bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ca2+-dependent Activation of the 33-kDa Protein Kinase Transmits Thrombin Receptor Signals in Human Platelets
Authors: Ido Masaru , Kato Shinya , Ogawa Hiroyuki , Hayashi Kenji , Komada Yoshihiro , Zhang Xao Li , Sakurai Minoru , Suzuki Koji 
Published: July 2018

SummaryThrombin stimulation induces a dramatic increase in the activity of the 33-kDa serine/threonine kinase (PK33) in human platelets (10). The Arg-Gly-Asp (RGD) peptide, an inhibitor of the thrombin-mediated aggregation of platelets, did not affect the PK33 activation induced by thrombin suggesting that the activation of this kinase occurs independently from platelet aggregation. To identify a potential role of Ca2+ and calmodulin in the regulation of PK33, the effect of several Ca2+/calmodulin inhibitors on the thrombin-induced activation of PK33 was assessed using denaturation/renaturation method. Pretreatment of platelets with EGTA decreased the maximum PK33 activity induced by thrombin. The chelation of both the extra- and the intracellular Ca2+ by EGTA and by acetoxymethyl ester of 5,5′ -dimethyl-bis-(<9-aminophen-oxy) ethane-N,N,N′,N′-tetraacetic acid (BAPTA-AM) decreased further the PK33 activation by thrombin. Preincubation of platelets with the anticalmodulin agent, N-(4-aminobutyl)-5-chloro-2-naphtha-lenesulfonamide (W13), inhibited markedly the activation of PK33 by thrombin, whereas the inactive structural analog N-(4-aminobutyl)-2-naphthalenesulfonamide (W12) and the myosin light chain kinase inhibitor 1 -(5-chloronaphthalene-1 -sulfonyl)-1 H-hexahydro-1,4-diaze-pine (ML9) showed very weak inhibitory effects. Treatment of resting platelets with the calcium ionophore, A23187, activated PK33 in a dose-dependent manner; phorbol 12-myristate 13-acetate enhanced this effect. However, the two foregoing agents did not induce similar degree of PK33 activities as thrombin. These results indicate that the activation of PK33 is independent of the formation of the GPIIb/IIIa-fibrinogen complex and that it might be regulated by a Ca2+-dependent pathway.
Triglyceride Dependence of Factor VII Coagulant Activity in Deep Venous Thrombosis
Authors: Mukherjee Manjari , Dawson Gloria , Sembhi Kuldip , Kakkar Vijay V 
Published: July 2018

SummaryThe effect of incubation of plasma with lipoprotein lipase on factor VII coagulant (FVII: C) activity was examined in 40 patients, 22 male and 18 female, aged 28 to 77 years, with history of venograph-ically proven deep venous thrombosis (DVT). While the mean (± SEM) FVII: C activity of the 40 patients was 100.9 ± 4.1%, 19 patients had FVII: C activity less than 100%, 11 had 100 to 120% activity and 10 patients had greater than 120% FVII:C activity. The mean triglyceride level of all the patients was 84.0 ± 6.5 mg/dl. The FVII: C activity correlated significantly with triglyceride (r = 0.36; n = 40; p = 0.021). There was about 30% average loss of FVII: C activity upon incubation of plasma with lipoprotein lipase. The mean activity loss increased from 23.8% to 31.5% and 42.6% in patients whose FVII:C activity levels were less than 100%, between 100 and 120% and more than 120% respectively, the variation in the means being statistically significant (p <0.001). While according to current opinion, FVII:C activity represents the total FVII mass (FVII plus FVIIa) and activity state, the present findings demonstrate a lipid dependence of FVII: C activity, and raises the possibility of a therapeutic option of controlling FVII: C by controlling triglyceride levels.
A Heparin Cofactor II Mutation (HCII Rimini) Combined with Factor V Leiden or Type I Protein C Deficiency in Two Unrelated Thrombophilic Subjects
Authors: Bernardi F , Legnani C , Micheletti F , Lunghi B , Ferraresi P , Palareti G , Biagi R , Marchetti G 
Published: July 2018

Summary305 patients with juvenile thromboembolic episodes were screened for the presence of heparin cofactor II deficiency. The heterozygous deletion of two bases was found in the exon 5 of the heparin cofactor II gene in two unrelated patients, very likely due to a founder effect. This molecular lesion, causing a frameshift and elongated translation, affects the core of the molecule and should cause the complete unfolding of the protein, which is in accordance with the observed type I deficiency. The corresponding region of antithrombin III gene is affected by a cluster of frameshift mutations suggesting that heparin cofactor II and antithrombin III could share similar mutational patterns.The heparin cofactor II gene alteration was associated with, in one patient, the factor V Leiden mutation and, in the other, type I protein C deficiency. The tracing of the single defects in several family members indicated that the mutations became clinically manifest only when present in the doubly heterozygous condition. This study provides two examples, based on molecular findings, of the interplay of risk factors which is potentially useful to define a role for heparin cofactor II deficiency in inherited thrombophilia.
Risk Factor Profiles in Patients with Different Clinical Manifestations of Venous Thromboembolism: A Focus on the Factor V Leiden Mutation
Authors: Manten Bert , Westendorp Rudi G J , Koster Ted , Reitsma Pieter H , Rosendaal Frits R 
Published: July 2018

Summary
Background. Patients with venous thromboembolic disease may present with different clinical manifestations. Factor V Leiden mutation leading to resistance to activated protein C is associated with a sevenfold increased risk for presenting with deep-vein thrombosis. It is not yet established whether carriers of the mutation have a similarly increased risk for manifesting with pulmonary embolism.
Methods. From an Anticoagulation Clinic monitoring coumarin therapy, a consecutive series of patients with a first thromboembolic event (objectively proven by current radiological methods) were enrolled. All patients were interviewed and blood was drawn for geno-typing. From the hospital charts and the personal interview, information was obtained on acquired risk factors and the signs and symptoms on hospital admission.
Results. 45 patients presented with symptoms of pulmonary embolism only, 211 had only symptoms of deep-vein thrombosis whereas 23 had clinical features of both. In about half of the patients acquired risk factors for venous thromboembolism were present which did not differ between the three groups of patients. Recent surgery had been performed more often in patients presenting with pulmonary embolism than in other patients (33.3% vs. 18.5%, p <0,05). Factor V Leiden was present in 9% of the patients presenting with pulmonary embolism (relative risk: 3.3 95% Cl: 1.0-10.6) and 17% of the patients presenting with deep-vein thrombosis (relative risk: 6.9 95% Cl: 3.6-12.8). The prevalence of factor V Leiden was intermediate in patients with both clinical characteristics.
Conclusion. These data suggest that patients with venous thromboembolism have different clinical presentation depending on the risk factor profile. Factor V Leiden may preferentially lead to manifest deep-vein thrombosis. Differences in structure of venous thrombi could underlie differences in embolic tendency.
Plasmin Is a Specific Stimulus of the 5-Lipoxygenase Pathway of Human Peripheral Monocytes
Authors: Weide Ingo , Tippler Bettina , Syrovets Tatjana , Simmet Thomas 
Published: July 2018

SummaryThe objective of this study was to characterize the plasmin-induced stimulation of leukotriene (LT) B4 biosynthesis in human peripheral monocytes (PM). Plasmin up to 175 × 10-3 CTA U/ml triggers a concentration-dependent release of 5-lipoxygenase-derived LTB4 while release of the cyclooxygenase products thromboxane (TX) B2 and prostaglandin (PG) E2 remained unaffected. The stimulatory effect appeared to be specific in as much as 1) it was found in PM, but not in polymorphonuclear neutrophils (PMN), 2) it requires the lysine binding sites of plasmin molecule since it was inhibited by the lysine analogues 6-aminohexanoic acid (6-AHA) and trans-4(aminometh-yl)cyclohexane-l-carboxylic acid (t-AMCA), 3) the intact catalytic center of plasmin is required since neither plasminogen nor catalytic center-blocked plasmin share the stimulatory effect of active plasmin, 4) other serine proteases such as a-chymotrypsin, human neutrophil elastase and cathepsin G did not stimulate release of detectable amounts of LTB4 from PM. In addition, catalytic center-blocked plasmin antagonized the stimulatory effect of active plasmin. Plasmin-mediated monocyte activation apparently proceeds via a pertussis toxin-sensitive G protein. Plasmin did not increase inositol (1,4,5) trisphosphate levels, but a time- and concentration-dependent stimulation of cyclic GMP formation was observed. The data show that plasmin is a specific stimulus for human peripheral monocytes. Plasmin may be an important link between the coagulation cascade and inflammatory reactions.
Expression of Plasminogen Activator Inhibitor 2 in the Adult and Embryonic Mouse Tissues
Authors: Kawata Yoichi , Mimuro Jun , Kaneko Munekiyo , Shimada Kazuyuki , Sakata Yoichi 
Published: July 2018

SummaryWe have studied the expression of plasminogen activator inhibitor 2 (PAI-2) in the adult mouse and during embryonic development using immunohistochemistry and the polymerase-chain reaction. Mouse PAI-2 mRNA was mainly expressed in the skin, bone-marrow, spleen, lung, thymus, and urinary bladder. Immunohistochemical studies suggested that PAI-2 was synthesized in macrophages and epithelial cells such as skin epithelial cells, transitional cells of the urinary bladder, and mesothelial cell of peritoneum and pleura. PAI-2 mRNA and antigen expression was observed only in the skin of 15 day-old mouse embryos. These data suggest that PAI-2 may play a role in protecting the mouse embryo from the protease attack in the amniotic fluid and also in maintaining and/or protecting the structure of various surfaces in the mouse.
HLA Class II Profile: A Weak Determinant of Factor VIII Inhibitor Development in Severe Haemophilia A
Authors: Hay C R M , Oilier W , Pepper L , Cumming A , Keeney S , Goodeve A C , Colvin B T , Hill F G H , Preston F E , Peake I R ,   UKHCDO Inhibitor Working Party
Published: July 2018

SummaryThe risk of developing factor VIII inhibitor antibodies in haemophilia A may relate both to factor VIII genotype and genes within the HLA complex known to influence immune response. We investigated a cohort of 176 patients with severe haemophilia A and with either high-level inhibitors (>10BU/ml) or with no history of an inhibitor, stratified according to the presence or absence of the factor VIII gene intron 22 inversion.HLA DRB1, DQA1 and DQB1 polymorphisms were determined by PCR. HLA frequencies from 137 United Kingdom controls were used for comparison. HLA phenotype frequency differences, expressed as odds ratios with 95% confidence intervals were as follows: HLA- DRB*1501, DQB 1*0602 and DQA1*0102 were all increased in frequency in patients with inhibitors, only DQA1*0102 reaching statistical significance (OR 2.7,1.2-5.9). These alleles form part of an established HLA haplotype. The frequencies of HLA-DRB 1*1501, DQB1*0602 and DQA1*0102 were particularly raised in patients with inhibitors and a factor VIII gene intron 22 inversion, although again only DQA1*0102 achieved significance (OR 3.1, 1.0-10.1). The frequency of DRB 1*01, DQB 1 *0501, DQA 1*0101 were also increased in inhibitor patients lacking the intron 22 inversion although this failed to achieve statistical significance. This data suggests that HLA class II profile constitutes a weak risk factor for developing inhibitor antibodies to factor VIII. This may be more pronounced in patients with an intron 22 inversion.
A Novel Missense Mutation in the Endoglin Gene in Hereditary Hemorrhagic Telangiectasia
Authors: Yamaguchi Hiroshi , Azuma Hiroyuki , Shigekiyo Toshio , Inoue Hideo , Saito Shiro 
Published: July 2018

SummaryHereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disorder characterized by multisystem vascular dysplasia and recurrent hemorrhage. Recent investigation has mapped one of the responsible genes for HHT to chromosome 9q33-q34; subsequently, nine different mutations have been identified in the endoglin gene, which encodes a transforming growth factor β(TGF-β) binding protein, in nine unrelated families with HHT. We examined the endoglin gene in a Japanese patient with HHT and her family members. Using PCR-SSCP. analysis followed by sequencing, we identified a C to A missense mutation in exon 4 which changed an Ala160 codon(GCT) to an Asp160 codon (GAT). Since this mutation destroys one of three Fnu4H I sites in exon 4, the Fnu4H I digestion patterns of the PCR-amplified exon 4 fragments from each family member were analyzed. In affected members, the restriction patterns were all consistent with a phenotype of HHT. PCR-amplified exon 4 fragments from 150 normal individuals were also analyzed by allele-specific oligonucleotide hybridization analysis. As a result, the mutation was not found in any of them. We conclude that the C to A mutation in exon 4 of the endoglin gene in this proband is responsible for the occurrence of HHT in this family.
Molecular Characterization of a Type I Quantitative Factor V Deficiency in a Thrombosis Patient that Is “Pseudo Homozygous” for Activated Protein C Resistance
Authors: Guasch Joan F , Lensen Ruud P M , Bertina Rogier M 
Published: July 2018

SummaryResistance to activated protein C (APC), which is associated with the FV Leiden mutation in the large majority of the cases, is the most common genetic risk factor for thrombosis. Several laboratory tests have been developed to detect the APC-resistance phenotype. The result of the APC-resistance test (APC-sensitivity ratio, APC-SR) usually correlates well with the FV Leiden genotype, but recently some discrepancies have been reported. Some thrombosis patients that are heterozygous for FV Leiden show an APC-SR usually found only in homozygotes for the defect. Some of those patients proved to be compound heterozygotes for the FV Leiden mutation and for a type I quantitative factor V deficiency. We have investigated a thrombosis patient characterized by an APC-SR that would predict homozygosity for FV Leiden. DNA analysis showed that he was heterozygous for the mutation. Sequencing analysis of genomic DNA revealed that the patient also is heterozygous for a G5509→A substitution in exon 16 of the factor V gene. This mutation interferes with the correct splicing of intron 16 and leads to the presence of a null allele, which corresponds to the “non-FV Leiden” allele. The conjunction of these two defects in the patient apparently leads to the same phenotype as observed in homozygotes for the FV Leiden mutation.
Factor V Leiden Is Not Common in Children with Portal Vein Thrombosis
Authors: Seixas C A , Hessel G , Ribeiro C C , Arruda V R , Annichino-Bizzacchi J M 
Published: July 2018

SummaryPortal vein thrombosis (PVT) is a rare condition affecting both children and adults, and occurs in association with a wide variety of clinical situations. On the other hand, the development of PVT in patients under these situations indicates that other contributing factors could be envolved. Recently a missense mutation in the factor V gene (1691G→A), known as factor V Leiden, has been identified and results in abnormal factor V product, resistant to proteolytic inactivation by activated protein C and thus predisposes to thrombosis. This study was carried out to verify if children with PVT have an increase in frequency of factor V Leiden. Allele-specific restriction analysis and single strand conformational polymorphism (SSCP) were used to test for factor V Leiden in 20 children with PVT and 64 normal children. None of the PVT children were heterozygous or homozygous for the factor V Leiden, and one control child was heterozygous. This study demonstrates that factor V Leiden is not common in children with PVT, and is not a prerequisite for this thrombotic event.
Reliability of Five Rapid D-Dimer Assays Compared to ELISA in the Exclusion of Deep Venous Thrombosis
Authors: Janssen M C H , Heebels A E , de Metz M , Verbruggen H , Wollersheim H , Janssen S , Schuurmans M M J , Nováková I R O 
Published: July 2018

SummaryStudies measuring the fibrin degradation product D-Dimer (DD) using enzyme-linked immunosorbent assays (ELISA) in patients with venographically proven deep venous thrombosis (DVT) suggest that it is possible to exclude DVT when DD level is below a certain cut-off level. However, ELISA methods are time-consuming and not available in all laboratories. Different rapid latex-agglutination assays have been investigated, but their sensitivity is considerably lower.In the present study we compared the value of four novel latex DD tests (Tinaquant®, Minutex®, Ortho® and SimpliRed®) and one rapid ELISA (VIDAS®) to a classical ELISA DD assay (Organon Mab Y18®) in 132 patients suspected of DVT.The VIDAS®, a new quantitative automated ELISA, had a sensitivity of 100% and a negative predictive value of 100% for both proximal and distal DVT at a cut-off level of 500 ng/ml. The Tinaquant® assay, a new quantitative latex method, had a sensitivity of 99% and a negative predictive value of 93% for both proximal and distal DVT at a cut-off level of 500 ng/ml. For proximal DVT only, both assays had a sensitivity and negative predictive value of 100%. VIDAS® and Tinaquant® correlated well with ELISA (correlation of r = 0.96 and r = 0.98 respectively). Sensitivities of the semi-quantitative latex assays Minutex®, Ortho® and SimpliRed® were considerably lower (77%, 51 % and 61 % respectively).These results suggest that VIDAS® and Tinaquant® may be used instead of ELISA DD in the exclusion of DVT. Tinaquant® can be performed within 20 min and VIDAS® within 35 min. Both assays might be used as a routine screening test and should be evaluated in large clinical management studies.
Massive Fibrin Formation with Consecutive Impairment of Fibrinolysis in Patients with Out-of-Hospital Cardiac Arrest
Authors: Gando Satoshi , Kameue Takashi , Nanzaki Satoshi , Nakanishi Yoshimi 
Published: July 2018

SummaryHypoxia and ischaemia influence blood coagulation and fibrinolysis. This study has been made to determine whether human cardiopulmonary arrest causes fibrin formation and reduction of fibrinolysis. Serial levels of fibrinopeptide A (FPA), fibrinopeptide Bβ15-42 (FPBβ15-42), D-dimer, tissue plasminogen activator antigen concentration (t-PA antigen), t-PA activity, plasminogen activator inhibitor-1 antigen concentration (PAI-1 antigen), and PAI-1 activity were determined in 63 patients with out-of-hospital cardiopulmonary arrest. In the resuscitated patients, the markedly elevated FPA (194.8 ± 54.2 ng/ml) at the beginning of cardiopulmonary resuscitation (CPR) significantly decreased to 32.4 ± 9.1 ng/ml at 24 h after admission (p <0.01), however, this was still about 20 times that of the normal controls. FPBβ15-42 and D-dimer increased from the start of CPR to 60 min (189.3 ± 97.4 ng/ml; p <0.01 and 7726 ± 3556 ng/ml; p <0.001, respectively), and then decreased at 24 h after arrival at the Emergency Department (40.4 ±11.1 ng/ml and 5434 ± 1049 ng/ml, respectively). At 30 min after arrival, FPA and FPBβ15-42 significantly differed between the resuscitated patients and the patients who died (p <0.001 and P <0.05, respectively). Although t-PA antigen and t-PA activity was elevated at the time of arrival, 24 h thereafter, no t-PA activity was detected. At 24 h after admission, PAI-1 antigen and PAI-1 activity were significantly increased (472.2 ± 145.5 ng/ml; p <0.001 and 103.6 ± 36.1 IU/ml; p <0.001, respectively). In conclusion, during and after CPR in patients with out-of-hospital cardiac arrest, massive fibrin generation with consecutive impairment of fibrinolysis were observed. These fibrin-mediated events may have some role in the derangement of vital organ function after cardiac arrest.
Recombinant, B-domain Deleted Factor VIII (r-VIII SQ): Pharmacokinetics and Initial Safety Aspects in Hemophilia A Patients
Authors: Fijnvandraat K , Berntorp E , ten Cate J W , Johnsson H , Peters M , Savidge G , Tengborn L , Spira J , Stahl C 
Published: July 2018

SummaryThe pharmacokinetics of a second-generation recombinant B-domain deleted factor VIII (FVIII) preparation (r-VIII SQ) were studied in 36 patients with severe hemophilia A. In contrast to full-length recombinant FVIII, no albumin needs to be added to stabilize the final formulation of this B-domain deleted FVIII preparation.The in vivo recovery and half-life of r-VIII SQ were similar to those of plasma-derived (pd) FVIII (mean half-life of r-VIII SQ, 11.7 h). The volume of distribution and clearance were slightly, but significantly, higher for r-VIII SQ than for pdFVIII (p<0.05). Peak plasma levels of FVIII were consistently related to the administered dose of r-VIII SQ (r = 0.94, p<0.0001). The pharmacokinetic profile of r-VIII SQ remained essentially unchanged in a dose range of 25-100 IU/kg body weight and could be reproduced after repeated doses. r-VIII SQ was well tolerated.In conclusion, deletion of the B-domain of FVIII does not influence its in vivo pharmacokinetics.
Production Method Affects the Pharmacokinetic and Ex Vivo Biological Properties of Low Molecular Weight Heparins
Authors: Brieger David , Dawes Joan 
Published: July 2018

SummaryLow molecular weight (LMW) heparins have prolonged circulating half-lives relative to unfractionated heparin, but the rates of plasma clearance differ between different LMW preparations. To determine the impact of method of production on their pharmacokinetic and ex vivo biological properties, two LMW heparins of similar molecular weight distribution, Logiparin and Fragmin, were radiolabelled with 125I, administered intravenously with 4 mg/kg of carrier drug into rabbits, and the circulating radiolabelled material and anti-Xa activity were analysed by size exclusion chromatography and affinity for antithrom#bin and Polybrene. Following administration of Logiparin, the anti-Xa amidolytic activity was eliminated with the same half-life as the anti#thrombin-binding radiolabel and was not neutralised by antibody against tissue factor pathway inhibitor (TFPI). Larger molecules were cleared preferentially and were no longer detectable 8 h post injection. These findings resemble those we have previously described for Enoxaparin. After Fragmin administration the antithrombin binding radiolabel was cleared more rapidly than the anti-Xa activity, and at late times after injection a significant amount of this activity was neutralised by antibody against TFPI. Sulphated radiolabel was eliminated with a similar half-life to the anti-Xa activity and sulphated molecules >6000 Da remained in the circulation 8 h after administra#tion. Fragmin, unlike Logiparin and Enoxaparin, has no negatively charged sulphamino group at the reducing end of the molecule. We sug#gest that this minimises cellular interaction and protects the larger molecules from elimination. They remain in the circulation, contributing to anti-Xa activity by binding TFPI. Thus the method of production of LMW heparins may significantly influence their pharmacokinetic properties and circulating anticoagulant activities.