bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification of Three Novel Mutations in Hereditary Protein S Deficiency
Authors: Bustorff Teresa C , Freire Isabel , Gago Teresa , Crespo Francisco , David Dezsö 
Published: July 2018

SummaryWe report the application of single-stranded conformation polymorphism (SSCP) analysis to the screening of 15 functionally important Protein S (PS) gene (PSα) regions (4.243 Kb) in 6 unrelated families with PS deficiencies. Direct sequencing of the fragments with altered migration patterns led to the identification of the corresponding molecular alterations. A missense mutation, G to T transversion at codon Cys598, and two different alterations, leading either to allelic exclusion, or premature termination of the protein translation: a G to A transition at codon Trp465 and a 1 nt (T) insertion at codon 265, were identified. The 1 nt insertion was observed in three apparently unrelated families but with a common geographical origin and the mutated allele was undetectable in platelet mRNAs of affected individuals. Family analysis confirmed, in each case, a perfect cosegregation of the mutation with the PS deficiency. We conclude that these alterations represent the causative mutations.
Haemostatic Variables in Pacific Islanders Apparently Free from Stroke and Ischaemic Heart Disease – The Kitava Study
Authors: Lindeberg Staffan , Berntorp Erik , Carlsson Roland , Eliasson Mats , Marckmann Peter 
Published: July 2018

SummaryWe cross-sectionally measured plasminogen activator inhibitor-1 (PAI-1) activity, fibrinogen, factor VII (FVII:C) and VIII (FVIII:C) coagulant activity, and von Willebrand factor antigen (VWF:Ag) in 162 traditional horticulturalists older than 40 years from the tropical island of Kitava, Papua New Guinea, where the intake of western food is negligible and where stroke and ischaemic heart disease appear to be absent. Identical analyses were made in Swedish subjects of comparable ages.Kitavans had markedly lower PAI-1 activity, with 85% of males and 100% of females having PAI-1 activity ≤5 U/ml, as compared with 22 and 14% in Swedish males and females (p <0.0001). Surprisingly, Kitavans also had higher FVII:C, FVIII: C and VWF: Ag. Fibrinogen was 10% lower in Kitavan males while 25% higher in Kitavan females.The very low PAI-1 activity in Kitavans may explain some of their apparent freedom from cardiovascular disease and probably relates to their extreme leanness.
Coagulation and Fibrinolysis Factors in Healthy Subjects Consuming High Stearic or Trans Fatty Acid Diets
Authors: Mutanen Marja , Aro Antti 
Published: July 2018

SummaryThe effects of stearic acid (Cl8:0) and trans fatty acids on variables related to coagulation and fibrinolysis were studied in 80 healthy humans average age 29 ± 9 years. All subjects consumed a baseline diet high in saturated fatty acids, mainly from dairy fat for 5 weeks. After this baseline diet they were allocated either to a diet high (8.7% of energy, En%) in trans fatty acids from partially hydrogenated vegetable oil (40 subjects) or a diet high (9.3 En%) in stearic acid (40 subjects) for 5 weeks. All diets contained 32.2-33.9 En% fat, 14.6-15.8 En% saturated plus trans fatty acids, 12.2-12.5 En% cis-monounsaturated and 2.9-3.5 En% polyunsaturated fatty acids and 216-250 mg/10 MJ cholesterol. The fats were mixed into solid foods and almost all daily food was provided.In comparison with the baseline dairy fat diet no change was observed in the concentrations of plasma fibrin degradation products and D-dimers. Also the factor VII coagulant activity (F VII :C), tissue type plasminogen activity (tPA) and plasminogen activator inhibitor activity (PAI-1) were not affected by the experimental diets. Small increase in plasma fibrinogen concentration during the stearic acid diet was statistically significant (from 3.49 to 3.63 g/1; p = 0.041), but probably without any biological significance. Both diets increased plasma level of lipoprotein Lp(a). It can be concluded that as far as coagulation and fibrinolysis are concerned there is no need to differentiate between stearic acid or trans monoenoic fatty acids.
Screening for the FV: Q506 Mutation – Evaluation of Thirteen Plasma-based Methods for their Diagnostic Efficacy in Comparison with DNA Analysis
Authors: Tripodi Armando , Negri Barbara , Bertina Rogier M , Mannucci Pier Mannuccio 
Published: July 2018

SummaryThe factor V (FV) mutation Q506 that causes resistance to activated protein C (APC) is the genetic defect associated most frequently with venous thrombosis. The laboratory diagnosis can be made by DNA analysis or by clotting tests that measure the degree of prolongation of plasma clotting time upon addition of APC. Home-made and commercial methods are available but no comparative evaluation of their diagnostic efficacy has so far been reported. Eighty frozen coded plasma samples from carriers and non-carriers of the FV: Q506 mutation, diagnosed by DNA analysis, were sent to 8 experienced laboratories that were asked to analyze these samples in blind with their own APC resistance tests. The APTT methods were highly variable in their capacity to discriminate between carriers and non-carriers but this capacity increased dramatically when samples were diluted with FV-deficient plasma before analysis, bringing the sensitivity and specificity of these tests to 100%. The best discrimination was obtained with methods in which fibrin formation is triggered by the addition of activated factor X or Russell viper venom. In conclusion, this study provides evidence that some coagulation tests are able to distinguish carriers of the FV: Q506 mutation from non-carriers as well as the DNA test. They are inexpensive and easy to perform. Their use in large-scale clinical trials should be of help to determine the medical and economic benefits of screening healthy individuals for the mutation before they are exposed to such risk factors for venous thrombosis as surgery, pregnancy and oral contraceptives.
Selective Stimulation of Tissue-Type Plasminogen Activator (t-PA) In Vivo by Infusion of Bradykinin
Authors: Brown Nancy J , Nadeau John H , Vaughan Douglas E 
Published: July 2018

SummaryAngiotensin converting inhibitors (ACEI) not only decrease angiotensin II (Ang II) but also potentiate the effects of bradykinin. Bradykinin is a potent stimulus to tissue type plasminogen activator (t-PA) secretion in animal models. In this study, we tested the hypothesis that bradykinin increases t-PA levels in humans.Bradykinin was infused in seventeen hypertensive patients randomized to treatment with the ACEIs captopril and quinapril or with placebo. Bradykinin caused a significant decrease in mean arterial pressure (MAP) (p = 0.014) and increase in pulse (p <0.001). ACEI significantly potentiated the hemodynamic effect of bradykinin (p <0.05). Although baseline t-PA antigen levels were similar in the ACEI-treated (6.85 ± 0.85 ng/ml) and placebo-treated (7.85 ± 0.68 ng/ml) subjects, bradykinin caused a significant (p <0.01) increase in t-PA antigen levels (to 19.3 ± 8.2) only in the ACEI-treated patients. This increase in t-PA was independent of activation of the sympathetic nervous system. Bradykinin had no effect on PAI-1 antigen levels.These in vivo data suggest that infusion of bradykinin results in an increase in circulating t-PA levels without an effect on PAI-1.
Soluble Adhesion Molecules and Endothelial Cell Damage in HIV Infected Patients
Authors: Seigneur Martine , Constans Joël , Blann Andrew , Renard Martine , Pellegrin Jean Luc , Amiral Jean , Boisseau Michel , Conri Claude 
Published: July 2018

SummaryEndothelial damage is present in HIV infection but our understanding of markers and mechanisms is incomplete. We found increased levels of markers of endothelial cell damage such as von Willebrand factor (vWf), soluble thrombomodulin (sTM) and adhesion molecule E- selectin in 90 subjects seropositive for HIV relative to healthy controls. sTM was strongly raised in those patients with the lowest CD4+ cell count (p <0.001), but levels of vWf increased at each incremental fall in CD4+ cell count and the two indices correlated significantly (r = -0.485, p <0.001). vWf correlated strongly with levels of the inflammatory cytokines tumor necrosis factor (TNF-α) and alpha interferon (IFN-α) but sTM correlated only weakly with IFN-α. We suggest that increased vWf is largely the result of inflammatory stimulus of the endothelium but that sTM is found only in those patients with more severe disease, and so truely represents endothelial damage.
Decrease in Factor VII Coagulant Activity during Percutaneous Transluminal Coronary Angioplasty by Heparin-Mediated Lipolytic Action
Authors: Mukherjee Manjari , Scully Michael F , Kakkar Vijay V , Philippou Helen , Lane David A , Jewitt David 
Published: July 2018

SummaryLevels of factor VII coagulant activity (FVII: C) and two-chain factor Vila antigen (FVIIa: Ag) were measured in ten patients before and up to 6 h after receiving a bolus of heparin during percutaneous transluminal coronary angioplasty (PTCA). A significant and sustained post-heparin fall in the level of FVII: C was observed (approximately 30%) without any change in the level of FVIIa: Ag. The level of tissue factor antigen within the circulation remained unchanged. The observed decrease in FVII: C coincided with a significant decrease in triglyceride levels presumably due to lipoprotein and hepatic lipase released by the heparin. These findings appear to demonstrate a lipid (triglyceride) dependence of FVII: C. Thus, heparin may act indirectly as antithrombotic agent by limiting a lipid-dependent activation of the extrinsic pathway of coagulation.
The Role of the Low-Density Lipoprotein Receptor-Related Protein (LRP) in the Plasma Clearance and Liver Uptake of Recombinant Single-chain Urokinase-type Plasminogen Activator in Rats
Authors: van der Kaaden Marieke E , Rijken Dingeman C , Kar Kruijt J , van Berkel Theo J C , Kuiper Johan 
Published: July 2018

SummaryUrokinase-type plasminogen activator (u-PA) is used as a thrombolytic agent in the treatment of acute myocardial infarction. In vitro, recombinant single-chain u-PA (rscu-PA) expressed in E.coli is recognized by the Low-Density Lipoprotein Receptor-related Protein (LRP) on rat parenchymal liver cells. In this study we investigated the role of LRP in the liver uptake and plasma clearance of rscu-PA in rats. A preinjection of the LRP inhibitor GST-RAP reduced the maximal liver uptake of 125I-rscu-PA at 5 min after injection from 50 to 30% of the injected dose and decreased the clearance of rscu-PA from 2.37 ml/min to 1.58 ml/min. Parenchymal, Kupffer and endothelial cells were responsible for 40, 50 and 10% of the liver uptake, respectively. The reduction in liver uptake of rscu-PA by the preinjection of GST-RAP was caused by a 91 % and 62% reduction in the uptake by parenchymal and Kupffer cells, respectively. In order to investigate the part of rscu-PA that accounted for the interaction with LRP, experiments were performed with a mutant of rscu-PA lacking residues 11-135 (= deltal25- rscu-PA). Deletion of residues 11-135 resulted in a 80% reduction in liver uptake and a 2.4 times slower clearance (0.97 ml/min). The parenchymal, Kupffer and endothelial cells were responsible for respectively 60, 33 and 7% of the liver uptake of 125I-deltal25-rscu-PA. Preinjection of GST-RAP completely reduced the liver uptake of delta 125-rscu-PA and reduced its clearance to 0.79 ml/min. Treatment of isolated Kupffer cells with PI-PLC reduced the binding of rscu-PA by 40%, suggesting the involvement of the urokinase-type Plasminogen Activator Receptor (u-PAR) in the recognition of rscu-PA. Our results demonstrate that in vivo LRP is responsible for more than 90% of the parenchymal liver cell mediated uptake of rscu-PA and for 60% of the Kupffer cell interaction. It is also suggested that u-PAR is involved in the Kupffer cell recognition of rscu-PA.
Autoantibody Selectively Inhibits Binding of von Willebrand Factor to Glycoprotein Ib. Recognition Site Is Located in the A1 Loop of von Willebrand Factor
Authors: Mohri Hiroshi , Yamazaki Etsuko , Suzuki Zekou , Takano Toshikuni , Yokota Shumpei , Okubo Takao 
Published: July 2018

SummaryA 20-year-old man with severe von Willebrand disease recently presented a progressive bleeding tendency, characterized recurrent subcutaneous hemorrhages and cerebral hemorrhage. Mixing and infusion studies suggested the presence of an inhibitor directed against vWF:RCo activity of von Willebrand factor (vWF) without significant inhibition of the FVIII:C. The inhibitor was identified as an antibody of IgG class. The inhibitor inhibited the interaction of vWF in the presence of ristocetin and that of asialo-vWF with GPIb while it partially blocked botrocetin-mediated interaction of vWF to GPIb. The inhibitor reacted with native vWF, the 39/34kDa fragment (amino acids [aa] 480/ 481-718) and the recombinant vWF fragment (MalE-rvWF508-704), but not with Fragment III-T2 (heavy chains, aa 273-511; light chains, aa 674-728). A synthetic peptide (aa 514-542) did not inhibit vWF-inhibitor complex formation. We conclude that this is the first autoantibody of class IgG from human origin that recognizes the sequence in the A1 loop of vWF, resulting in a virtual absence of functional vWF and a concomitant severe bleeding tendency although recognition site is different from the residues 514-542 which is crucial for vWF-GPIb interaction.
Subcutaneous Recombinant Hirudin (HBW 023) Versus Intravenous Sodium Heparin in Treatment of Established Acute Deep Vein Thrombosis of the Legs: a Multicentre Prospective Dose-ranging Randomized Trial
Authors: Schiele François , Lindgaerde Folke , Eriksson Henry , Bassand Jean-Pierre , Wallmark Anders , Hansson Per-Olaf , Grollier Gilles , Sjo Malvin , Moia Marco , Camez Anne , Smyth Vince , Walker Michael ,   for the International Multicentre Hirudin Study Group
Published: July 2018

SummaryThe aim of this multicentre, prospective, randomised, dose-ranging study was to compare the safety and efficacy of subcutaneous recombinant hirudin (HBW 023) against intravenous sodium heparin in acute lower limb deep venous thrombosis (DVT). Patients were randomized to treatment with either HBW 023 or heparin for 5 ±1 days. HBW 023 was given according to body-weight in three dose groups. Thromboembolic disease was assessed by phlebography and ventilation/perfusion (V/Q) scanning on Bay 1 and Day 5±1. One hundred and fifty-five patients were enrolled, of these 121 were evaluable for efficacy analysis. Significantly fewer patients on HBW 023 developed new V/Q abnormalities during the treatment period, (p = 0.006). There was no difference between the groups in thrombus extension or regression, major bleeding complications or serious adverse events. There were significantly fewer findings of new V/Q mismatch after treatment with HBW 023, and anticoagulant control was superior in these patients.
A Comparison of a Moderate with Moderate-high Intensity Oral Anticoagulant Treatment in Patients with Mechanical Heart Valve Prostheses
Authors: Pengo Vittorio , Barbero Fabio , Banzato Alberto , Garelli Elisabetta , Noventa Franco , Biasiolo Alessandro , Zasso Antonella , Volta Sergio Dalla 
Published: July 2018

SummaryBackground. The long-term administration of oral anticoagulants to patients with mechanical heart valve prostheses is generally accepted. However, the appropriate intensity of oral anticoagulant treatment in these patients is still controversial.Methods and Results. From March 1991 to March 1994, patients referred to the Padova Thrombosis Center who had undergone mechanical heart valve substitution at least 6 months earlier were randomly assigned to receive oral anticoagulants at moderate intensity (target INR = 3) or moderate-high intensity (target INR = 4). Principal end points were major bleeding, thromboembolism and vascular death. Minor bleeding was a secondary end-point.A total of 104 patients were assigned to the target 3 group and 101 to the target 4 group; they were followed for from 1.5 years to up 4.5 years (mean, 3 years). Principal end-points occurred in 13 patients in the target 3 group (4 per 100 patient-years) and in 20 patients in the target 4 group (6.9 per 100 patient-years). Major hemorrhagic events occurred in 15 patients, 4 in the target 3 group (1.2 per 100 patient-years) and 11 in the target 4 group (3.8 per 100 patient-years) (p = 0.019). The 12 recorded episodes of thromboembolism, 4 of which consisted of a visual deficit, were all transient ischemic attacks, 6 in the target 3 group (1.8 per 100 patient-years) and 6 in the target 4 group (2.1 per 100 patient- years). There were 3 vascular deaths in each group (0.9 and 1 per 100 patient-years for target 3 and target 4 groups, respectively). Minor bleeding episodes occurred 85 times (26 per 100 patient-years) in the target 3 group and 123 times (43 per 100 patient-years) in the target 4 group (p = 0.001).Conclusions. Mechanical heart valve patients on anticoagulant treatment who had been operated on at least 6 months earlier experienced fewer bleeding complications when maintained on a moderate intensity regimen (target INR = 3) than those on a moderate-high intensity regimen (target INR = 4). The number of thromboembolic events and vascular deaths did not differ between the two groups.
Prediction of Changes in Levels of Haemostatic Variables during Natural Menstrual Cycle and Ovarian Hyperstimulation
Authors: Andersson Ola , Blombäck Margareta , Bremme Katarina , Wramsby Håkan 
Published: July 2018

SummaryTo find if there is a relation between levels of haemostatic variables at low and high hormonal levels (oestradiol and progesterone) in an individual, blood samples were drawn from 12 women repeatedly during one menstrual cycle (Study I) and from 14 women undergoing in vitro fertilization, before hormonal stimulation and daily during the periovu- latory period (Study II). Regression coefficients were calculated between minimum (independent) and maximum (dependent) values in both studies. In Study II highly significant regression coefficients were found between oestradiol minimum (pretreatment) and maximum (mcdian 105 and 4730 pmol/1, respectively) for coagulation factors FVIII, von Willebrand Factor (antigen), FVII (activity and antigen), fibrinogen, protein C, protein S (free), antithrombin, plasminogen and plasminogen activator inhibitor-1; furthermore, between progesterone-minimum at day -3 or -2 (related to ovum pick up) and maximum (median 4.7 and 98 nmol/1, respectively) for FVIII, von Willebrand Factor, FVII (activity and antigen), protein C, protein S (free), and plasminogen. In Study I, where much lower hormonal levels were obtained at maximum (oestradiol median 297 pmol/1 and and progesterone 47 nmol/1), the same pattern was observed especially for FVIII, FX, fibrinogen, plasminogen and plasmin inhibitor. Thus, the concentration of a haemostatic variable at a low oestradiol or progesterone level can predict the level at a high hormonal level.
Activation of the Fibrinolytic System in Patients with Coronary Artery Disease and Hyperfibrinogenemia
Authors: Stein D , Heins M , Schoebel F C , Pels K , Jax T W , Stiegler H , Reinauer H , Strauer B E , Leschke M 
Published: July 2018

SummaryElevated fibrinogen levels as well as an impaired activity of the fibrinolytic system are regarded as important cardiovascular risk factors. To elucidate a potential interrelation between fibrinogen as an indicator of a hypercoagulable state and the endogenous fibrinolytic function hemostatic and rheological as well as lipid parameters were determined in 224 consecutive patients, who underwent elective coronary angiography. In the selected study population of 81 men and 19 women with fibrinogen concentrations either ≥3.5 g/1 (n = 70) or ≤2.5 g/1 (n = 30) hyperfibrinogenemia was found to be significantly associated with increased concentrations of plasmin-α2-antiplasmin complex [PAP [median (25.-75. percentile)], 534 (361-680) μg/l vs. 289 (243-440) μg/1; p <0.001] and tissue plasminogen activator (t-PA) antigen [9 (6-11) μg/1 vs. 8 (5-9) |xg/l; p <0.05] while this association was lost in the subgroup of patients with angiographically normal coronary arteries (n = 26). In addition to these findings fibrinogen was significantly correlated with PAP (r = 0.40, p <0.001; n = 224) and t-PA antigen (r = 0.2, p <0.01; n = 224) after adjustment for age, diabetes mellitus, lipid parameters and leucocyte counts. It can be argued that elevated fibrinogen levels in patients with coronary artery disease are concomitant with an activation of the fibrinolytic system.
The Integrin α2β1 (GPIa/IIa)-I-Domain Inhibits Platelet-Collagen Interaction
Authors: Depraetere H , Wille C , Gansemans Y , Stanssens P , Lauwereys M , Baruch D , De Reys S , Deckmyn H 
Published: July 2018

SummaryThe integrin α2β1 is a major cellular receptor for collagen. The α2subunit contains an ± 200 amino acids inserted domain (I-domain) in the N-terminal region. A certain degree of homology exists between the I-domains found in integrins, collagen and the A-domains of vWF.The α2-I-domain encoding region (aa residues D145 to S334) was obtained by RT-PCR from mRNA of non stimulated human PBL’s. The primers were designed to introduce the necessary restriction sites for cloning of the DNA fragment in frame downstream of the malE gene, as well as a stop codon after the last triplet. The resulting construct pMAL-c2-α2-I allows the expression of the I-domain, fused to the C-terminus of maltose binding protein (mal). The α2-I-mal is purified from the bacterial extract by affinity chromatography on an amylose column.The purified α2-I-mal has been characterized by ELISA’s. The animal bound to immobilised collagen type I in a concentration dependent manner and could be blocked by the functional monoclonal anti-α2β1 antibody 6F1.The interaction of α2-I-mal with collagen furthermore is Mg2+- dependent since the binding was inhibited in the presence of 10 mM EDTA or 10 mM Ca2+ but sustained in the presence of 10 mM Mg2+.Finally, α2-I-mal itself was able to inhibit adhesion of washed platelets to collagen immobilised on a microtiterplate in a dose-dependent manner (α2-I-mal IC50:0.7 μ M) as well as platelet aggregation induced by collagen type I (α2-I-mal IC50: 0.7 μM).With these results we could confirm that the α2-I-domain represents the collagen-binding site of α2β1 and we furthermore could indicate that this domain is able to prevent platelet adhesion to collagen and collagen-induced platelet aggregation, pointing to the primordial role of α2-I-mal and hence of α2β1 in platelet-collagen interaction.
Comparison of Dose Regimens for the Administration of Recombinant Pro-urokinase in a Canine Thrombosis Model
Authors: Burke Sandra E , Lubbers Nathan L , Nelson Richard A , Henkin Jack 
Published: July 2018

SummaryPro-urokinase represents an important addition to the array of thrombolytic drugs currently available for clinical use because of its high clot specificity but distinctly different mechanism compared with that of t-PA. Recombinant pro-urokinase (r-proUK) is a single-chain precursor of high molecular weight urokinase which has been expressed in a mouse myeloma cell line. The present study was conducted to determine the dosing regimen which would produce optimal clot lysis and restoration of blood flow 2 h after treatment with r-proUK, using a dog model of arterial thrombosis. Efficacy was indicated by lysis of a radiolabelled clot which was formed in the heat-damaged femoral arteries of 39 male beagle dogs. The animals were divided into six heparinized treatment groups, each receiving one of five dosing regimens or the vehicle for r-proUK. The total dose (80,000 U/kg) was divided into an initial loading bolus, followed by either a second bolus or by infusions for various time periods, as shown below:It was concluded that optimal clot lysis and restoration of femoral flow was accomplished using a regimen in which 50% of the dose was given as a bolus, followed immediately by the remaining 50% given as a 30 min intravenous infusion (Group 5). At the dose used in this study, r-proUK did not produce degradation of fibrinolytic or hemostatic plasma proteins.