bluuebunny/crossref_metadata_2025_split huggingface dataset:
Acute tissue-type plasminogen activator release in human microvascular endothelial cells: The roles of Gαq, PLC-β, IP3 and 5,6-epoxyeicosatrienoic acid
Authors: Muldowney III James , Painter Corrie , Sanders-Bush Elaine , Brown Nancy , Vaughan Douglas 
Published: June 2007

SummaryThe acute physiologic release of tissue-type plasminogen activator (t-PA) from the endothelium is critical for vascular homeostasis. This process is prostacyclin- and nitric oxide (NO)-independent in humans. It has been suggested that calcium signaling and endothelial-derived hyperpolarizing factors (EDHF) may play a role in t-PA release. G-protein-coupled receptor-dependent calcium signaling is typically Gαq -dependent. EDHFs have been functionally defined and in various tissues are believed to be various regioisomers of the epoxyeicosatrienoic acids (EETs). We tested the hypothesis in vitrothat thrombin-stimulated t-PA release from human microvascular endothelial cells (HMECs) is both Gαq - and EDHF-dependent. Conditioned media was harvested following thrombin stimulation, and t-PA antigen was measured by ELISA. Thrombin-induced t-PA release was limited by a membrane-permeable Gαq inhibitory peptide, the PLC-β antagonist U73122, and the IP3 receptor antagonist 2-aminoethoxyphenylborane, while the Gαq agonist Pasteurellatoxin modestly induced t-PA release. The cytochrome P450 (CYP450) inhibitor, miconazole, and the arachidonic acid epoxygenase inhibitor MS-PPOH inhibited thrombin-stimulated t-PA release, while 5,6-EET-methyl ester stimulated t-PA release. The 5,6- and 14,15-EET antagonist, 14,15-epoxyeicosa-5(Z)- enoic acid, inhibited t-PA release at the 100 µM concentration. However, thrombin-stimulated t-PA release was unaffected by the prostacyclin and NO inhibitors ASA and L-NAME, as well as the potassium channel inhibitors TEA, apamin and charybdotoxin. These studies suggest that thrombin-stimulated t-PA release is Gαq-, PLC-β -, IP3 -, and 5,6-EET-dependent while being prostacyclin-, NO- and K + channel-independent in HMECs.
Inhibition of clot formation process by treatment with the lowmolecular-weight heparin nadroparin in patients with carotid artery disease undergoing angioplasty and stenting - A thromboelastography study on whole blood
Authors: Konstantinidis Konstantinos , Gerasimidis Thomas , Verdy Elisabeth , Elalamy Ismail , Samama Michel M. , Gerotziafas Grigoris T. 
Published: June 2007

SummaryLow-molecular-weight heparins (LMWHs) have become the corner stone of antithrombotic treatment but their administration protocol needs to be optimized for certain groups of patients. In this paper, we studied the influence of nadroparin treatment on clot formation process assessed by thromboelastography in patients with carotid artery disease undergoing angioplasty and stenting. Standard thromboelastography assays (in-TEM® and ex-TEM® ) and minimal TF-triggered thromboelastography assay in citrated whole blood were performed in normal volunteers (n=20), in patients with carotid artery disease receiving only antiplatelet treatment (n=30), and in patients undergoing angioplasty receiving nadroparin 5750 anti-Xa IU s.c. twice daily (n=60). Blood samples were collected four hours after a second injection of nadroparin. In a subgroup of LMWH-patients (n=18) blood samples were also obtained prior to first injection of LMWH. Antiplatelet treatment had no effect on any parameter of the thromboelastographic pattern. Nadroparin treatment resulted in significant prolongation of clotting time (CT) and clot formation time (CFT) and significantly reduced α-angle in minimal TF-triggered thromboelastography and 30–38% of nadroparin treated patients had thromboelastographic parameters beyond the normal maximum limit. In-TEM test revealed a significant prolongation of clotting time while ex-TEM was not modified, and 20 to 30% of the patients had thromboelastographic parameters beyond the normal maximum limit. Anti factor-Xa activity in platelet-poor plasma (PPP) was also measured, and statistical analysis showed that prolongation of CFT of minimal TF-triggered TEM was significantly correlated to the levels of anti-Xa activity in patients’ plasma (p=0.04; r2 =0.7). There was no statistical correlation for any other parameter in all tests. In conclusion, the present study shows that nadroparin treatment in patients with carotid artery disease undergoing endovascular procedures induces significant modification of the thrombus kinetics assessed by minimal TF-triggered whole blood thromboelastography. The clinical relevance of these findings has to be evaluated in future studies.
Performance evaluation of the new CoaguChek XS system compared with the established CoaguChek system by patients experienced in INR-self management
Authors: Watzke Herbert , Hasenkam Michael , Schwab Michael , Wolf Tanja , Dovifat Clemens , Völler Heinz , Braun Siegmund 
Published: June 2007

SummaryThe aim of the study was to analyze the concordance of INR values obtained by educated lay users with those obtained by professionals and to determine the imprecision of the new system. The new CoaguChek® XS system was tested in a user study over six weeks at four study centres in Austria, Denmark and Germany. Seventy-five patients receiving oral anticoagulant therapy were enrolled in the study. The INR results in capillary whole blood taken by professionals and by patients using the Coagu- Chek XS system were similar, and the mean relative bias was < 1%. The imprecision of the CoaguChek XS system calculated from duplicate testing is low (<6%) and slightly better than for the established CoaguChek S system. The INR results measured during the home testing phase correlated quite well between the established CoaguChek S system and the new CoaguChek XS system with a mean bias of 0.14 INR. This is a remarkably low bias taking into consideration that more than 30 different test strip lots were applied. A questionnaire was filled out by all patients to assess their personal impression. It revealed that patients were very satisfied with the new system and found it easy to operate. The results demonstrate that the agreement between professional and patient INR results for the new Coagu- Chek XS system was excellent and that INR values can be determined by lay users as well as by professionals. The instrument is very well accepted by the patients and their satisfaction even increased after four weeks practice at home.
Design and characterization of dipetacompinR10H, a dipetalogastin II-derived, classical competitive thrombin inhibitor
Authors: López Mercedes , Nowak Goetz , Bitter Thomas 
Published: June 2007

SummaryThe design of small chimeric thrombin inhibitors based on the structure of dipetalogastin II has been previously described. These proteins are effective inhibitors of thrombin showing slow binding or slow, tight-binding kinetics. We report here about dipetacompinR10H, a new dipetalogastin II-derived chimeric thrombin inhibitor, which exhibits classical competitive kinetics. The dissociation constant Ki of dipetacompinR10H was determined to be 17.1 ± 0.8 pM. In various coagulation assays it showed a comparable anticoagulant activity like r-hirudin and r-dipetalogastin II. DipetacompinR10H’s inhibition of thrombin was specific, since no inhibition of other serine proteases like factor Xa, plasmin, trypsin or chymotrypsin has been observed.
Aspirin-triggered lipoxin A4 blocks reactive oxygen species generation in endothelial cells: A novel antioxidative mechanism
Authors: Nascimento-Silva Vany , Arruda Maria Augusta , Barja-Fidalgo Christina , Fierro Iolanda M. 
Published: June 2007

SummaryLipoxins and their aspirin-triggered carbon-15 epimers have emerged as mediators of key events in endogenous anti-inflammation and resolution. However, the implication of these novel lipid mediators on cardiovascular diseases such as hypertension, atherosclerosis, and heart failure has not been investigated. One of the major features shared by these pathological conditions is the increased production of reactive oxygen species (ROS) generated by vascular NAD(P)H oxidase activation. In this study, we have examined whether an aspirin-triggered lipoxin A4 analog (ATL-1) modulates ROS generation in endothelial cells (EC). Pre-treatment of EC with ATL-1 (1–100 nM) completely blocked ROS production triggered by different agents, as assessed by dihydrorhodamine 123 and hydroethidine. Furthermore, ATL-1 inhibited the phosphorylation and translocation of the cytosplamic NAD(P)H oxidase subunit p47phox to the cell membrane as well as NAD(P)H oxidase activity. Western blot and immunofluorescence microscopy analyses showed that ATL-1 (100 nM) impaired the redox-sensitive activation of the transcriptional factor NF-κB, a critical step in several events associated to vascular pathologies. These results demonstrate that ATL-1 suppresses NAD(P)H oxidase-mediated ROS generation in EC, strongly indicating that lipoxins may play a protective role against the development and progression of cardiovascular diseases.
Immunization of LDL receptor-deficient mice with β2-glycoprotein 1 or human serum albumin induces a more inflammatory phenotype in atherosclerotic plaques
Authors: Dunoyer-Geindre Sylvie , Kwak Brenda R. , Pelli Graziano , Roth Isabelle , Satta Nathalie , Fish Richard J. , Reber Guido , Mach François , Kruithof Egbert K. O. , de Moerloose Philippe 
Published: June 2007

SummaryAntiphospholipid antibodies are a risk factor for venous and arterial thrombosis and may contribute to the development of atherosclerosis. The aim of this study was to investigate whether antibodies to human β2-glycoprotein 1 (β2 GP1), as a model of antiphospholipid antibodies, modify the phenotype of atherosclerotic lesions. LDL receptor-deficient mice were immunized with human β2 GP1, human serum albumin (HSA), or not immunized, and fed a high-cholesterol diet for 14 weeks. Some mice also received pravastatin. Immunization with human β2 GP1 or HSA resulted in formation of autoantibodies recognizing murine β2 GP1 or murine albumin, respectively. We quantified atherosclerotic lesion development and mRNA levels of inflammationassociated proteins in the thoraco-abdominal aorta as well as lesion development, cellular composition and collagen content in the aortic roots. Immunization with β2 GP1 or HSA had no effect on lesion size, but modified the expression in plaque areas of several inflammation-associated proteins. Expression of matrix metalloproteinase-9, tissue factor, interferon-gamma and CD25 was highest in the thoraco-abdominal aorta of β2 GP1-immunized mice, lowest in non-immunized mice and intermediate in HSA-immunized animals. Immunization with β2 GP1, but not HSA, resulted in a lower smooth muscle cell and collagen content of lesions in aortic roots. Statin treatment partially reversed the effects of β2 GP1 immunization. We conclude that immunization with β2 GP1, and to a lesser extent with HSA, leads to modifications in the cellular and protein composition of atherosclerotic plaques, which are associated with a more inflammatory phenotype. Statin treatment partially prevents these changes.
Therapeutic action of tranexamic acid in hereditary haemorrhagic telangiectasia (HHT): Regulation of ALK-1/endoglin pathway in endothelial cells
Authors: Fernandez-L Africa , Garrido-Martin Eva , Sanz-Rodriguez Francisco , Ramirez Jose-Ramon , Morales-Angulo Carmelo , Zarrabeitia Roberto , Perez-Molino Alfonso , Bernabéu Carmelo , Botella Luisa-María 
Published: June 2007

SummaryRecurrent epistaxis is the most frequent clinical manifestation of hereditary haemorrhagic telangiectasia (HHT). Its treatment is difficult. Our objective was to assess the use of tranexamic acid (TA), an antifibrinolytic drug, for the treatment of epistaxis in HHT patients and to investigate in vitro the effects of TA over endoglin and ALK-1 expression and activity in endothelial cells. A prospective study was carried out on patients with epistaxis treated with oral TA in the HHT Unit of Sierrallana Hospital (Cantabria, Spain). Primary cultures of endothelial cells were treated with TA to measure the levels of endoglin and ALK-1 at the cell surface by flow cytometry. RNA levels were also measured by real-time PCR, and the transcriptional effects ofTA on reporters for endoglin, ALK-1 and the endoglin/ALK-1 TGF-beta pathway were assessed. The results showed that the fourteen HHT patients treated orally withTA improved, and the frequency and severity of their epistaxis were decreased. No complications derived from the treatment were observed. Cultured endothelial cells incubated with TA exhibited increased levels of endoglin and ALK-1 at the protein and mRNA levels, enhanced TGF-β signaling, and improved endothelial cell functions like tubulogenesis and migration. In summary, oral administration of TA proved beneficial for epistaxis treatment in selected patients with HHT. In addition to its already reported antifibrinolytic effects, TA stimulates the expression ofALK-1 and endoglin,as well as the activity of the ALK-1/endoglin pathway.
Clot structure modification by fondaparinux and consequence on fibrinolysis: A new mechanism of antithrombotic activity
Authors: Varin Rémi , Mirshahi Shahsultan , Mirshahi Pezhman , Kierzek Gerald , Sebaoun David , Mishal Zohar , Vannier Jean-Pierre , Borg Jeanne Yvonne , Simoneau Guy , Soria Claudine , Soria Jeannette 
Published: June 2007

SummaryFondaparinux is a synthetic pentasaccharide consisting of the minimal sequence of heparin which interacts with antithrombin (AT). It represents a new class of selective factor Xa inhibitors without any antithrombin activity. It has been shown to exhibit potent antithrombotic properties in clinical studies. However, the mechanism of its antithrombotic action has not yet been fully established. In the present study it was shown that fondaparinux, used at pharmacological concentration (500 ng/ml), rendered the clot more susceptible to fibrinolysis induced by t-PA: plasma fibrin clots formed in the presence of fondaparinux and perfused with t-PA were degraded at a faster rate than those formed in the absence of fondaparinux. This fibrinolytic activity of fondaparinux is mainly due to a modification of clot structure characterized by a loose fibrin conformation with less branched fibers and the presence of large pores in comparison to control clots which present a tighter conformation. The difference in fibrin structure was responsible for an increase in clot porosity leading to a better availability of t-PA to the fibrin network. It is related to the decrease in thrombin generation, in an AT-dependent pathway. It was also demonstrated that in the presence of exogenous thrombomodulin, the inhibition of TAFI activation by fondaparinux could contribute, to a lesser extent, to the increased thrombus lysis. The increase in t-PA induced thrombus lysis could contribute to the antithrombotic activity of fondaparinux.
Effect of staphylokinase-derived nonadecapeptide on the activation of plasminogen
Authors: Okada Kiyotaka , Ueshima Shigeru , Matsuno Hiroyuki , Kawao Naoyuki , Okamoto Chikako , Tanaka Masaki , Matsuo Osamu 
Published: June 2007

SummaryStaphylokinase (SAK) expresses plasminogen activator (PA) activity by forming a complex with plasmin. The interaction between the plasmin-SAK complex and plasminogen was investigated using synthesized peptides, which were constructed according to the amino acid sequence of the SAK molecule.A synthetic nonadecapeptide (SAK22–40) corresponding to Glu22-Leu40 by the SAK molecule enhanced the activation of Glu-plasminogen by the plasmin-SAK complex.Analysis of IAsys resonant mirror biosensor showed that SAK22–40 bound to Glu-plasminogen.This binding was completely inhibited by IgG against the B-chain in the plasminogen molecule. But, this binding was not inhibited by IgG against lysine-binding sites (LBS) of the A-chain in the plasminogen molecule. The substitution of Lys35 with Ala in SAK22–40 did not enhance the activation of Glu-plasminogen by the plasmin-SAK complex. When SAK22–40 was administrated in a mouse thrombosis model, earlier recanalization was observed than in mice with vehicle administration. Thus, a newly synthesized peptide, SAK22–40 enhanced Glu-plasminogen activation and induced effective thrombolysis.
Thalidomide and thrombosis
Authors: El Accaoui Ramzi , Shamseddeen Wael , Taher Ali 
Published: June 2007

SummaryWith the increase in the number of reports and trials on the use of thalidomide as a part of the treatment of different medical conditions, particularly multiple myeloma (MM), it was observed that this drug might be associated with an increase in the risk of venous thromboembolic (VTE) events. It was the objective of this study to assess this risk, to check whether it might be affected by the concomitant administration of other medications, specifically dexamethasone, and to study the effect of anticoagulation and anti-platelet medications. A literature search for articles describing the use of thalidomide and the resultant VTE events was performed, and 50 articles were reviewed. A sample consisting of 3,322 patients resembling the above-mentioned studies was designed, and multivariate logistic regression was conducted.While thalidomide, dexamethasone and their combination were found to significantly increase the risk of VTE events among MM patients by 2.6, 2.8 and eight times, respectively, “adequate” anticoagulation significantly reduced the risk. In conclusion, patients receiving thalidomide should be carefully monitored for thromboembolic events,and those receiving concomitantly dexamethasone or other chemotherapy should be followed even more closely. Administering prophylactic doses of low-molecular-weight heparin or warfarin with therapeutic International Normalized Ratio reduces the risk of thromboembolic events among MM patients.
Addition of rituximab to standard therapy improves response rate and progression-free survival in relapsed or refractory thrombotic thrombocytopenic purpura and autoimmune haemolytic anaemia
Authors: von Auer Charis , Huber Christoph , Scharrer Inge , Heidel Florian , Lipka Daniel , Hess Georg 
Published: June 2007

SummaryTreatment of relapsed or refractory autoimmune mediated haemolytic syndromes, such as autoimmune haemolytic anaemia (AIHA) and thrombotic thrombocytopenic purpura (TTP), represents a therapeutic challenge. Here we report on our experience with the monoclonal anti-CD20 antibody rituximab (R) compared to standard treatment in these diseases. Patients with non-familialTTP orAIHA and no underlying malignancy were included in our analysis. Safety and efficacy of R-treatment were compared to results obtained in standard treatment approaches. Altogether, 27 patients were analyzed, comprising 15 patients withTTP and 12 patients with AIHA. The patients’ average age at the time of diagnosis was 54 years. Eleven patients received antibody treatment (8 TTP, 3 AIHA). No acute or late WHO grade III/IV toxicity associated with rituximab was noted. With standard therapy, the overall response rate (ORR) was 66.7% for AIHA and 65.8% for TTP, respectively. For the R-containing regimens the ORR was 100%. In patients with TTP, median progression free survival (PFS) with R-treatment was 3.8 years, as compared to 0.1 years in the standard-treatment group. In patients with AIHA median PFS was not reached for R-containing treatment; all patients are in sustained remissions with a median follow up of 12.5 months. In the absence of prospective trials, our data underline the safety and efficacy of rituximab in relapsed and refractory autoimmune anaemias with favourable response rates and promising long-term progressionfree survival. Therefore, prospective clinical trials evaluating rituximab as salvage- and first-line-therapy are clearly warranted.
Alternatively spliced human tissue factor (asHTF) is not pro-coagulant
Authors: Censarek Petra , Bobbe Anett , Grandoch Maria , Schrör Karsten , Weber Artur-Aron 
Published: June 2007

SummaryIt has been proposed that alternatively-spliced human tissue factor (asHTF) is pro-coagulant. We have evaluated the function of asHTF in a mammalian expression system. Full-length human tissue factor (HTF) and asHTF were cloned from smooth muscle cells and over-expressed in HEK293 cells. As expected, a marked pro-coagulant activity (FX activation, thrombin generation) was observed on the surface, in lysates, and on microparticles from HTF transfected cells. In contrast, no pro-coagulant activity of as HTF was observed.
A novel inhibitor of activated thrombin-activatable fibrinolysis inhibitor (TAFIa) – Part I: Pharmacological characterization
Authors: Zhao Lei , Nagashima Mariko , Vincelette Jon , Sukovich Drew , Li Weiwei , Subramanyam Babu , Yuan Shendong , Emayan Kumar , Islam Imadul , Hrvatin Paul , Bryant Judi , Light David R. , Vergona Ronald , Morser John , Buckman Brad O. , Wang Yi-Xin 
Published: June 2007

SummaryWe have discovered a novel small-molecule (3-phosphinoylpropionic acid) inhibitor of activated thrombin activatable fibrinolysis inhibitor (TAFIa), BX 528, which had an IC50 of 2 nM in an enzymatic assay and 50 nM in an in-vitro clot lysis assay, with 3,500- to 35,000-fold selectivity against other carboxypeptidases, such as CPN, CPZ and CPD, and 5- and 12-fold selectivity against CPE (CPH) and CPB, respectively. At 10 µM, BX 528 had no significant activity (< 50% inhibition or antagonism) in a panel of 137 enzymes and receptors. It had no effects on blood coagulation and platelet aggregation up to 300 and 10 µM, respectively. The plasma half-life following intravenous administration was 0.85 hours in rats and 4.5 hours in dogs. No significant metabolism was detected in human, dog or rabbit hepatic microsomes, and no significant inhibition of cytochrome P450 3A4 and 2D6 up to 30 µM. No cytotoxic or cell proliferative effects were found in three hepatic and renal cell lines up to 300 µM and no mutagenic activity was seen in the Ames II screen. There were no significant hemodynamic effects in rats and dogs up to 100 and 30 mg/kg with peak plasma drug concentrations of ~1,000 and 300 µM, respectively. In an in-vivo complement activation model in guinea pigs, BX 528 showed minimal inhibition of plasma CPN activity up to 60 mg/kg with peak plasma concentrations up to 250 µM. Thus, these data demonstrate that BX 528 is a novel, potent, selective and safe TAFIa inhibitor.
Severe haemophilia B due to a 6 kb factor IX gene deletion including exon 4: Non-homologous recombination associated with a shortened transcript from whole blood
Authors: Hsu Ting-Chang , Nakaya Shelley , Thompson Arthur 
Published: June 2007

SummaryIn genotyping a severe hemophilia B subject, exons 1–3 and 5–8 were normal. Exon 4 did not amplify, suggesting a partial gene deletion. Previously, a French family with an exon 4 deletion had severe haemophilia B with a circulating, dysfunctional factor IX protein missing its first growth factor-like domain; breakpoints were not analyzed. Using a 5’ primer for exon 3 and a 3’ primer for exon 5 fragments, the subject’s factor IX gene amplified a 5 kb fragment whereas 11 kb was predicted, indicating a 6 kb deletion. Restriction endonucleases localized the 3’ intron 4 deletion breakpoint to 1.2 kb 5’ to exon 5. Sequencing through the breakpoints revealed a 5,969 bp deletion that included exon 4 and was accompanied by a 13 bp duplication inserted near the 3’ breakpoint site. Haemophilia was familial; on testing, his mother was confirmed as a heterozygous carrier, whereas his sister was homozygous for the normal, larger fragments. As exons 4 and 5 of the factor IX gene are in frame, this deletion should produce a shortened transcript, missing 114 bp (38 codons from the first growth factor-like domain). Reverse transcription of mRNA prepared from whole blood and PCR identified the shorter cDNA fragment. Western blotting demonstrated a smaller factor IX protein.