The Effect Of Iomeprol On Platelet Aggregation And Potential Risk Of Thrombogenecity

10.5580/2c44 ◽  
2012 ◽  
Vol 8 (1) ◽  
Keyword(s):  
Platelet Aggregation ◽  
Potential Risk

Fine Structure of Platelet Interaction with a New Microcrystalline Collagen Preparation

1974 ◽  
Vol 32 ◽  
pp. 58-59
Author(s):  
W. H. Zucker ◽  
R. G. Mason
Keyword(s):  
Fine Structure ◽  
Platelet Aggregation ◽  
Hydrochloric Acid ◽  
Whole Blood ◽  
Platelet Adhesion ◽  
Hemostatic Agent ◽  
Native Collagen ◽  
Fibrillar Morphology ◽  
Clinical Interest ◽  
New Form

Platelet adhesion initiates platelet aggregation and is an important component of the hemostatic process. Since the development of a new form of collagen as a topical hemostatic agent is of both basic and clinical interest, an ultrastructural and hematologic study of the interaction of platelets with the microcrystalline collagen preparation was undertaken.In this study, whole blood anticoagulated with EDTA was used in order to inhibit aggregation and permit study of platelet adhesion to collagen as an isolated event. The microcrystalline collagen was prepared from bovine dermal corium; milling was with sharp blades. The preparation consists of partial hydrochloric acid amine collagen salts and retains much of the fibrillar morphology of native collagen.

Pulmonary emboli due to venous aneurysm of extremities

VASA ◽  
2011 ◽  
Vol 40 (4) ◽  
pp. 327-332 ◽  
Author(s):  
Gabrielli ◽  
Rosati ◽  
Vitale ◽  
Millarelli ◽  
Siani ◽  
...  
Keyword(s):  
Pulmonary Embolism ◽  
Surgical Resection ◽  
Potential Risk ◽  
Acute Pulmonary Embolism ◽  
Prophylactic Surgery ◽  
Venous Aneurysm ◽  
Pulmonary Emboli ◽  
Thromboembolic Events ◽  
Thromboembolic Complications ◽  
Risk Patients

Venous aneurysms are uncommon but they can have devastating consequences, including pulmonary embolism, other thromboembolic events and death. We report six cases of venous aneurysm of the extremities, in which the first sign of presence was acute pulmonary embolism. Surgical resection is recommended whenever possible. Our experience suggests that prophylactic surgery is cautiously recommended for low-risk patients with venous aneurysms of the abdomen and strongly recommended for extremity deep and superficial venous aneurysms for their potential risk of developing thromboembolic complications despite adequate anticoagulation. Other venous aneurysms should be excised only if they are symptomatic or enlarging.

Transmyocardial Laser Revascularisation - A Potential Risk in Acute Situation?

Swiss Surgery ◽  
2000 ◽  
Vol 6 (2) ◽  
pp. 65-68
Author(s):  
Mueller ◽  
Tevaearai ◽  
Genton ◽  
Bettex ◽  
von Segesser
Keyword(s):  
Potential Risk ◽  
Transmyocardial Laser Revascularisation ◽  
Analyse Morphométrique

Les effets morphologiques et fonctionnels de la revascularisation transmyocardique au laser (RTML) sont analysés en conditions aiguës sur un modèle porcin. La paroi latérale du ventricule gauche de 15 porcs (poids moyen: 73 +/- 4kg) a été percée de 10 canaux laser (laser: Ho-YAG; longueur d'onde: 2.1 u, diamètre de la sonde: 1.75 mm). Une échocardiographie a été effectuée avant, ainsi que 5 min et 30 min après la procédure. Les paramètres échocardiographiques ont été enregistrés en court axe à la hauteur des canaux laser. Ils comprenaient la fraction d'éjection, la fraction de raccourcissement et la motilité segmentaire de la région lasérisée (échelle de 0 à 3: 0 = normal, 1 = hypokinésie, 2 = akinésie, 3 = dyskinésie). Après sacrifice de l'animal, la région lasérisée a été coupée dans un plan perpendiculaire aux canaux pour histologie et analyse morphométrique. Après 5 min, tous les index échocardiographiques ont montré une aggravation significative par rapport aux valeurs de base (p < 0.01). Après 30 min, plus aucun des paramètres ne présentait de variation significative par rapport aux valeurs de base. La surface de section des lésions mesurait 8.8 +/- 2.4 mm2 soit plus du triple de celle de la sonde laser elle-même (p < 0.01). En conditions aiguës, les lésions dues à la sonde de RTML sont nettement plus grande que la sonde elle-même et entraînent une baisse transitoire de la contractilité segmentaire sur un coeur sain. Ces résultats suggèrent que la RTML doit être utilisée avec prudence en clinique chez les patients avec une mauvaise fonction ventriculaire.

Inflammatory process and virgin olive oil phenols: modulation of platelet aggregation and metalloprotease-9 expression in monocytes

Planta Medica ◽  
2008 ◽  
Vol 74 (09) ◽  
Author(s):  
M Dell'Agli ◽  
R Fagnani ◽  
G Galli ◽  
O Maschi ◽  
E de Fabiani ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Olive Oil ◽  
Inflammatory Process ◽  
Virgin Olive Oil

Platelet Activation and Aggregation Induced by Recombinant von Willebrand Factors Reproducing Four Type 2B von Willebrand Disease Missense Mutations

1998 ◽  
Vol 79 (01) ◽  
pp. 211-216 ◽  
Author(s):  
Lysiane Hilbert ◽  
Claudine Mazurier ◽  
Christophe de Romeuf
Keyword(s):  
Platelet Aggregation ◽  
Platelet Activation ◽  
Von Willebrand Disease ◽  
Platelet Glycoprotein ◽  
Missense Mutations ◽  
Inhibit Platelet Aggregation ◽  
Wild Type ◽  
A1 Domain ◽  
Von Willebrand ◽  
Willebrand Factor

SummaryType 2B of von Willebrand disease (vWD) refers to qualitative variants with increased affinity of von Willebrand factor (vWF) for platelet glycoprotein Ib (GPIb). All the mutations responsible for type 2B vWD have been located in the A1 domain of vWF. In this study, various recombinant von Willebrand factors (rvWF) reproducing four type 2B vWD missense mutations were compared to wild-type rvWF (WT-rvWF) for their spontaneous binding to platelets and their capacity to induce platelet activation and aggregation. Our data show that the multimeric pattern of each mutated rvWF is similar to that of WT-rvWF but the extent of spontaneous binding and the capacity to induce platelet activation and aggregation are more important for the R543Q and V553M mutations than for the L697V and A698V mutations. Both the binding of mutated rvWFs to platelets and platelet aggregation induced by type 2B rvWFs are inhibited by monoclonal anti-GPIb and anti-vWF antibodies, inhibitors of vWF binding to platelets in the presence of ristocetin, as well as by aurin tricarboxylic acid. On the other hand, EDTA and a monoclonal antibody directed against GPIIb/IIIa only inhibit platelet aggregation. Furthermore, the incubation of type 2B rvWFs with platelets, under stirring conditions, results in the decrease in high molecular weight vWF multimers in solution, the extent of which appears correlated with that of plasma vWF from type 2B vWD patients harboring the corresponding missense mutation. This study supports that the binding of different mutated type 2B vWFs onto platelet GPIb induces various degrees of platelet activation and aggregation and thus suggests that the phenotypic heterogeneity of type 2B vWD may be related to the nature and/or location of the causative point mutation.

Difference of [Ca2+]i Movements in Platelets Stimulated by Thrombin and TRAP: the Involvement of αIIbβ3-Mediated TXA2 Synthesis

1998 ◽  
Vol 79 (06) ◽  
pp. 1184-1190 ◽  
Author(s):  
Yoshiaki Tomiyama ◽  
Shigenori Honda ◽  
Kayoko Senzaki ◽  
Akito Tanaka ◽  
Mitsuru Okubo ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Fibrinogen Binding ◽  
Adp Release ◽  
The Difference ◽  
Txa2 Receptor Antagonist ◽  
High Level ◽  
Inhibition Studies ◽  
Peak Increase ◽  
Second Peak ◽  
Assay Conditions

SummaryThis study investigated the difference of [Ca2+]i movement in platelets in response to thrombin and TRAP. The involvement of αIIbβ3 in this signaling was also studied. Stimulation of platelets with thrombin at 0.03 U/ml caused platelet aggregation and a two-peak increase in [Ca2+]i. The second peak of [Ca2+]i, but not the first peak was abolished by the inhibition of platelet aggregation with αIIbβ3 antagonists or by scavenging endogenous ADP with apyrase. A cyclooxygenase inhibitor, aspirin, and a TXA2 receptor antagonist, BM13505, also abolished the second peak of [Ca2+]i but not the first peak, although these regents did not inhibit aggregation. Under the same assay conditions, measurement of TXB2 demonstrated that αIIbβ3 antagonists and aspirin almost completely inhibited the production of TXB2. In contrast to thrombin-stimulation, TRAP caused only a single peak of [Ca2+]i even in the presence of platelet aggregation, and a high level of [Ca2+]i increase was needed for the induction of platelet aggregation. The inhibition of aggregation with αIIbβ3 antagonists had no effect on [Ca2+]i change and TXB2 production induced by TRAP. Inhibition studies using anti-GPIb antibodies suggested that GPIb may be involved in the thrombin response, but not in the TRAP. Our findings suggest that low dose thrombin causes a different [Ca2+]i response and TXA2 producing signal from TRAP. Endogenous ADP release and fibrinogen binding to αIIbβ3 are responsible for the synthesis of TXA2 which results in the induction of the second peak of [Ca2+]i in low thrombin- but not TRAP-stimulated platelets.

Functional Characterization of PM6/13, a β3-specific (GPIIIa/CD61) Monoclonal Antibody that Shows Preferential Inhibition of Fibrinogen Binding over Fibronectin Binding to Activated Human Platelets

1998 ◽  
Vol 79 (01) ◽  
pp. 177-185 ◽  
Author(s):  
Ashia Siddiqua ◽  
Michael Wilkinson ◽  
Vijay Kakkar ◽  
Yatin Patel ◽  
Salman Rahman ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Platelet Aggregation ◽  
Platelet Rich Plasma ◽  
Functional Characterization ◽  
Human Platelets ◽  
Western Blots ◽  
Activated Platelets ◽  
Reducing Conditions ◽  
Fibronectin Binding

SummaryWe report the characterization of a monoclonal antibody (MAb) PM6/13 which recognises glycoprotein IIIa (GPIIIa) on platelet membranes and in functional studies inhibits platelet aggregation induced by all agonists examined. In platelet-rich plasma, inhibition of aggregation induced by ADP or low concentrations of collagen was accompanied by inhibition of 5-hydroxytryptamine secretion. EC50 values were 10 and 9 [H9262]g/ml antibody against ADP and collagen induced responses respectively. In washed platelets treated with the cyclooxygenase inhibitor, indomethacin, PM6/13 inhibited platelet aggregation induced by thrombin (0.2 U/ml), collagen (10 [H9262]g/ml) and U46619 (3 [H9262]M) with EC50 = 4, 8 and 4 [H9262]g/ml respectively, without affecting [14C]5-hydroxytryptamine secretion or [3H]arachidonate release in appropriately labelled cells. Studies in Fura 2-labelled platelets revealed that elevation of intracellular calcium by ADP, thrombin or U46619 was unaffected by PM6/13 suggesting that the epitope recognised by the antibody did not influence Ca2+ regulation. In agreement with the results from the platelet aggregation studies, PM6/13 was found to potently inhibit binding of 125I-fibrinogen to ADP activated platelets. Binding of this ligand was also inhibited by two other MAbs tested, namely SZ-21 (also to GPIIIa) and PM6/248 (to the GPIIb-IIIa complex). However when tested against binding of 125I-fibronectin to thrombin stimulated platelets, PM6/13 was ineffective in contrast with SZ-21 and PM6/248, that were both potent inhibitors. This suggested that the epitopes recognised by PM6/13 and SZ-21 on GPIIIa were distinct. Studies employing proteolytic dissection of 125I-labelled GPIIIa by trypsin followed by immunoprecipitation with PM6/13 and analysis by SDS-PAGE, revealed the presence of four fragments at 70, 55, 30 and 28 kDa. PM6/13 did not recognize any protein bands on Western blots performed under reducing conditions. However Western blotting analysis with PM6/13 under non-reducing conditions revealed strong detection of the parent GP IIIa molecule, of trypsin treated samples revealed recognition of an 80 kDa fragment at 1 min, faint recognition of a 60 kDa fragment at 60 min and no recognition of any product at 18 h treatment. Under similar conditions, SZ-21 recognized fragments at 80, 75 and 55 kDa with the 55kDa species persisting even after 18 h trypsin treatment. These studies confirm the epitopes recognised by PM6/13 and SZ-21 to be distinct and that PM6/13 represents a useful tool to differentiate the characteristics of fibrinogen and fibronectin binding to the GPIIb-IIIa complex on activated platelets.

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