Temat: platelet reactivity

Skocz do pozycji: 1.

Tytuł:: Inhibition of collagen-induced platelet reactivity by DGEA peptide.
Autorzy:: Luzak, Boguslawa
Golanski, Jacek
Rozalski, Marcin
Boncler, Magdalena
Watala, Cezary
Tematy:: collagen
platelet receptor antagonists
collagen receptors
GPIaIIa
DGEA
platelet reactivity; Pokaż więcej
Wydawca:: Polskie Towarzystwo Biochemiczne
Powiązania:: https://bibliotekanauki.pl/articles/1043398.pdf Link otwiera się w nowym oknie
Opis:: Direct interactions between collagen, the most thrombogenic component of the extracellular matrix, and platelet surface membrane receptors mediate platelet adhesion and induce platelet activation and aggregation. In this process two glycoproteins are crucial: integrin α2β1, an adhesive receptor, and GPVI, which is especially responsible for signal transduction. Specific antagonists of the collagen receptors are useful tools for investigating the complexity of platelet-collagen interactions. In this work we assessed the usefulness of DGEA peptide (Asp-Gly-Glu-Ala), the shortest collagen type I-derived motif recognised by the collagen-binding integrin α2β1, as a potential antagonist of collagen receptors. We examined platelet function using several methods including platelet adhesion under static conditions, platelet function analyser PFA-100TM, whole blood electric impedance aggregometry (WBEA) and flow cytometry. We found that DGEA significantly inhibited adhesion, aggregation and release reaction of collagen activated blood platelets. The inhibitory effect of DGEA on static platelet adhesion reached sub-maximal values at millimolar inhibitor concentrations, whereas the specific blocker of α2β1 - monoclonal antibodies Gi9, when used at saturating concentrations, had only a moderate inhibitory effect on platelet adhesion. Considering that 25-30% of total collagen binding to α2β1 is specific, we conclude that DGEA is a strong antagonist interfering with a variety of collagen-platelet interactions, and it can be recognised not only by the primary platelet adhesion receptor α2β1 but also by other collagen receptors.
Dostawca treści:: Biblioteka Nauki

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Tytuł:: Association of ADP-induced whole-blood platelet aggregation with serum low-density lipoprotein cholesterol in patients with coronary artery disease when receiving maintenance ticagrelor-based dual antiplatelet therapy
Autorzy:: Chyrchel, Bernadeta
Kruszelnicka-Kwiatkowska, Olga
Surdacki, Andrzej
Wieczorek-Surdacka, Ewa
Opis:: The degree of platelet inhibition in patients undergoing dual antiplatelet therapy (DAPT) affects cardiovascular outcomes after acute coronary syndromes (ACS) and/or percutaneous coronary intervention. Our aim was to search for correlates of residual ex vivo platelet reactivity and circulating soluble P-selectin (sP-selectin), an index of in vivo platelet activation, in patients being treated by DAPT with ticagrelor. Adenosine diphosphate (ADP)-induced platelet aggregability (by multiple electrode aggregometry) and plasma sP-selectin were estimated in 62 stable post-ACS subjects (46 men and 16 women; mean age: 64 ± 10 years; 30 with type 2 diabetes (T2DM)) undergoing maintenance DAPT with ticagrelor and aspirin. These patients did not exhibit heart failure or other relevant coexistent diseases except for properly controlled T2DM, mild renal insufficiency, and hypertension. We also assessed this in 64 subjects on clopidogrel-based DAPT matched for age, sex, and T2DM status. ADP-induced platelet aggregation was below the optimal levels (190–460 arbitrary units (AU) * min) in most patients receiving ticagrelor-based DAPT, especially in those with below-median (<1.9 mmol/L) serum concentrations of low-density lipoprotein cholesterol (LDL-c) (128 ± 61 vs. 167 ± 73 AU * min for below-median and above-median LDL-c, respectively, p = 0.025). In contrast, platelet reactivity did not differ by LDL-c on clopidogrel-based DAPT (246 ± 101 vs. 268 ± 108 AU * min for below-median and above-median LDL-c, respectively, p > 0.4). Plasma sP-selectin was found to be unrelated to serum LDL-c when receiving DAPT with ticagrelor (p > 0.4) or clopidogrel (p > 0.8). In conclusion, our preliminary observational study suggests the association of lower residual ex vivo platelet aggregability with better LDL-c control in patients undergoing ticagrelor-based maintenance DAPT, which does not appear to be reflected by plasma sP-selectin. Whether the serum LDL-c level should be considered among the factors affecting the degree of platelet inhibition for those treated with ticagrelor-based DAPT needs to be investigated in larger studies.
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego

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Tytuł:: Altered platelet reactivity, coagulation, endothelial and inflammatory markers early after smoking cessation verified with cotinine plasma concentration
Autorzy:: Budaj, Andrzej
Undas, Anetta
Ramotowski, Bogumił
Opis:: Background/Introduction: Cigarette smoking is a potent modifiable risk factor for coronary artery disease (CAD). However, little is known about alterations to prothrombotic state and platelet reactivity early after smoking cessation following percutaneous coronary interventions (PCI). Purpose: We investigated alterations to platelet reactivity, coagulation and markers of platelet, endothelial, inflammatory and coagulation activation in clopidogrel-treated patients with CAD after PCI before and after smoking cessation. Methods: Smoking patients aged 18 years or older at least 30 days after PCI were recruited and encouraged to quit the habit. At baseline and at 30 days, we measured platelet reactivity with VerifyNow system, thrombomodulin, P-selectin, platelet factor 4 (CXCL4/PF4), citrullinated histone H3 (H3cit) and cotinine level. Results: Among 117 patients, 84 patients (72%) at a median age of 60.5 years (40 [interquartile range 30–47] pack-years) completed a 30-day follow-up. At day 30, 30 (35.7%) patients stopped smoking with cotinine level < 50 ng/ml. Baseline characteristics were similar in both groups. In smoking quitters a change in platelet reactivity was larger (Δ platelet reactivity units (PRU) 19 [2, 43] vs. -6 [-32, 37], p = 0.018), along with a change in P-selectin concentration (-11.82 [-23.62, 1.34] vs. 7.19 [-14.24, 17.19] ng/ml, p = 0.005). Positive correlations was noticed between cotinine and both P-selectin ( r = 0.23, p = 0.045) and CXCL4 (r = 0.27, p = 0.02). Conclusion: After smoking cessation in CAD patients following PCI an increase in platelet reactivity and a decrease in P-selectin levels were observed. The risk of thrombotic complications post PCI might be paradoxically enhanced among patients who stopped smoking.
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego

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Tytuł:: Aspirin resistance in adult patients after Fontan surgery
Autorzy:: Podolec, Jakub
Tomkiewicz-Pająk, Lidia
Podolec, Piotr
Sitek, Barbara
Rubiś, Paweł
Wójcik, Tomasz
Komar, Monika
Olszowska, Maria
Musiałek, Piotr
Pająk, Jacek
Chłopicki, Stefan
Opis:: Background: Thrombotic complications are common in adult patients who have had a Fontan operation early in life for treatment of congenital heart disease. Objective: To characterize platelet function and responsiveness to aspirin in relation to thrombogenesis, systemic inflammation, and markers of endothelial function in adults with Fontan circulation (FC). Methods: Thirty-four FC patients (age 18–40 years; 62% taking aspirin chronically and 38% not taking aspirin) and 32 age- and sex-matched healthy controls were studied. Platelet function was evaluated by measurement of basal concentrations of thromboxane B2 (TXB2) and sCD40L and ex-vivo generation of TXB2 and sCD40L. Plasma concentrations of thrombin–antithrombin, endothelin-1, vWF, IL-6, IL-8, MCP-1, MIP-1β, TNFα, sVCAM-1, and syndecan-1 also were measured. Results: Platelet numbers were significantly lower in FC patients than in controls, but the patients had significantly higher platelet activity, as evidenced by higher TXB2 and sCD40L concentrations and higher ex vivo generation of TXB2. Chronic aspirin treatment had no effect on plasma concentrations of TXB2 and sCD40L in FC, but in 52% of aspirin-treated FC subjects, TXB2 concentrations remained elevated at 60 min of TXB2 generation, indicating aspirin resistance. In addition, FC patients had increased levels of thrombin–antithrombin, endothelin-1, vWF, IL-8, MCP-1, MIP-1β, TNFα, sVCAM-1, and syndecan-1 but not of IL-6. Conclusion: Adults with FC had lower platelet numbers but increased platelet activity, increased thrombogenesis, systemic inflammation, and endothelial dysfunction. A significant proportion of aspirin-treated FC adults had aspirin resistance, which may be at least in part responsible for their increased incidence of thrombotic complications.
Dostawca treści:: Repozytorium Uniwersytetu Jagiellońskiego

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