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Cai H.,Service dhematologie biologique | Mullier F.,Namur Research Institute for Life science | Frotscher B.,Service dhematologie biologique | Briquel M.-E.,Service dhematologie biologique | And 5 more authors.
Seminars in Thrombosis and Hemostasis | Year: 2016

Dense granule disorder is one of the most common platelet abnormalities, resulting from dense granule deficiency or secretion defect. This study was aimed to evaluate the clinical usefulness of the flow cytometric combination of mepacrine uptake/release assay and CD63 expression detection in the management of patients with suspected dense granule disorder. Over a period of 5 years, patients with abnormal platelet aggregation and/or reduced adenosine triphosphate (ATP) secretion suggestive of dense granule disorder were consecutively enrolled. The flow cytometric assays were systematically performed to further investigate dense granule functionality. Among the 26 included patients, 18 cases showed impaired mepacrine uptake/release and reduced CD63 expression on activated platelets, consistent with δ-storage pool deficiency (SPD). Another seven patients showed decrease in mepacrine release and CD63 expression but mepacrine uptake was normal, indicating secretion defect rather than δ-SPD. Unfortunately, ATP secretion could not be measured in 7 out of the 26 patients due to insufficient sample and/or severe thrombocytopenia. This test combination provides a rapid and effective method to detect the heterogeneous abnormalities of platelet dense granule by distinguishing between storage and release defects. This combination is particularly advantageous for severely thrombocytopenic patients and pediatric patients in which only minimal sample is required. Copyright ©, Thieme Medical Publishers. All rights reserved. Source


Cai H.,Service dhematologie biologique | Mullier F.,Namur Research Institute for Life science | Frotscher B.,Service dhematologie biologique | Briquel M.-E.,Service dhematologie biologique | And 5 more authors.
Seminars in Thrombosis and Hemostasis | Year: 2016

Dense granule disorder is one of the most common platelet abnormalities, resulting from dense granule deficiency or secretion defect. This study was aimed to evaluate the clinical usefulness of the flow cytometric combination of mepacrine uptake/release assay and CD63 expression detection in the management of patients with suspected dense granule disorder. Over a period of 5 years, patients with abnormal platelet aggregation and/or reduced adenosine triphosphate (ATP) secretion suggestive of dense granule disorder were consecutively enrolled. The flow cytometric assays were systematically performed to further investigate dense granule functionality. Among the 26 included patients, 18 cases showed impaired mepacrine uptake/release and reduced CD63 expression on activated platelets, consistent with δ-storage pool deficiency (SPD). Another seven patients showed decrease in mepacrine release and CD63 expression but mepacrine uptake was normal, indicating secretion defect rather than δ-SPD. Unfortunately, ATP secretion could not be measured in 7 out of the 26 patients due to insufficient sample and/or severe thrombocytopenia. This test combination provides a rapid and effective method to detect the heterogeneous abnormalities of platelet dense granule by distinguishing between storage and release defects. This combination is particularly advantageous for severely thrombocytopenic patients and pediatric patients in which only minimal sample is required. Copyright © 2016 by Thieme Medical Publishers, Inc. Source


Mullier F.,Namur Research Institute for Life science | Mullier F.,University of Namur | Mullier F.,Namur Thrombosis and Hemostasis Center | Vanpee D.,CHU Dinant Godinne UCL Namur | And 9 more authors.
Blood Coagulation and Fibrinolysis | Year: 2014

There is still a considerable uncertainty concerning D-dimer cut-off values used in exclusion of venous thromboembolic (venous thromboembolism, VTE) disease, especially among the elderly patients. The objectives were to compare five different D-dimer reagents in the daily practice of an emergency department and to test retrospectively the performances of an age-adjusted cut-off. A total of 473 consecutive ambulatory outpatients suspected of VTE (confirmed VTE=21) were included in this study. Five commercially available tests were assessed: STA-Liatest D-Di (LI), AxSYMD-Dimer (AX), VIDAS D-Dimer (VI), INNOVANCE D-Dimer (IN), and HemosIL D-Dimer HS (HS). When using a cut-off value of 500ng/ml fibrinogen equivalent units (FEUs), D-dimer reagents differ in their abilities to avoid further testing. Indeed, LI allowed exclusion of VTE diagnosis in statistically more patients than VI, AX, and IN but not HS. The use of an age-adjusted cut-off is cost-effective without increasing significantly the number of false negative results. The interest of such strategy is more or less pronounced, depending on the type of D-dimer reagent. The application of an age-adjusted cut-off may be useful to reduce differences among D-dimer reagents to lower costly imaging studies. Prospective validation studies on large cohorts of patients are required to determine the safety of such strategy. © 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins. Source


Laloy J.,University of Namur | Laloy J.,Namur Research Institute for Life science | Mullier F.,University of Namur | Mullier F.,Namur Research Institute for Life science | And 17 more authors.
Nanotoxicology | Year: 2014

The study of the haemocompatibility of nanomaterials that could be in contact with blood (e.g. nanoparticle (NP)-based drug-delivery system) is of major importance. The primary objective of this study was to compare the ability of six platelet functional tests to assess the impact of NPs on platelet function. The secondary objective was to determine an accurate and reliable screening test to measure the potential impact of NPs on primary haemostasis whatever their physicochemical properties. Four types of carbon NPs (carbon black, fullerenes, single-walled carbon nanotubes and multi-walled carbon nanotubes) were investigated on six platelet function tests: light transmission aggregometry, whole-blood impedance aggregometry, platelet function analyser-100 (PFA-100®) and Cone-and-Plate(let) analyser (Impact-R®), transmission- and field emission gun scanning electron microscopy (FEG-SEM). We considered that Impact-R® supported by FEG-SEM is the reference method to investigate the potential impact of NPs on platelet function. © 2014 Informa UK, Ltd. Source


Bouchat V.,University of Namur | Bouchat V.,Namur Research Institute for Life science | Moreau N.,University of Namur | Moreau N.,Namur Research Institute for Life science | And 15 more authors.
Surface and Coatings Technology | Year: 2011

An approach using physical vapor deposition technology to produce nanoparticles (NPs) containing radioactive atoms and the methodology to transfer them in pure water is investigated. NPs are synthesized by magnetron sputtering at high pressure and radioactive atoms are loaded on magnetron cathodes prior to sputtering. The technique was tested for gold cathode loaded with 57/58Co and 195/196Au. Linked to biological vector molecules, the nanoparticles can be used to enhance diagnostic sensitivity in medical imaging or to treat cancer.Sizes and morphologies of the NPs were analyzed by electron microscopy, UV-Visible spectroscopy and atomic absorption spectroscopy. Results show well dispersed NPs with sizes varying between 5 and 10. nm. Activities of these NPs were measured with a CAPINTEC well counter and a High Purity Germanium detector system. Centrifugation analyses also demonstrate that the choice of the activated metal which can be alloyed with NPs plays an important role in the synthesis. This was confirmed by the Au-Co phase diagram that shows that cobalt cannot be included efficiently in the gold NPs conversely to gold. © 2011 Elsevier B.V. Source

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