ORBi Open Repository and Bibliography
In may 2007, the ULg's Administrative Board (joined in June 2007 by the FUSAGx) decided to create an institutional repository and defined a strong institutional self-archiving policy to increase the visibility, accessibility and impact of the University's publications (Board's decision).
This decision led to the official launch, in November 2008, of the ORBi platform including both the Academic Bibliography and the Institutional Repository of the Wallonia-Europe University Academy.
Human health sciences => Hematology
Mostrando recursos 601 - 620 de 954
La Thrombinographie : vers une globalisation des tests de la coagulation. - Peters, Pierre; Gothot, André
Thrombin is the key enzyme of coagulation and thrombin generation is the central haemostatic process. Current clotting tests (PT, aPTT) measure the time at which the first fibrin filaments appear after activation of coagulation . Yet, more than 95% of thrombin is generated after clot detection, which underlies the poor sensitivity of usual clotting tests for the detection of many hemorragic or thrombotic diseases. Thrombinography measures the kinetics of thrombin generation and inactivation during ex vivo coagulation, in standardized conditions. Thrombin generation is reduced in hemophiliacs and in patients under anticoagulant treatment. Thrombin activity is raised in hypercoagulable states, such...
Expression and function of the collagen receptor GPVI during megakaryocyte maturation. - Lagrue-Lak-Hal, A H; Debili, N; Kingbury, G; Lecut, Christelle; Le Couedic, J P; Villeval, J L; Jandrot-Perrus, M; Vainchenker, W
In this report, the expression and function of the platelet collagen receptor glycoprotein VI (GPVI) were studied in human megakaryocytes during differentiation and maturation of mobilized blood and cord blood derived CD34(+) cells. By flow cytometry, using an anti-GPVI monoclonal antibody or convulxin, a GPVI-specific ligand, GPVI was detected only on CD41(+) cells including some CD41(+)/CD34(+) cells, suggesting expression at a stage of differentiation similar to CD41. These results were confirmed at the mRNA level using reverse transcription-polymerase chain reaction. GPVI expression was low during megakaryocytic differentiation but increased in the more mature megakaryocytes (CD41(high)). As in platelets, megakaryocyte GPVI...
Human platelet glycoprotein VI function is antagonized by monoclonal antibody-derived Fab fragments. - Lecut, Christelle; Feeney, L A; Kingsbury, G; Hopkins, J; Lanza, F; Gachet, C; Villeval, J-L; Jandrot-Perrus, M
Platelet interactions with adhesive ligands exposed at sites of vascular injury initiate the normal hemostatic response but may also lead to arterial thrombosis. Platelet membrane glycoprotein (GP)VI is a key receptor for collagen. Impairment of GPVI function in mice results in a long-term antithrombotic protection and prevents neointimal hyperplasia following arterial injury. On the other hand, GPVI deficiency in humans or mice does not result in serious bleeding tendencies. Blocking GPVI function may thus represent a new and safe antithrombotic approach, but no specific, potent anti-GPVI directed at the human receptor is yet available. Our aim was to produce accessible...
Severe deficiency of glycoprotein VI in a patient with gray platelet syndrome. - Nurden, Paquita; Jandrot-Perrus, Martine; Combrie, Robert; Winckler, Joelle; Arocas, Veronique; Lecut, Christelle; Pasquet, Jean-Max; Kunicki, Thomas J; Nurden, Alan T
We report a novel case of gray platelet syndrome (GPS) where a severe deficiency of the platelet collagen receptor, glycoprotein (GP) VI, accompanies classical symptoms of a low platelet count and platelets lacking alpha-granules. Dense granules were normally present. Platelet aggregation with collagen was severely decreased, as was the response to convulxin (Cvx), a GPVI agonist. Quantitative analysis of GPVI using fluorescein isothiocyanate (FITC)-Cvx in flow cytometry showed its virtual absence on the patient's platelets. The GPVI deficiency was confirmed using monoclonal antibodies in Western blotting and in immunogold labeling on frozen thin sections where internal pools of GPVI were...
Principal role of glycoprotein VI in alpha2beta1 and alphaIIbbeta3 activation during collagen-induced thrombus formation. - Lecut, Christelle; Schoolmeester, Anne; Kuijpers, Marijke J E; Broers, Jos L V; van Zandvoort, Marc A M J; Vanhoorelbeke, Karen; Deckmyn, Hans; Jandrot-Perrus, Martine; Heemskerk, Johan W M
OBJECTIVE: High-shear perfusion of blood over collagen results in rapid platelet adhesion, aggregation, and procoagulant activity. We studied regulation of alpha2beta1 and alphaIIbbeta3 integrin activation during thrombus formation on collagen. METHODS AND RESULTS: Blockade of glycoprotein (GP) VI by 9O12 antibody or of P2Y purinergic receptors permitted platelet adhesion but reduced aggregate formation, fibrinogen binding, and activation of alpha2beta1 and alphaIIbbeta3, as detected with antibodies IAC-1 and PAC1 directed against activation-dependent epitopes of these integrins. Combined blockade of GPVI and P2Y receptors and thromboxane formation abolished integrin activation but still allowed adhesion of morphologically unstimulated, nonprocoagulant platelets. Exogenous ADP partly...
Fibrillar type I collagens enhance platelet-dependent thrombin generation via glycoprotein VI with direct support of alpha2beta1 but not alphaIIbbeta3 integrin. - Lecut, Christelle; Feijge, Marion A H; Cosemans, Judith M E M; Jandrot-Perrus, Martine; Heemskerk, Johan W M
The role of collagens and collagen receptors was investigated in stimulating platelet-dependent thrombin generation. Fibrillar type-I collagens, including collagen from human heart, were most potent in enhancing thrombin generation, in a way dependent on exposure of phosphatidylserine (PS) at the platelet surface. Soluble, non-fibrillar type-I collagen required pre-activation of integrin alpha2beta1 with Mn2+ for enhancement of thrombin generation. With all preparations, blocking of glycoprotein VI (GPVI) with 9O12 antibody abrogated the collagen-enhanced thrombin generation, regardless of the alpha2beta 1 activation state. Blockade of alpha2beta1 alone or antagonism of autocrine thromboxane A2 and ADP were less effective. Blockade of alphaIIbbeta3 with...
Platelet adhesion receptors do not modulate infarct volume after a photochemically induced stroke in mice. - Frederix, Kim; Chauhan, Anil K; Kisucka, Janka; Zhao, Bing*-Qiao; Hoff, Erik I; Spronk, Henri M H; Ten Cate, Hugo; Wagner, Denisa D
Photochemically induced cerebral infarction has been considered a clinically relevant model for ischemic stroke. We evaluated various transgenic mice to study the role of platelet adhesion molecules in this model. Infarction to the sensorimotoric cortex was induced by erythrosin B and laser light. Infarct volumes were calculated from triphenyltetrazolium chloride stained brain slices. Thrombus formation and vessel leakage were observed in vivo by multiphoton microscopy. Mice mutant in VWF, GPIbalpha, beta3 integrin, and P-selectin did not show any significant differences in infarct volume compared to wild type (WT). This is in contrast to the intraluminal middle cerebral artery occlusion model...
A new method to determine tissue specific tissue factor thrombomodulin activities: endotoxin and particulate air pollution induced disbalance. - Frederix, Kim; Kooter, Ingeborg M; van Oerle, Rene; Fens, Diane; Hamulyak, Karly; Gerlofs-Nijland, Miriam E; Ten Cate, Hugo; Spronk, Henri Mh
ABSTRACT: BACKGROUND: Increase in tissue factor (TF) and loss in thrombomodulin (TM) antigen levels has been described in various inflammatory disorders. The functional consequences of such changes in antigen concentrations in the coagulation balance are, however, not known. This study was designed to assess the consequences of inflammation-driven organ specific functional properties of the procoagulant response. METHODS: Tissue specific procoagulant activity was assessed by adding tissue homogenate to normal human pool plasma and recording of the thrombin generation curve. The new technique was subsequently applied on two inflammation driven animal models: 1) mouse lipopolysaccharide (LPS) induced endotoxemia and 2) spontaneously...
Pulmonary veno-occlusive disease in myeloproliferative disorder. - Willems, Evelyne; Canivet, Jean-Luc; Ghaye, Benoît; de Leval, Laurence; Radermecker, Marc; Preiser, Jean-Charles; Beguin, Yves
The present study reports a case of biopsy-proven pulmonary veno-occlusive disease as a cause of severe pulmonary hypertension in a patient suffering from a chronic myeloproliferative disorder. The pulmonary disease evolved favourably under treatment with defibrotide, a pro-fibrinolytic medication used in hepatic veno-occlusive disease.
Rh D foeto-maternal alloimmunization prophylaxis with anti-D immunoglobulins reviewed in the era of foetal RHD genotyping. - Minon, JM; Gerard, Christiane; Schaaps, Jean-Pierre; Foidart, Jean-Michel
In Belgium, prevention of anti-D immunization is currently based on systematic postnatal prophylaxis associated with targeted antenatal injection in high-risk situations of foeto-maternal haemorrhage.The failures of prevention are mainly due to the non-respect of established guidelines for RhlG prophylaxis, and to spontaneous undetected foetal-maternal haemorrhages without any obvious cause during the third trimester of pregnancy. In order to reduce the rate of residual post-pregnancy anti-D immunization, several countries decided to associate the classical prophylaxis to a routine antenatal anti-D prophylaxis (RAADP) during the 28th or 29th week of gestation. Since a few years, the foetal RHD genotyping in maternal plasma...
Les anticorps monoclonaux en hématologie en 2009 - Bonnet, Christophe; Beguin, Yves; De Prijck, Bernard; Witvrouw, Nancy; Hustinx, Roland; Fillet, Georges
Directed against the CD20 antigen on B lymphocytes, rituximab (MabThera) is now incorporated in the first line therapy of symptomatic follicular as well as diffuse large B cell non-Hodgkin's lymphoma and offers superior response and survival rates. 90Y ibritumomab tiuxetan (Zevalin) combines the specificity of rituximab for the CD20 antigen and the therapeutic effect of β irradiation. Given in monotherapy, it constitutes an interesting alternative therapy for follicular lymphomas in second relapse. Alemtuzumab (MabCampath) recognizes the CD52 antigen and offers encouraging results in chronic lymphocytic leukemia resistant to classical chemotherapy.