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Vysokoškolská učebnice, která se zaměřuje na hemostázu a související klinické stavy a klinické hematologické testy. Určeno i pro odborníky v praxi.
- MeSH
- biomedicínský výzkum MeSH
- diferenciální diagnóza MeSH
- hematologické testy MeSH
- hematologie MeSH
- hemostáza MeSH
- koagulační faktory MeSH
- Konspekt
- Patologie. Klinická medicína
- Učební osnovy. Vyučovací předměty. Učebnice
- NLK Obory
- hematologie a transfuzní lékařství
- NLK Publikační typ
- kolektivní monografie
- učebnice vysokých škol
Heparin-induced thrombocytopenia (HIT) is a life-threatening complication of heparin therapy (both unfractionated heparin and low-molecular-weight heparin). In our study, we examined a group of 122 patients with suspected HIT. The samples of all patients were analyzed in the first step using an immunoassay (ID-PaGIA Heparin/PF4, Hemos1L-Acustar HIT IgG, ZYMUTEST HIA Monostrip IgG) to detect the presence of antibodies against heparin-PF4 complexes (platelet factor 4). When the immunoassay was positive, the sample was subsequently analyzed for HIT with a functional flow cytometry assay, the HITAlert kit, the purpose of which was to demonstrate the ability of the antibodies present to activate platelets. A diagnosis of HIT can be made only after a positive functional test result. In this article, we present an overview of our practical experience with the use of the new functional method of analysis, HIT, with flow cytometry. In this work, we compared the mutual sensitivity of two functional tests, SRA and the flow cytometry HITAlert kit, in patients perceived as being at risk for HIT. This work aims to delineate the principle, procedure, advantages, pitfalls, and possibilities of the application of the functional test HITAlert using flow cytometry.
- Publikační typ
- časopisecké články MeSH
The deficiency of natural anticoagulants-antithrombin (AT), protein C (PC), and protein S (PS)-is a highly predisposing factor for thrombosis, which is still underdiagnosed at the genetic level. We aimed to establish and evaluate an optimal diagnostic approach based on a high-throughput sequencing platform suitable for testing a small number of genes. A fast, flexible, and efficient method involving automated amplicon library preparation and target sequencing on the Ion Torrent platform was optimized. The cohort consisted of a group of 31 unrelated patients selected for sequencing due to repeatedly low levels of one of the anticoagulant proteins (11 AT-deficient, 13 PC-deficient, and 7 PS-deficient patients). The overall mutation detection rate was 67.7%, highest in PC deficiency (76.9%), and six variants were newly detected-SERPINC1 c.398A > T (p.Gln133Leu), PROC c.450C > A (p.Tyr150Ter), c.715G > C (p.Gly239Arg) and c.866C > G (p.Pro289Arg), and PROS1 c.1468delA (p.Ile490fs) and c.1931T > A (p.Ile644Asn). Our data are consistent with those of previous studies, which mostly used time-consuming Sanger sequencing for genotyping, and the indication criteria for molecular genetic testing were adapted to this process in the past. Our promising results allow for a wider application of the described methodology in clinical practice, which will enable a suitable expansion of the group of indicated patients to include individuals with severe clinical findings of thrombosis at a young age. Moreover, this approach is flexible and applicable to other oligogenic panels.
- Publikační typ
- časopisecké články MeSH
Von Willebrandov faktor (vWF) je multimerický proteín, ktorý plní dve kľúčové funkcie v hemostáze. Podieľa sa na interakcii medzi doštičkami a subendotelom v mieste cievneho poškodenia a interakcii medzi doštičkami navzájom. vWF tvorí komplex s faktorom VIII v pomere (1: 1), čím ho chráni pred proteolýzou aktivovaným proteínom C. vWF je proteín, ktorý je zostavený z identických podjednotiek do lineárnych reťazcov rôznej veľkosti označovaných ako multiméry. Tieto multiméry môžu mať hmotnosť > 20 miliónov daltonov a dĺžku > 2 mikrometre. Klinicky významné a najúčinnejšie pri interakcii s kolagénom a trombocytovými receptormi sú multiméry s vysokou molekulovou hmotnosťou (HMW). V článku uvádzame porovnanie dvoch dostupných metód analýzy multimérov von Willebrandovho faktora - klasickú manuálnu metódu a novú semiautomatickú metódu prístroja Hydrasys. Nová metóda využíva vopred pripravený 2% agarózový gél, výsledky sú dostupné do 6 h, metóda je štandardizovaná a reprodukovateľná. Avšak abnormality multimérov sa musia ďalej podrobnejšie skúmať pomocou klasickej - manuálnej metódy s rôznymi koncentráciami agarózových gélov.
Von Willebrand factor (vWF) is a multimeric protein that plays a principal role in two key functions in hemostasis. It participates in the interaction between the platelets and the subendothelium at the site of the vascular damage and if is also important in the interaction between the platelets. vWF is complexed with factor VIII (1: 1) to protect it from proteolysis by activated Protein C. vWF is a protein that is assembled from identical subunits into linear strings of varying size referred to as multimers. These multimers can be > 20 million daltons in mass and > 2 micrometers in length. Clinically significant and most effective in interacting with collagen and thrombocyte receptors are high molecular weight multimers. In our article we present comparing of two available methods of von Willebrand factor multimer analysis - the classical manual method and the new semi-automatic method of the Hydrasys instrument. The new method uses a prepared 2% agarose gel, the results are available within 6 h, the method is standardized and reproducible. However, abnormalities of multimers must be further investigated in more detail using the classical-manual method with different concentrations of agarose gels.
Congenital hypofibrinogenemia is a rare bleeding disorder characterized by a proportional decrease of functional and antigenic fibrinogen levels. Hypofibrinogenemia can be considered the phenotypic expression of heterozygous loss of function mutations occurring within one of the three fibrinogen genes (FGA, FGB, and FGG). Clinical manifestations are highly variable; most patients are usually asymptomatic, but may appear with mild to severe bleeding or thrombotic complications. We have sequenced all exons of the FGA, FGB, and FGG genes using the DNA isolated from the peripheral blood in two unrelated probands with mild hypofibrinogenemia. Coagulation screening, global hemostasis, and functional analysis tests were performed. Molecular modeling was used to predict the defect of synthesis and structural changes of the identified mutation. DNA sequencing revealed a novel heterozygous variant c.1421G>A in exon 8 of the FGB gene encoding a Bβ chain (p.Trp474Ter) in both patients. Clinical data from patients showed bleeding episodes. Protein modelling confirmed changes in the secondary structure of the molecule, with the loss of three β sheet arrangements. As expected by the low fibrinogen levels, turbidity analyses showed a reduced fibrin polymerisation and imaging difference in thickness fibrin fibers. We have to emphasize that our patients have a quantitative fibrinogen disorder; therefore, the reduced function is due to the reduced concentration of fibrinogen, since the Bβ chains carrying the mutation predicted to be retained inside the cell. The study of fibrinogen molecules using protein modelling may help us to understand causality and effect of novel genetic mutations.
- Publikační typ
- časopisecké články MeSH
- Klíčová slova
- AFSTYLA,
- MeSH
- dospělí MeSH
- faktor VIII * aplikace a dávkování farmakokinetika farmakologie MeSH
- hemofilie A farmakoterapie MeSH
- krvácení epidemiologie etiologie prevence a kontrola MeSH
- lidé MeSH
- mladiství MeSH
- rekombinantní proteiny aplikace a dávkování farmakologie škodlivé účinky MeSH
- sekundární prevence MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mladiství MeSH
- Publikační typ
- klinická studie MeSH