R. Marchi (1), H. Rojas (2), M. Meyer (3), O. Castillo (1), A. De Sáez Ruiz (4), J. W. Weisel (5)
(1) Centro de Medicina Experimental, Laboratorio Biología del Desarrollo de la Hemostasia, Instituto Venezolano de Investigaciones Científicas, Caracas, República Bolivariana de Venezuela; (2) Centro de Biofísica y Bioquímica, Laboratorio de Fisiología Celular, Instituto Venezolano de Investigaciones Científicas, Caracas, República Bolivariana de Venezuela; (3) University of Applied Sciences, Department of Medical Engineering and Biotechnology, Jena, Germany; (4) Banco Metropolitano de Sangre del Distrito Capital, Caracas, República Bolivariana de Venezuela; (5) Department of Cell & Developmental Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
A novel dysfibrinogenaemia with a replacement of Tyr by Asn at Bβ41 has been discovered (fibrinogen Caracas VIII). An asymptomatic 39-year-old male was diagnosed as having dysfibrinogenaemia due to a mildly prolonged thrombin time (+ 5.8 seconds); his fibrinogen concentration was in the low normal range, both by Clauss and gravimetric determination, 1.9 g/l and 2.1 g/l, respectively. The plasma polymerization process was slightly impaired, characterised by a mildly prolonged lag time and a slightly increased final turbidity. Permeation through the patients´ clots was dramatically increased, with the Darcy constant around four times greater than that of the control (22 ± 2 x10–9 cm2 compared to 6 ± 0.5 x10–9 cm2 in controls). The plasma fibrin structure of the patient, by scanning electron microscopy, featured a mesh composed of thick fibres (148 ± 50 nm vs. 120 ± 31 nm in controls, p<0.05) and larger pores than those of the control fibrin clot. The viscoelastic properties of the clot from the patient were also altered, as the storage modulus (G', 310 ± 30) was much lower than in the control (831 ± 111) (p ≤0.005). The interaction of the fibrin clot with a monolayer of human microvascular endothelial cells, by confocal laser microscopy, revealed that the patients´ fibrin network had less interaction with the cells. These results demonstrate the significance of the amino terminal end of the β chain of fibrin in the polymerisation process and its consequences on the clot organisation on the surface of endothelial cells.
scanning electron microscopy, mutation, confocal microscopy, abnormal fibrinogen, clots, permeation, viscoelastic properties
A. Wöhlke, C. Drögemüller, O. Distl
Tierärztliche Praxis Kleintiere 2007 35 5: 351-355
Akram Al-Hilali1, Karin Wulff2, Hikmat Abdel-Razeq3, Khalida Abu Saud1, Fateh Al-Gaili1, Falko H. Herrmann2
Thromb Haemost 2007 97 4: 542-545
A. Hafer, B. Mayer, H. Schunkert, J. Erdmann
Die Medizinische Welt 2007 58 1: 23-26
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