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001-es BibID:	BIBFORM033201
Első szerző:	Mendelboum Raviv, Shlomit (biológus)
Cím:	4-thio-deoxyuridylate modified thrombin aptamer and its inhibitory effect on fibrin clot formation, platelet aggregation and thrombus growrth on subendothelial matrix / S. Mendelboum Raviv, A. Horváth, J. Aradi, Z. Bagoly, F. Fazakas, Z. Batta, L. Muszbek, J. Hársfalvi
Dátum:	2008
ISSN:	1538-7933
Megjegyzések:	Background:?The consensus thrombin aptamer C15-mer is a single-stranded DNA of 15 nucleotides [d(GGTTGGTGTGGTTGG)] that was identified by the selection of thrombin-binding molecules from a large combinatorial library of oligonucleotides. It is capable of inhibiting thrombin at nanomolar concentrations through binding to a specific region within thrombin exosite 1. As has been shown in our earlier studies, the 4-thio-deoxyuridylate (s4dU)-containing oligonucleotides have high affinity for a number of proteins, due to the reduced hydrophilic character of the modified oligonucleotide. Methods:?Three different analogs of the original thrombin-inhibiting sequence, in which some of the thymidylate residues were replaced by 4-thio-deoxyuridylates, were synthesized. The inhibitory effect of modified aptamers was tested on thrombin-catalyzed fibrin clot formation and fibrinopeptide A release from fibrinogen, thrombin-induced platelet aggregation/secretion, and the formation of thrombus on coverslips coated with human collagen type III, thrombin-treated fibrinogen or subendothelial matrix of human microvascular endothelial cells. Results:?As compared with the C15-mer, the analog with the sequence GG(s4dU)TGG(s4dU)G(s4dU)GGT(s4dU)GG (UC15-mer) showed a 2-fold increased inhibition of thrombin-catalyzed fibrin clot formation, fibrinopeptide A release, platelet aggregation and secretion in human plasma and thrombus formation on thrombin-treated fibrinogen surfaces under flow conditions. Concerning the inhibition of thrombin-induced fibrin formation from purified fibrinogen and activation of washed platelets, UC15-mer was 3-fold and twelve-fold more effective than C15-mer, respectively.Conclusion:?The replacement of four thymidylate residues in C15-mer by 4-thio-deoxyuridylate resulted in a new thrombin aptamer with increased anticoagulant and antithrombotic properties.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban 4-thio-deoxyuridylate aptamer platelets thrombin thrombin exosite thrombus
Megjelenés:	Journal Of Thrombosis And Haemostasis. - 6 : 10 (2008), p. 1764-1771. -
További szerzők:	Horváth András (1976-) (vegyész) Aradi János (1942-) (biokémikus, vegyész) Bagoly Zsuzsa (1978-) (orvos) Fazakas Ferenc (1969-) (molekuláris biológus) Batta Zoltán Muszbek László (1942-) (haematológus, kutató orvos) Hársfalvi Jolán (1949-) (klinikai biokémikus)
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001-es BibID:	BIBFORM033194
035-os BibID:	PMID:22056526
Első szerző:	Mendelboum Raviv, Shlomit (biológus)
Cím:	Coating conditions matter to collagen matrix formation regarding von Willebrand factor and platelet binding / Shlomit Mendelboum Raviv, Katalin Szekeres-Csiki, Attila Jenei, Janos Nagy, Boris Shenkman, Naphtali Savion, Jolan Harsfalvi
Dátum:	2012
ISSN:	0049-3848
Megjegyzések:	IntroductionVon Willebrand factor (VWF) and platelet binding needs a uniform collagen matrix therefore we aimed to find an optimal condition for the preparation of human type-I and type-III collagen matrices.MethodThe effects of pH, salt and ligand concentration and binding time were tested when collagen matrices were prepared by adsorption. Surface-bound collagen and collagen-bound VWF measured by specific antibodies. Platelet adhesion was tested under flow conditions at a shear rate of 1800 s? 1 for 2 min. Matrices and platelets were visualized by atomic force and scanning electron microscope.ResultsThe extent of human collagens type-I and III binding to the surface was 10 and 4 times greater and binding was maximal under 8?16 hours, when coated from physiological buffer solution versus acid solution. Collagen fibrils were more developed and platelet adhesion was higher, with more organized and denser aggregates. VWF binding was parallel to the surface bound collagen in both collagen types.ConclusionCollagen coating of surfaces for VWF binding and platelet adhesion studies is very variable from acid solution. Our experiments provide evidences that neutralizing the acid and adding NaCl in physiological concentration, thereby facilitating formation of collagen fibril molecules in solution, results in efficient coating of human type-I and type III collagens, which then bind normal VWF equally well.
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban Collagen matrix Von Willebrand factor Platelet adhesion Thrombus formation egyetemen (Magyarországon) készült közlemény
Megjelenés:	Thrombosis Research. - 129 : 4 (2012), p. e29-e35. -
További szerzők:	Szekeres-Csiki Katalin (1979-) (orvos) Jenei Attila (1966-) (biofizikus) Nagy János (biofizikus) Shenkman, Boris Savion, Naphtali Hársfalvi Jolán (1949-) (klinikai biokémikus)
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