI 0.006-0.789, p = 0.031). An INR value of >2.0 within 24 h of ICH seems an important predisposing factor for ICH enlargement.
Body mass index is associated with the development of the post-thrombotic syndrome
Authors: Piantanida Eliana , Dentali Francesco , Steidl Luigi , Mera Valentina , Squizzato Alessandro , Marchesi Chiara , Venco Achille , Ageno Walter 
Published: March 2018

SummaryPost-thrombotic syndrome (PTS) is a chronic complication of deep vein thrombosis (DVT). Little is known about prognostic factors that might identify patients at high risk for the development of PTS. Body mass index (BMI) has been previously reported to be associated to the development of PTS. The aim of this study was to assess the association between BMI and other anthropometric parameters and PTS in a general population of DVT patients.In a prospective cohort study, 83 consecutive patients with objective diagnosis of DVT underwent physical examination. BMI was recorded at baseline and at 12 months, and waist circumference was recorded at 12 months to assess individual patterns of body fat distribution. The presence of PTS at 12 months was ascertained using a validated clinical scale. Sixty-three patients (75.9%) were overweight or obese at 12 months, 60 (72.3%) had a weight gain over 1 year. Twenty patients developed PTS (24.1%). Mean BMI was significantly higher in patients who developed PTS than in patients who did not (29.6 and 27.2 Kg/m2, respectively, p = 0.022). A BMI of > 28 Kg/m2 predicted early onset of PTS (OR 3.54, 95% CI 1.07-12.08, p = 0.017). Neither patterns of fat distribution nor weight gain in 1 year were correlated with PTS (p = 0.918 and p = 0.775, respectively).BMI is significantly correlated with the development of PTS. Patients with DVT should be encouraged to avoid weight gain. Reducing patient weight might be an important strategy to prevent PTS.
Measurement of soluble fibrin monomer-fibrinogen complex in plasmas derived from patients with various underlying clinical situations
Authors: Kazahaya Yumiko , Shintani Yuichi , Yamazumi Kensuke , Eguchi Yutaka , Koga Shin , Wada Hideo , Matsuda Michio , Nakahara Kunihiko 
Published: March 2018

SummaryWe previously reported a monoclonal antibody named IF-43 that specifically recognizes thrombin-modified fibrinogen (desAA- and desAABB- fibrin monomer) bound with fibrinogen or other D1 domain-containing plasmic fragments such as fragments X, Y, and D1, but not intact fibrinogen or cross-linked fibrin degradation products (XDP). Here, we tentatively named such complexes, soluble fibrin monomer (FM) -fibrinogen complex.By utilizing IF-43, we have developed a kit to measure soluble FM-fibrinogen complex and compared the profiles with those of two established molecular markers for thrombo-embolic disorders: i.e. the thrombin-antithrombin complex (TAT) and the D-dimer in plasma of patients who underwent surgery without any thrombo-embolic complications. The result indicated that soluble FM-fibrinogen complex is a distinct entity from the two established molecular markers. We have also attempted to observe their profiles in patients with the disseminated intravascular coagulation syndrome (DIC). Although the profiles of soluble FM-fibrinogen complex in individual patients appeared to vary from one patient to the other, the plasma level of soluble FM-fibrinogen complex was found to be increased at the initial phase of disseminated intravascular coagulation syndrome. Thus, the soluble FM-fibrinogen complex may serve as an independent molecular marker for the detection of thrombin generation and the diagnosis of thrombosis. The soluble FM-fibrinogen complex may also serve as a risk factor for thrombosis, because it may precipitate as insoluble complexes beyond its threshold in plasma, or when it is modified by thrombin.Part of this paper was originally presented at the 17th International Fibrinogen Workshop of the International Fibrinogen Research Society (IFRS) held in Munich, Germany, September, 2002.