Összesen 3 találat.


001-es BibID:BIBFORM042213
035-os BibID:PMID:23216455
Első szerző:Reményi Gyula (belgyógyász, haematológus)
Cím:Comparison of coated-platelet levels in patients with essential thrombocythemia with and without hydroxyurea treatment / Gyula Reményi, Róbert Szász, Ildikó Beke Debreceni, Mariann Szarvas, Péter Batár, Béla Nagy Jr, János Kappelmayer, Miklós Udvardy
Megjegyzések:Essential thrombocythemia (ET) is an acquired myeloproliferative disorder with sustained increase of platelet count. This disease may be associated with thrombotic or bleeding complications due to the altered number and function of platelets. Coated-platelets produced by a simultaneous activation of collagen and thrombin represent a subpopulation of activated platelets with high prothombinase activity and the retention of several ?-granule-derived coagulation factors on their surface. There is a growing body of evidence for a relationship between variable levels of coated-platelets and different hemostatic alterations. However, no data are available on coated-platelet formation in the pathogenesis of ET in the presence or absence of treatment. The levels of coated-platelets in 43 ET patients (15 non-treated and 28 hydroxyurea-treated) without known thrombotic or hemorrhagic complications were analyzed using flow cytometry. These results were compared with data of 31 healthy individuals. In addition, platelet function was analyzed with PFA-100 analysis, and P-selectin (CD62) positivity was also measured by flow cytometry. Increased P-selectin expression was detected with prolonged PFA-100 closure times in the ET group; however, significantly lower levels of coated-platelets were found in non-treated ET patients compared to controls (23.1???8.8% vs. 37.6???12.7%, p?=?0.0008). This tendency was more evident in patients with JAK2-V617F mutation. Patients on hydroxyurea treatment had elevated coated-platelet levels (34.1???12.3%) close to the normal value. In conclusion, lower than normal levels of coated-platelets were generated in ET, which were significantly (p?=?0.0008) increased by hydroxyurea treatment. We suppose that abnormal coated-platelet level may also contribute to platelet dysfunction in ET.
Tárgyszavak:Orvostudományok Klinikai orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Essential thrombocythemia
platelet activation
flow cytometry
egyetemen (Magyarországon) készült közlemény
Megjelenés:Platelets. - 24 : 6 (2013), p. 486-492. -
További szerzők:Szász Róbert (1972-) (belgyógyász, haematológus) Bekéné Debreceni Ildikó (1970-) (biológus) Szarvas Mariann (1977-) Batár Péter (1969-) (belgyógyász, haematológus) Nagy Béla Jr. (1980-) (labordiagnosztikai szakorvos) Kappelmayer János (1960-) (laboratóriumi szakorvos) Udvardy Miklós (1947-) (belgyógyász, haematológus)
Internet cím:Szerző által megadott URL
Intézményi repozitóriumban (DEA) tárolt változat


001-es BibID:BIBFORM005096
Első szerző:Szarvas Mariann
Cím:Differential platelet deposition onto collagen in cone-and-plate and parallel plate flow chambers / Szarvas, M., Oparaugo, P., Udvardy, M. L., Tóth, J., Szántó, T., Daróczi, L., Vereb, G., Hársfalvi, J.
Megjegyzések:To routinely test the formation of thrombi and the effect of drugs modifying it, proper test systems are needed. Their design should rely on the laws of rheology and the physiology of laminar flow. To best model physiological or pathological shear conditions, parallel/linear and rotational type flow chambers are developed. We have compared the initial phase of platelet thrombus formation in a parallel plate flow chamber (PPC) and a cone-and-plate chamber (CPC) under von Willebrand dependent shear conditions. Blood was allowed to flow through human collagen type III surfaces at a shear rate of 1000 s(-1) for 150 s. Thrombus deposition was characterized by surface coverage, average area and height of thrombi. VWF distribution within thrombi was analyzed with confocal laser scanning microscopy. Reduced surface-specific platelet adhesion and aggregation (surface coverage and average thrombus size) were observed in CPC along with a significant increase in single platelet disappearance from the circulating blood. Our data suggest that the higher rate of platelet consumption in this device, as opposed to PPC, is limiting the adhesion to the surface. Consequently, surface-specific processes and aggregation in the flowing blood are both assessed using CPC, while comprehensive evaluation of surface-specific processes is best achieved with PPC. Therefore, the choice of chamber type as a diagnostic tool is purpose-dependent.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Collagen Type III
Image Processing
Linear Models
Platelet Adhesiveness
Platelet Aggregation
Research Support
von Willebrand Factor
Megjelenés:Platelets. - 17 : 3 (2006), p. 185-190. -
További szerzők:Oparaugo, Peter Udvardy Miklós László (1977-) (orvos, tudományos segédmunkatárs) Tóth Judit (1978-) (laboratóriumi szakorvos) Szántó Tímea Daróczi Lajos (1965-) (fizikus) Vereb György (1965-) (biofizikus, orvos) Hársfalvi Jolán (1949-) (klinikai biokémikus)
Internet cím:elektronikus változat
elektronikus változat


001-es BibID:BIBFORM009904
Első szerző:Tóth Judit (laboratóriumi szakorvos)
Cím:Increased platelet glycoprotein Ib number, enhanced platelet adhesion and severe cerebral ischaemia in a patient with polycythaemia vera / Toth J., Kappelmayer J., Udvardy M. L., Szanto T., Szarvas M., Rejto L., Soltesz P., Udvardy M., Harsfalvi J.
Megjegyzések:The present study describes severe multiplex cerebral ischaemic laesions in a male patient being diagnosed with polycythaemia vera (PV). In contrast to previous publications, unique platelet receptor pattern with normal platelet count was identified. Glycoprotein Ib receptor number on the surface of resting platelets was increased two-fold and almost three-fold in case of activated platelets compared to the controls. More over, in an in vitro study when whole blood was circulated both at venous and arterial shear conditions and shear rate was adjusted according to the blood viscosity, platelet aggregate/thrombus formation was characteristic on surfaces covered with purified von Willebrand factor while in case of controls the surface was covered with single platelets or platelet monolayer. Similar results with pathological findings have not been published in PV until now. Our result undersigns the necessity of antiplatelet therapy of PV patients, even at normal platelet count.
Tárgyszavak:Orvostudományok Klinikai orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:Platelets. - 20 : 4 (2009), p. 282-287. -
További szerzők:Kappelmayer János (1960-) (laboratóriumi szakorvos) Udvardy Miklós László (1977-) (orvos, tudományos segédmunkatárs) Szántó Tímea Szarvas Mariann (1977-) Rejtő László (1963-) (belgyógyász, haematológus) Soltész Pál (1961-) (belgyógyász, kardiológus) Udvardy Miklós (1947-) (belgyógyász, haematológus) Hársfalvi Jolán (1949-) (klinikai biokémikus)
Internet cím:Intézményi repozitóriumban (DEA) tárolt változat
elektronikus változat
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