Platelet activation. Medical search. Frequent questions

Induced platelet aggregation Blood Platelets Flow cytometry Thrombin Fibrinogen Secretion Adhesion Vitro Thrombus Thrombosis Receptors Involved in platelet aggregation and activation Adenosine Role for platelet Stimulation Reactivity Molecular mechanisms of platelet activation Pathways Receptor Anti-platelet Disorders of Platelet Function Endotheliopathy and Platelet Dysfunction Mechanisms Vascular Significantly Stage of platelet activation Amplification of platelet activation Assess platelet activation Proteins Activate platelets Mediates platelet Aggregates Interactions with platelets Phosphorylation Endothelial cells Inhibition Granules Integrin PDGF Changes in platelet Regulation of platelet Aggregate Extent of platelet Defects Protein Glycoprotein Inhibitory effect Markers Inhibitors Inhibit Vivo Cytoskeletal reorganization Aggregometry Membrane Dysfunction Formation Aggregation assay IIIa Inflammation Antibody Results

CD69 stimulation by anti-Leu-23 monoclonal antibodies induced platelet aggregation in a dose-dependent fashion. (nih.gov)
The capacity for bacteria-induced platelet aggregation was also shown to be transferable between donors through serum. (lu.se)
In our previous study, several compounds extracted from this herb, including luteolin‑4'‑O‑β‑D‑glucopyranoside (LGP), were revealed to exert inhibitory effects on adenosine diphosphate (ADP)‑induced platelet aggregation. (spandidos-publications.com)
However, while prednisolone (1-10 μM) reduced adenosine diphosphate (ADP, 4 μM) and thromboxane A 2 receptor agonist U46619 induced platelet aggregation (up to 75%), dexamethasone had no effect. (ashpublications.org)
mTOR inhibitors dramatically reduced collagen-induced platelet aggregation and promoted the destabilization of platelet aggregates formed under shear flow conditions. (researchtoactionforum.org)
The collagen-induced platelet aggregation of platelet-rich plasma samples from 14 healthy rabbits was measured turbidometrically using a platelet aggregometer, before and 1 hour after intravenous injection of alum. (who.int)
Collagen-induced platelet aggregation was significantly reduced after alum injection. (who.int)

However, no ex vivo studies suggest that circulating androgen levels influence the activation and reactivity of blood platelets - one of the main components of the haemostasis system directly involved in atherosclerosis. (aging-us.com)
Our findings indicate that testosterone and dihydrotestosterone are significant haemostatic steroids with inhibitory action on blood platelets in older people. (aging-us.com)
PRP samples and peripheral blood platelets were then manually counted using a Neubauer chamber. (bvsalud.org)

Aggregation was studied using light-transmission aggregometry and platelet activation using flow cytometry detecting. (lu.se)
Aggregation was studied using light-transmission aggregometry and platelet activation using flow cytometry detecting surface upregulation of CD62P. (lu.se)
Procedure -Flow cytometry was used to assess platelet activation as indicated by detection of binding of fluorescent-labeled annexin V, anti-human fibrinogen antibody, and anti-thrombospondin antibody to unactivated and ADP-, collagen-, platelet activating factor (PAF)-, and A23187-activated equine platelets. (avma.org)
Expression of platelet CD62P (P-selectin), platelet aggregation, Ca2+ fluxes and phosphorylation of Akt1 were measured using flow cytometry, spectrophotometry, fluorescence spectrometry, and by ELISA procedures, respectively. (up.ac.za)
the aim was to identify any potential relationships between sex steroid levels and the markers of platelet activation (surface membrane expression of GPII/IIIa complex and P-selectin) and platelet reactivity in response to arachidonate, collagen or ADP, monitored with whole blood aggregometry and flow cytometry. (aging-us.com)
Apoptosis was determined by flow cytometry analysis through FITC-annexin V binding to platelet membrane PS exposed under basal conditions and after stimulation with a PAR-1 receptor agonist (TRAP, SFLLRN, thrombin receptor-activating peptide 6). (ashpublications.org)
Platelet activation was determined through FITC-fibrinogen, FITC-PAC-1 (a mAb that recognizes activated conformation of fibrinogen receptor) and FITC-P-selectin mAb binding to quiescent and 100 mM TRAP activated platelets by flow cytometry. (ashpublications.org)
Methods: Short-and long-term effects of glycoprotein VI (GPVI) and G protein-coupled receptor (GPCR) stimulation on platelet activation and aggregation potential were compared via flow cytometry and plate-based aggregation. (reading.ac.uk)
Transcripts/peptides of Notch1 and Delta-like ligand (DLL)-4 were detected in platelets isolated from human blood by RT-qPCR, Western analysis and flow cytometry. (elifesciences.org)
Platelet aggregation, granule secretion and platelet-leukocyte interaction were analyzed by lumi-aggregometry and flow cytometry. (elifesciences.org)
Platelet count and activation were assessed by flow cytometry, and thrombus formation was analyzed intravitally or in tissue sections using different imaging modalities. (isth.org)
Platelets were analyzed by flow cytometry for relative size, shape, aggregation, fibrinogen binding, P-selectin, and lysosomal-associated membrane protein-1 (LAMP-1) expression. (cdc.gov)

Proteogenomics was applied here to investigate this phenomeon in platelets activated in vitro with Collagen or Thrombin Receptor Activating Peptide. (nature.com)
The physiological agonist thrombin and the pathophysiological relevant agonist lysophosphatidic acid (LPA), which is the main platelet-activating lipid in atherosclerotic plaque, were used as platelet stimuli to address these questions. (uni-muenchen.de)
Our study shows that LIMK-1 activation was mainly Rho-kinase dependent in LPA- and thrombin-stimulated platelets. (uni-muenchen.de)
Surprisingly, the activation of LIMK-1 failed to increase cofilin phosphorylation during shape change induced by LPA as well as by thrombin. (uni-muenchen.de)
After stimulation with LPA and thrombin under conditions, where platelet aggregation could not occur, the kinetics of cofilin de- and rephosphorylation were unperturbed indicating their independence of integrin IIbβ3 engagement. (uni-muenchen.de)
Furthermore, the results clearly showed that cofilin dephosphorylation is also independent and upstream of secretion, since the onset of cofilin dephosphorylation was as rapid as secretion in thrombin-stimulated platelets and also occurred in the absence of dense granule secretion in LPA (10 µM)-stimulated platelets. (uni-muenchen.de)
Since the kinetics of cofilin phospho-cycle was similar during secretion and platelet aggregation in LPA- and thrombin-stimulated cells, I propose a general two-step regulatory process for cofilin phospho-cycle underlying primarily secretion, and subsequently platelet aggregation: dephosphorylation by a cofilin phosphatase and then rephosphorylation by the Rho-kinase/LIMK-1 pathway. (uni-muenchen.de)
Upon vascular injury, platelets are exposed to the subendothelium, and several agonists, including adenosine diphosphate (ADP) and thrombin, are generated at the injury site, which can stimulate platelet adhesion, activation and aggregation. (spandidos-publications.com)
Platelet-rich plasma (PRP) or isolated cells prepared from the blood of healthy, adult humans were treated with bedaquiline (0.625-10 μg/ml), followed by activation with adenosine 5'-diphosphate (ADP), thrombin or the thromboxane A2 receptor agonist (U46619). (up.ac.za)
Exposure to bedaquiline caused dose-related inhibition of ADP-activated, but not thrombin- or U46619-activated, expression of CD62P by platelets, achieving statistical significance at a threshold concentration of 5 μg/ml and was paralleled by inhibition of aggregation and Ca2+ mobilization. (up.ac.za)
Interestingly, the addition of exogenous dRP to human platelets significantly increased platelet aggregation and integrin αIIbβ3 activation in response to thrombin. (bath.ac.uk)
In parallel, genetically modified platelets with double genetic deletion of thymidine phosphorylase and uridine phosphorylase were characterised by reduced release of dRP, impaired aggregation and decreased integrin αIIbβ3 activation in response to thrombin. (bath.ac.uk)
This initial interaction (platelet adhesion) sets the stage for other adhesive reactions that allow the platelets to interact with other agonists in the vicinity of vessel injury, such as adenosine 5'-diphosphate (ADP), subendothelial collagen, and thrombin. (medscape.com)
Furthermore, we used this assay to develop a PAR 1 receptor-activating probe [Ala-parafluoroPhe-Arg-Cha-Cit-Tyr-NH 2 (Cit-NH 2 )], which displays a high degree of specificity for PAR 1 over PAR 2 , and we used the assay to quantitate the ability of trypsin to disarm the activation of PAR 1 by thrombin. (aspetjournals.org)
Platelets were activated with ADP, thrombin, or the thrombin receptor agonist peptide SFLLRN (TRAP 1-6 ). (nature.com)
Results: After 30 minutes of stimulation with thrombin receptor activator peptide 6 (TRAP6) or adenosine diphosphate (ADP), platelets secondarily decreased in PAC-1 binding and were less able to aggregate. (reading.ac.uk)
The reversibility of platelets after thrombin timulation was concentration dependent. (reading.ac.uk)
In contrast, cross-linked collagen-related peptide (CRP-XL) or high thrombin stimulation evoked persistent effects in αIIbβ3 activation and platelet aggregation. (reading.ac.uk)
However, after 60 minutes of CRP-XL or high thrombin stimulation, when αIIbβ3 activation slightly decreased, restimulation with ADP or CRP-XL, respectively, increased integrin activation again. (reading.ac.uk)
Strikingly, prevention of DLL-4-Notch1 interaction by a blocking antibody abolished platelet aggregation and extracellular vesicle shedding induced by thrombin. (elifesciences.org)
Stimulation of platelets by thrombin resulted in up-regulation of LAMP-1 expression in CAPs-exposed animals and an increased microparticle population relative to control animals. (cdc.gov)
Platelet aggregation studies test the clumping response of platelets to various platelet activators (eg, ADP, collagen, arachidonic acid, thrombin, epinephrine, ristocetin) as continuously recorded by a light transmission aggregometer. (medscape.com)

Fibrinogen mediated activation of platelet aggregation. (bmj.com)
Anti-human fibrinogen antibody bound to ADP-, PAF-, and A23817- activated platelets, but binding was not dependent on platelet secretion. (avma.org)
The extent of binding of anti-fibrinogen antibody was less in equine platelets, compared with that for human platelets, despite maximal stimulation. (avma.org)
Conclusions and Clinical Relevance -Activation of equine platelets can be detected by use of fluorescent- labeled annexin V and anti-human fibrinogen antibody but not by use of anti-human thrombospondin antibody. (avma.org)
In vitro platelet adhesion onto fibrinogen and collagen under physiological flow conditions was potentiated by treatment of human platelets with exogenous dRP and impaired in transgenic platelets with reduced dRP release. (bath.ac.uk)
On resting platelets, GP IIb/IIIa is unable to bind fibrinogen or vWf. (medscape.com)
The alpha granules contain hemostatic proteins such as fibrinogen, vWf, and growth factors (eg, platelet-derived growth factor and transforming growth factors). (medscape.com)
Pharmacologic inhibitors of mTOR and S6K1 blocked Rac1 activation and prevented platelet spreading on fibrinogen but had no effect on Src or FAK kinase activation. (researchtoactionforum.org)
Flow cytometric analysis of unstimulated platelets from CAPs-exposed mice indicated size and shape changes, and platelets from CAPs-exposed animals had a 54% increase in fibrinogen binding indicative of platelet priming. (cdc.gov)
Platelet activation promotes platelet aggregation and fibrinogen binding and requires the platelet glycoprotein IIb/IIIa complex. (msdmanuals.com)
Additionally, ADP (and thromboxane A2) then promotes changes in the platelet glycoprotein IIb/IIIa complex, which in turn increases fibrinogen binding, thereby allowing platelets to aggregate. (msdmanuals.com)

The activation of Rho-kinase was found to be upstream to secretion and integrin IIbβ3 activation. (uni-muenchen.de)
The rapid activation of Rho-kinase during secretion leads to a further increase in F-actin content as compared to shape change. (uni-muenchen.de)
It was also found that LGP exhibited marked inhibitory effects on the activation of αIIbβ3 integrin, the secretion of serotonin from granules, and the synthesis of thromboxane A2. (spandidos-publications.com)
Determination of 14C-serotonin uptake and release was used to assess the extent of platelet secretion. (avma.org)
Annexin V bound to platelets activated with PAF or A23187 when platelets had undergone secretion. (avma.org)
Interestingly, reactivation of reversed platelets again resulted in shape change and if not fully degranulated, additional secretion. (reading.ac.uk)
Norpurpureine inhibits platelet secretion. (biomedcentral.com)
With some aggregometers, the secretion of platelet granules, another indicator of platelet function, may also be evaluated simultaneously by measuring the release of ATP by the aggregating platelets. (medscape.com)
Platelet secretion defects can provide greater diagnostic sensitivity than platelet aggregation testing alone. (medscape.com)

The body's reaction to vessel wall injury is rapid adhesion of platelets to the subendothelium. (medscape.com)
Platelet receptors and released molecules play a critical role during the initiation and the progression of atherosclerosis by mediating leukocytes recruitment and adhesion to the vascular wall. (ox.ac.uk)
Dysfunctional endothelium itself releases inflammatory molecules leading toward platelets activation and adhesion to the vascular wall. (ox.ac.uk)
On the contrary, prior platelet triggering with CRP-XL was accompanied by prolonged platelet activity, leading to a decreased secondary platelet adhesion under flow. (reading.ac.uk)
Platelet adhesion is one of the most pivotal events of blood clotting for artificial surfaces. (elsevierpure.com)
In this study, we attempted to observe the internal structures and adhesion interfaces of human platelets attached to artificial surfaces by transmission electron microscopy (TEM) during the platelet activation process. (elsevierpure.com)
In addition, along with the process of platelet activation, the gap between the platelet membrane and the material surface at the interface disappeared and a-platelet/material adhesion became much tighter. (elsevierpure.com)
We also observed host-dependent differences for interaction of platelets with C. albicans , showing enhanced platelet aggregation, adhesion and activation in murine blood. (frontiersin.org)
Platelet adhesion (ie, of platelets to exposed vascular subendothelium) requires von Willebrand factor (VWF) and the platelet glycoprotein Ib/IX complex. (msdmanuals.com)
It impairs platelet adhesion via a defect in the glycoprotein Ib/IX complex that binds endothelial VWF. (msdmanuals.com)
is due to a deficiency or defect in the von Willebrand factor (VWF) that is needed to permit platelet adhesion. (msdmanuals.com)

Accordingly, we have investigated augmentation of the reactivity of human platelets in vitro as a potential mechanism of bedaquiline-mediated cardiotoxicity. (up.ac.za)
These observations were confirmed in an in vitro model: testosterone and dihydrotestosterone significantly inhibited platelet aggregation triggered by arachidonate or collagen. (aging-us.com)
Platelet aggregometry is a standard clinical technique that measures the in vitro aggregability of platelets in response to agonists by using the amount of light transmitted through platelet-rich plasma (PRP) ( Holmsen, 1987 ). (nature.com)
The bivalent anti-CLEC-2 antibody INU1 triggers platelet activation in vitro, while this is not the case for the monovalent INU1-fab fragment. (isth.org)

Platelet activation triggers thrombus formation in physiological and pathological conditions, such as acute coronary syndromes. (nature.com)
The activation of platelets is a central step during the physiological process of hemostasis and its understanding may lead us to control the pathophysiological process of intra-arterial thrombus formation and vascular occlusion, which can cause acute coronary syndrome and myocardial infarction. (uni-muenchen.de)
Platelet activation and subsequent accumulation at sites of vascular injury are central to thrombus formation, which is considered to be a trigger of several cardiovascular diseases. (spandidos-publications.com)
Adherent, activated platelets recruit additional platelets to the growing thrombus ( 5 , 6 ). (spandidos-publications.com)
Now just as way of background, we all know that platelet activation is essential to thrombus formation during atherosclerosis. (cardiologytalk.com)
So anything that promotes, platelet activation such as inflammatory stimuli like angiotensin II and cytokines like IL-6, they'll trigger that condition leading to thrombus formation and ischemic events. (cardiologytalk.com)
Objectives: To investigate the extent to which previously activated platelets can be reactivated and whether in-and reactivation applies to different aspects of platelet activation and thrombus formation. (reading.ac.uk)
Using fluorescence and electron microscopy, we assessed platelet morphology and content, as well as thrombus formation. (reading.ac.uk)
Moreover, platelets that were previously activated with TRAP6 or ADP regained their potential to contribute to thrombus formation under flow. (reading.ac.uk)
Reversed, previously activated platelets can contribute to thrombus formation. (reading.ac.uk)
Platelet thrombus on immobilized collagen was quantified using microfluidics platform. (elifesciences.org)
describes a novel signaling pathway involving Notch1 and its ligand, Δ-like ligand-4 (DLL4) in driving platelet activation and thrombus formation. (elifesciences.org)
Platelet activation and thrombus formation are under the control of signaling systems that integrate cellular homeostasis with cytoskeletal dynamics. (researchtoactionforum.org)
Background Accelerated thrombus formation induced by exposure to combustion-derived air pollution has been linked to alterations in endogenous fibrinolysis and platelet activation in response to pulmonary and systemic inflammation. (anma.it)
Conclusion DEP accelerates arterial thrombus formation through increased platelet activation. (anma.it)

Platelets are anucleate cytoplasmic fragments, deriving from precursor megakaryocytes, which play key roles in processes such as thrombosis, hemostasis, inflammation, wound healing and angiogenesis. (nature.com)
Platelets are small, a nucleate blood cells, the major role of which is in hemostasis and thrombosis owing to their capacity to adhere to damaged blood vessels and to accumulate at sites of injury ( 1 ). (spandidos-publications.com)
It has been demonstrated clinically that the use of antiplatelet agents to prevent and/or reverse platelet aggregation is a successful strategy for the prevention of thrombosis ( 7 , 8 ). (spandidos-publications.com)
GP IIb/IIIa receptor activation plays an important role in thrombosis. (aging-us.com)
In thrombosis, platelet activation serves as the initiation factor. (aging-us.com)
Under physiological circumstances, the resistance of the endothelial cell lining to interactions with platelets and coagulation factors prevents thrombosis. (medscape.com)
Further to the established role of platelets in thrombosis and hemostasis, increasing evidence suggests that they also play a crucial role in atherogenesis. (ox.ac.uk)
Platelets are no longer considered simply as cells participating in thrombosis. (ox.ac.uk)
Eicosapentaenoic Acid: Modulated Platelet Activation and Thrombosis Proteins in Vascular Endothelial Cells During Inf. (cardiologytalk.com)
The title of my presentation that was given there is Eicosapentaenoic Acid or EPA modulates the expression or proteins linked to platelet activation and thrombosis in vascular endothelial cells during inflammation. (cardiologytalk.com)
Inhibition of Notch signaling, too, restrained agonist-induced platelet activation, and significantly impaired arterial thrombosis in mice. (elifesciences.org)
In addition, the efficacy of the stent configurations for promoting aneurysm thrombosis was assessed by simulations of residence time and platelet activation. (springer.com)
Recent studies suggested a role for platelet ITAM signaling in venous thrombosis. (isth.org)
CLEC-2 dependent platelet activation results in cerebral venous thrombosis. (isth.org)

The mechanism of early activation of GP IIb/IIIa receptors in diabetic conditions remains unknown. (aging-us.com)
In conclusion, EMP-PDI promotes early platelet activation through glycoprotein (GP) IIb/IIIa receptors present on platelet surface in the diabetic state. (aging-us.com)
However, the ultimate common pathway of platelet aggregation is the activation of glycoprotein (GP) IIb/IIIa receptors present on platelet surface [ 7 - 9 ]. (aging-us.com)
The identification of the key molecules that accurately regulate the activation of these receptors may provide a novel approach for antiplatelet therapy. (aging-us.com)
Platelet activation following inflammatory stimulus leads to the expression of surface receptors such as GPIb/IX/V, P-selectin, CD40, and to the release of several pro-inflammatory agents. (ox.ac.uk)
We developed a calcium signaling-based assay, using cultured human embryonic kidney cells (HEK), that evaluates simultaneously, the activation/desensitization or blockade of the proteinase-activated receptors, PAR 1 and PAR 2 . (aspetjournals.org)
The signaling events during the GABA-mediated inhibition of platelet activation and whether platelets express GABA-like binding receptors are also determined. (tmu.edu.tw)

Platelets and serum were treated with different inhibitors to determine mechanisms involved in platelet aggregation and activation. (lu.se)
Genes involved in platelet aggregation and activation are downregulate" by Francesca M. McGrath, Abbie Francis et al. (edu.au)
Conclusion: Downregulation of genes involved in platelet aggregation and activation is a unique feature of the early anaphylactic reaction not previously reported and may be associated with reaction severity. (edu.au)

This effect was associated with Ca2+ influx and platelet degranulation, as revealed by adenosine triphosphate release. (nih.gov)
Other agonists for platelet formation and aggregation such as adenosine diphosphate (ADP) or pathways mediated by convulxin also do not seem inhibited by the toxin in most organisms. (wikipedia.org)
The primary endpoint was assessment of platelet aggregation after stimulation with adenosine diphosphate 20 μM at 12-month follow-up. (revespcardiol.org)
Activation involves release of adenosine diphosphate (ADP) from platelet storage granules and conversion of arachidonic acid to thromboxane A2 via a cyclooxygenase-mediated reaction. (msdmanuals.com)

These observations suggest an alternative role for platelet shape change of single platelets. (nature.com)
These findings demonstrate a systemic proinflammatory and procoagulant response to inhalation of environmentally derived fine and ultrafine PM and suggests a role for platelet activation in the cardiovascular and respiratory effects of particulate air pollution. (cdc.gov)

In addition, CD69 stimulation in platelets induced production of thromboxane B2 and PGE2, suggesting activation of arachidonic acid metabolism by cycloxygenase. (nih.gov)
One of the important aspects of platelet activation is to understand the dynamic regulation and rearrangement of the cytoskeleton after stimulation. (uni-muenchen.de)
These results clearly indicate that human platelets contain high levels of GABA, which, upon stimulation, it is readily released from platelets and further contributes to be circulating GABA, and it may be taken as an endogenous antithrombotic agent. (tmu.edu.tw)

Karolczak K , Konieczna L , Kostka T , Witas PJ , Soltysik B , Baczek T , Watala C , . Testosterone and dihydrotestosterone reduce platelet activation and reactivity in older men and women. (aging-us.com)
The results of the ex vivo part of the study indicate that the concentrations of testosterone and its reduced form, dihydrotestosterone are significantly negatively associated with platelet activation and reactivity. (aging-us.com)
We aimed to investigate the biological impact of a tailored clopidogrel loading dose (LD) according to platelet reactivity monitoring in carriers of the cytochrome (CYP) 2C19*2 loss-of-function polymorphism undergoing percutaneous coronary intervention for an acute coronary syndromes. (nih.gov)
Platelet reactivity was measured using the vasodilator-stimulated phosphoprotein (VASP) index, and a cutoff value of ≥ 50% was used to define high on-treatment platelet reactivity (HTPR). (nih.gov)
Increased and tailored clopidogrel loading dose according to platelet reactivity monitoring overcome HTPR in carriers of the loss-of-function CYP2C19*2 polymorphism. (nih.gov)
Intensive glucose control with insulin in patients with an acute coronary syndrome reduces platelet reactivity during hospitalization, compared to conventional control. (revespcardiol.org)
However, the effect of strict, long-term glucose control on platelet reactivity in these patients remains uncertain. (revespcardiol.org)
180 mg/dL), on platelet reactivity after hospital discharge in patients with an acute coronary syndrome and hyperglycemia. (revespcardiol.org)

Therefore, understanding the molecular mechanisms of platelet activation and identifying novel techniques for platelet inhibition remain critically important. (spandidos-publications.com)
Together these results reveal novel roles for S6K1 and mTOR in the regulation of 10058-F4 Rac1 activity and provide insights into the relationship between the pharmacology of the mTOR system and the molecular mechanisms of platelet activation. (researchtoactionforum.org)

Thus, modulation of platelet aggregation and coagulation pathways represents the main therapeutical strategy pursued in the management of thrombotic disorders 4 . (nature.com)
The Streptococcus bovis/Streptococcus equinus complex (SBSEC) contains known IE-pathogens, but there is limited research on the different subspecies ability to interact with platelets and what signaling pathways are involved. (lu.se)
Experiments directly assessing the activation of the small G protein Rap1b and protein kinase C suggested that dRP increases the basal levels of activity of these two pivotal platelet-activating pathways in a redox-dependent manner. (bath.ac.uk)
Platelet activation pathways. (medscape.com)
The metalloproteinase disintegrin-like domain has shown an ability to degrade sub-endothelial matrix proteins such as type IV collagen, and fibronectin which is partially responsible for the hemorrhage caused by the toxin The cysteine-rich domain binds to the alpha-2/beta-1 integrin and causes inhibition of the platelet aggregation pathways that collagen is responsible for. (wikipedia.org)
This enzyme may have the potential to inhibit platelet formation with certain pathways that were previously determined that the toxin had no effect on. (wikipedia.org)

Blockade of the platelet Fc-receptor or enzymatic cleavage of IgG abolished platelet activation and aggregation. (lu.se)
SBSEC mediates platelet aggregation in an IgG and IgG-Fc-receptor dependent manner. (lu.se)
The Fc-IgG-receptor pathway was shown essential for platelet activation and aggregation. (lu.se)
It adds SBSEC to a group of bacteria that activate and aggregate platelets via the platelet Fc-receptor. (lu.se)
Qin R , Zhu H , Wang F , Song M , Lin P , Xing Y , Zhang W , Zhong M , Wang Z , . Platelet activation in diabetic mice models: the role of vascular endothelial cell-derived protein disulfide isomerase-mediated GP IIb/IIIa receptor activation. (aging-us.com)
We sought to extend the receptor-desensitization paradigm for use with a cultured cell system, in which an intracellular calcium signal rather than a contractile response might be used as an index of receptor activation. (aspetjournals.org)
Conclusion: This work emphasizes that prior platelet activation can be reversed, whereafter platelets can be reactivated through a different receptor. (reading.ac.uk)
Here, we report for the first time that human platelets contain the glucocorticoid receptor (GR) as identified by a combination of biochemical and functional techniques. (ashpublications.org)
The apparently anomalous binding data were clarified by the fact that washed platelets (1) contained mineralocorticoid receptor and that (2) it was associated with GR. Taken together, our data suggest that platelet GR forms a heterodimeric complex with the mineralocorticoid receptor that is susceptible to differential activation by specific receptor ligands. (ashpublications.org)
DLL-4, in turn, instigated neighbouring platelets to switch to 'activated' phenotype through cleavage of Notch receptor and release of its intracellular domain (NICD), which was averted by inhibition of γ-secretase and phosphatidylinositol-3-kinase (PI3K). (elifesciences.org)
OBJECTIVE: The receptor-like protein-tyrosine phosphatase (PTP) CD148 and the nontransmembrane PTP1-B have been shown to be net positive regulators of Src family kinases in platelets. (ox.ac.uk)
In the present study, we compared the relative contributions of these PTPs in platelet activation by the major glycoprotein, glycoprotein VI, α(IIb)β(3), and C-type lectin-like receptor 2 (CLEC-2). (ox.ac.uk)
The released ADP acts on the P2Y12 receptor on other platelets, thereby activating them and recruiting them to the site of injury. (msdmanuals.com)

If operative in vivo, these anti-platelet effects of bedaquiline may contribute to ameliorating the risk of TB-associated cardiovascular disease, but this remains to be explored in the clinical setting. (up.ac.za)
Thus, Notch pathway can be a potential anti-platelet/anti-thrombotic therapeutic target. (elifesciences.org)
Advances in the discovery of novel anti-platelet therapeutics remains an unmet need. (elifesciences.org)

Conditions associated with decreased platelet aggregation include suspected hereditary and acquired disorders of platelet function. (medscape.com)

We'll be discussing endotheliopathy and platelet dysfunction in Lassa fever. (cdc.gov)
Sarah Gregory] Endotheliopathy and platelet dysfunction are outcomes of Lassa fever. (cdc.gov)
Sarah Gregory] Explain to us what endotheliopathy and platelet dysfunction is. (cdc.gov)

Current therapies still fail to prevent thrombotic events in numerous patients, indicating that the mechanisms modulating platelet response during activation need to be clarified. (nature.com)
In spite of this, current antithrombotic approaches still fail to prevent thrombotic coronary events in a substantial number of patients 5 , indicating that the complex mechanisms modulating platelet response during activation are not completely understood. (nature.com)
To the best of our knowledge, this is the first study that reports on platelet interactions of SBSEC-isolates other than Streptococcus gallolyticus subspecies gallolyticus as well as the first study to report of mechanisms of platelet interaction of SBSEC-isolates. (lu.se)
Once activated, platelets have two major mechanisms to recruit additional platelets to the growing hemostatic plug. (medscape.com)
70%. Severe cases exhibit abnormal coagulation, endothelial barrier disruption, and dysfunctional platelet aggregation but the underlying mechanisms remain poorly understood. (cdc.gov)
However, the mechanisms of surface-induced platelet activation have not been fully been elucidated or visualized so far. (elsevierpure.com)
Molecular mechanisms underlying CVT, potentially involving pathological platelet activation, are currently unknown. (isth.org)
Despite some benzodiazepine analogues are reported to inhibit platelet aggregation through different mechanisms, there is relatively rare information on the study of GABA in platelet function. (tmu.edu.tw)
Overview of Hemostasis Hemostasis, the arrest of bleeding from an injured blood vessel, requires the combined activity of Vascular factors Platelets Plasma coagulation factors Regulatory mechanisms counterbalance. (msdmanuals.com)

Thrombocytopenia is a common feature of hemorrhagic fevers and vascular permeability disorders ( 8 ), but the decrease in platelet counts in acute LF is not low enough to cause spontaneous hemorrhage. (cdc.gov)

Using a platelet‑aggregation assay, it was revealed that LGP significantly inhibited platelet aggregation induced by ADP, U46619 and arachidonic acid. (spandidos-publications.com)
Compared with the normal diet group, the diabetic group had significantly increased plasma EMP-PDI content and accelerated platelet activation by increased GP IIb/IIIa expression. (aging-us.com)
However, diabetic patients have significantly higher platelet aggregation and activation than non-diabetic patients, including those undergoing dual antiplatelet therapy [ 4 - 6 ]. (aging-us.com)
Platelets were the only peripheral blood cells that were significantly elevated in number in CAPs-exposed mice. (cdc.gov)
PRP samples showed higher significantly platelet concentrations than peripheral blood samples (2,677,583 and 683,680 respectively). (bvsalud.org)

Stehbens and Biscoe, 1967 ), platelet shape change was, and still is, generally regarded to be the initial stage of platelet activation. (nature.com)
Observation by TEM indicates that internal granules coalesce in the center of the platelet accompanied by pseudopodial growth in the early stage of platelet activation. (elsevierpure.com)

In conclusion, the data presented here demonstrated that LGP, a natural compound from C. nudiflora Hook, inhibited the development of platelet aggregation and amplification of platelet activation. (spandidos-publications.com)
Disorders of amplification of platelet activation are the most common hereditary intrinsic platelet disorders and produce mild bleeding. (msdmanuals.com)

A critical issue in such cases is the possibility to assess platelet activation extent before tissue damage occurs, i.e. before myocardial necrosis. (nature.com)

The morphological and functional changes of platelets require a drastic remodeling of the actin cytoskeleton regulated by numerous actin-binding proteins and signaling molecules such as the family of Rho-GTPases. (uni-muenchen.de)
Platelet activation allows binding of these proteins, which bridges adjacent platelets. (medscape.com)
In Sierra Leone during 2015-2018, we assessed LF patients' day-of-admission plasma samples for levels of proteins necessary for coagulation, fibrinolysis, and platelet function. (cdc.gov)
Levels of pro- apoptotic Bax and anti-apoptotic Bcl-2 proteins were determined by densitometric analysis of western blots performed with platelet lysates. (ashpublications.org)

These interactions further activate platelets. (medscape.com)
PCs contain leukocytes, which can pose potential side effects and activate platelets, reducing the efficacy of platelet transfusion. (phcogj.com)

The platelet GP IIb/IIIa complex mediates platelet-to-platelet interactions (platelet aggregation). (medscape.com)

Our study presents compelling evidence in support of non-canonical juxtacrine Notch signaling within platelet aggregates that synergizes with physiological agonists to generate occlusive intramural thrombi. (elifesciences.org)
Thrombogenicity was assessed by carotid artery occlusion, fibrinolytic variables and platelet-monocyte aggregates. (anma.it)
DEP, but not CB or DQ12, increased platelet-monocyte aggregates. (anma.it)

Twenty-six isolates of the four most common species and subspecies of SBSEC identified in bacteremia were collected, and interactions with platelets were investigated in platelet rich plasma (PRP) from three donors. (lu.se)

Rho-kinase regulates a second pathway that involves activation of LIM-kinases (LIMKs) and subsequent phosphorylation and inactivation of cofilin, an actin dynamizing protein. (uni-muenchen.de)
The signaling pathway Rho-kinase/LIMKs/cofilin phosphorylation during platelet activation and the question, how the phosphorylation of cofilin affects the actin dynamics underlying platelet activation, has not previously been studied. (uni-muenchen.de)
These ADP-selective inhibitory effects of bedaquiline on platelet activation were mimicked by wortmannin, an inhibitor of phosphatidylinositol 3-kinase (PI3-K), implicating PI3-K as being a common target of both agents, a contention that was confirmed by the observed inhibitory effects of bedaquiline on the phosphorylation of Akt1 following activation of platelets with ADP. (up.ac.za)
Specific Aim 2 (2nd year): To determine whether inhibition of NF-B (p65/p50) (IKKβ phosphorylation, IκBα degradation, and p65 phosphorylation) contributes to GABA-mediated inhibitory effect in platelet activation, and to clarify the relationship between NF-κB and GABA-mediated signaling events (i.e., cyclic nucleotides, PLCγ2-IP3-PKC cascades, and MAPK, etc). (tmu.edu.tw)
However, they exhibited a marginal reduction in α(IIb)β(3)-mediated Src family kinase activation and tyrosine phosphorylation. (ox.ac.uk)

The hemostatic system consists of platelets, coagulation factors, and the endothelial cells lining the blood vessels. (medscape.com)
Platelets, endothelial cells, and leukocytes become activated and, in turn, initiate the coagulation cascade while releasing various mediators. (medscape.com)

Inhibition of the Rho-kinase/LIMK-1 pathway unmasked cofilin dephosphorylation suggesting that during shape change the simultaneous activation of a cofilin phosphatase counteracts the effect of LIMK-1 for phosphorylating cofilin. (uni-muenchen.de)
The metalloproteinase disintegrin-like domain and the cysteine-rich domain of the enzyme are responsible for the enzyme's hemorrhagic effects on organisms via inhibition of platelet aggregation. (wikipedia.org)

Platelets contain two unique types of granules: alpha granules and dense granules. (medscape.com)
During activation, the granules are centralized and their contents are discharged into the lumen of the open canalicular system, from which they are then released to the exterior (the release reaction). (medscape.com)
As a result of comparative observation of an adherent platelet on polycarbonate (PC) and on amorphous carbon (a-C:H), it was found that internal granules release was inhibited more remarkably on a-C:H coating rather than on PC. (elsevierpure.com)
Specific Aim 1 (1st year): To further quantify the levels of GABA by LC-MS/MS and capillary zone electrophoresis (CZE) and elucidate their specific localization (i.e.,  granules, dense granules or open canalicular system) in platelets by transmission electron microscope. (tmu.edu.tw)
PRP acts by accelerating the process of tissue healing through releasing growth factors inside platelet α-granules 21 . (bvsalud.org)

Like Rho-kinase activation, it was also found that LIMK-1 activation was independent and upstream of integrin IIbβ3 activation. (uni-muenchen.de)
Human and mouse platelets responded to dRP treatment with a sizeable increase in reactive oxygen species (ROS) generation and the pre-treament with the antioxidant apocynin abolished the effect of dRP on aggregation and integrin activation. (bath.ac.uk)
The cysteine-rich domain was shown to have two sequences that cause an interaction which prevents alpha-2/beta-1 integrin expressing K562 cells and platelets from binding to collagen. (wikipedia.org)
Compatible with decreased integrin activation, platelet morphology was reversed. (reading.ac.uk)
Gain-of-Function Mutation in Filamin A Potentiates Platelet Integrin α IIb ß 3 Activation. (bvsalud.org)

Serum-induced mitogenicity was dependent on platelet-derived growth factor (PDGF). (wustl.edu)

The purpose of this study was to investigate the release of Endothelial microparticle (EMP)-associated protein disulfide isomerase (PDI) after endothelial cell injury induced in diabetes and the changes in platelet activation. (aging-us.com)

Interestingly, it has been shown that platelets contain a broad spectrum of RNA molecules, including, in addition to mRNAs and miRNAs, also pre-mRNAs and a role of mRNA splicing in regulation of platelet protein synthesis has been proposed 18 , 19 . (nature.com)
Thus, platelets may be an ideal target for the study of the non-genomic functions (i.e., regulation of platelet activation, apoptosis, and autophagy) of NF-B in anucleated cells. (tmu.edu.tw)
Our preliminary results also demonstrated that GABA plays an important role in regulation of platelet activation and apoptosis. (tmu.edu.tw)

For IE-pathogens, the capacity to activate and aggregate platelets is believed to be an important virulence mechanism. (lu.se)
IMPORTANCE The capacity of bacteria to activate and aggregate platelets is believed to contribute to the pathogenesis of IE. (lu.se)
Severe abnormalities in platelet function, such as Bernard-Soulier syndrome, Glanzmann's thrombasthenia, or platelet storage-pool deficiency, are characterized by the inability of platelets to aggregate in response to certain agonists. (nature.com)
Both PTPs are required for optimal platelet activation and aggregate formation under high arterial shear rates. (ox.ac.uk)

Since then, the initial decrease in light transmission detected in aggregometry is used as a measure for the extent of platelet shape change. (nature.com)

Platelet disorders lead to defects in primary hemostasis and produce signs and symptoms different from coagulation factor deficiencies (disorders of secondary hemostasis). (medscape.com)
These defects were associated with reduced activation of Src family kinase and spleen tyrosine kinase, suggesting a causal relationship. (ox.ac.uk)
Hereditary intrinsic platelet disorders can involve defects in any of these substrates and steps. (msdmanuals.com)
Severe bleeding tendency starting at delivery or later and defects in platelet activation. (lu.se)

The evidence that platelets are capable of de novo protein synthesis in response to stimuli raised the issue of how megakaryocyte-derived mRNAs are regulated in these anucleate cell fragments. (nature.com)
Evidence that platelets are capable of de novo protein synthesis 17 also raised the issue of whether resident mRNAs are regulated in circulating platelets and, if so, why. (nature.com)
The impaired homeostasis and platelet dysfunction implicate alterations in the protein C pathway, which might contribute to the loss of endothelial barrier function in fatal infections. (cdc.gov)
When this variant of the protein was inserted into human blood, ADP stimulated platelet aggregation was inhibited. (wikipedia.org)
5 Since changes in de novo protein synthesis are the basis for glucocorticoid effectiveness, the lack of a modulatory effect on platelet functions is not surprising given that these cells have been regarded as incapable of synthetic activity. (ashpublications.org)
We also evaluate whether GABA regulates the NF-B translocation or mtDNA-encoded protein expressions in platelets. (tmu.edu.tw)
Dominant role of the protein-tyrosine phosphatase CD148 in regulating platelet activation relative to protein-tyrosine phosphatase-1B. (ox.ac.uk)
Platelet-dependent neutrophil function is dysregulated by M protein from Streptococcus pyogenes. (lu.se)

Platelets play a primary role in this process, interacting with subendothelium-bound von Willebrand factor (vWf) via the membrane glycoprotein (GP) Ib complex. (medscape.com)
METHODS AND RESULTS: PTP-1B-deficient mouse platelets responded normally to the glycoprotein VI-specific agonist collagen-related peptide and antibody-mediated CLEC-2 activation. (ox.ac.uk)
In contrast, CD148-deficient platelets exhibited a dramatic reduction in activation by glycoprotein VI and α(IIb)β(3) and a marginal reduction in response to activation by CLEC-2, which was further enhanced in the absence of PTP-1B. (ox.ac.uk)

Platelet inhibitory effect of clopidogrel in patients treated with omeprazole, pantoprazole, and famotidine: a prospective, randomized, crossover study. (medscape.com)

The authors evaluated blood cell parameters and markers of platelet activation in mice exposed to concentrated ambient particulate matter (CAPs) from the San Joaquin Valley of California, a region with severe particulate matter (PM) pollution episodes. (cdc.gov)

This was also seen when preactivated platelets, which cannot undergo further morphological changes, were used, and when platelets were activated in the presence of shape-change inhibitors such as cytochalasin D and vincristine. (nature.com)

Since the concentrations of GABA were approximated at 98.6±33.9 ng/ml (~0.7-1.3 M) in human plasma, the pharmacological concentration of GABA (0.5~1 μM) employed to inhibit platelet aggregation are reasonable. (tmu.edu.tw)
Davis, DH, Rapp, UR & Davidson, NO 1991, ' Retinoic acid and transforming growth factor β differentially inhibit platelet-derived-growth-factor-induced Ito-cell activation ', Biochemical Journal , vol. 278, no. 1, pp. 43-47. (wustl.edu)

These flow cytometric techniques have the potential for detection of in vivo platelet activation in horses at risk of developing thrombotic disorders. (avma.org)
This study investigated the in vivo effect of alum on platelet aggregation and bleeding time in rabbits. (who.int)
contradiction in the mechanism of action of alum, we evaluated the in vivo effect of Alum (aluminium potassium sulfate) is a alum in terms of collagen-induced platelet food additive and traditional remedy used to aggregation and bleeding time. (who.int)

Terminal platelet production and platelet activation involve considerable cytoskeletal reorganization. (umich.edu)

Because the initial decrease in light transmission in platelet aggregometry is attributed to platelet shape change, it is widely held that platelet shape change is a prerequisite for platelet aggregation. (nature.com)

In addition, when platelets are activated, negatively charged phospholipids move from the inner to the outer leaflet of the membrane bilayer. (medscape.com)
Many of the features of apoptosis such as membrane fragmentation, microvesiculation and phosphatidylserine (PS) exposure are observed during platelet activation to a procoagulant state, raising the possibility that apoptosis may regulate platelet function. (ashpublications.org)
With this model we observe that the confining membrane suppresses the instability more readily for smaller marginal bands, thereby increasing the stability of platelets compared to their precursors. (umich.edu)

Thrombocytopenia and platelet dysfunction contribute to hemorrhagic complications observed in MDS. (ashpublications.org)

Specific Aim 4 (3rd year): To investigate the pivotal roles of NF-B regulation in Bax-associated apoptotic signals (i.e., mPT, AIF, Endo G, apoptosome formation, caspase activation, and mtDNA fragmentation, etc) in human platelets, and concurrently to compare the differences of apoptotic events in platelets isolated from NF-B knockout (NF-B-/-) and wild type mice. (tmu.edu.tw)

The abilities of the PAR 1 -targeted agents to desensitize or block PAR 1 in the HEK cell assay were compared with their activities in a human platelet aggregation assay. (aspetjournals.org)

The EMP-PDI content and GP IIb/IIIa expression of mice platelets were determined. (aging-us.com)
In contrast, prophylactic GPIIb/IIIa blockade abolished platelet consumption, CVT and death. (isth.org)
These results point to aberrant platelet activation as a major trigger of CVT and suggests targeting GPIIb/IIIa or CLEC2-ITAM signaling as a potential therapeutic option in foudroyant CVT. (isth.org)

Platelet activation in atherogenesis associated with low-grade inflammation. (ox.ac.uk)
Platelets produce a number of agents contributing to the systemic low-grade inflammation implicated in atherogenesis. (ox.ac.uk)
The design of new therapeutic strategies targeting platelets and their impact in atherosclerosis-related low-grade inflammation are in the center of current cardiovascular research. (ox.ac.uk)

Results -Anti-human thrombospondin antibody failed to bind to equine platelets. (avma.org)

These results suggest that CD69 may function as an activating molecule on platelets, as on lymphocytes, and point toward a more general role of this surface dimer in signal transduction. (nih.gov)
These results indicate that RNA splicing events occur in platelets during activation and that maturation of specific pre-mRNAs is part of the activation cascade, contributing to a dynamic fine-tuning of the transcriptome. (nature.com)
Results: Platelet aggregation was dysregulated in severe anaphylaxis at T0, but not in moderate anaphylaxis, sepsis or trauma. (edu.au)
These results indicate that platelet shape change is not a prerequisite for aggregation and that the signal widely believed to represent shape change reflects platelet microaggregation instead. (nature.com)
Exposure of mice to concentrated ambient particulate matter results in platelet and systemic cytokine activation. (cdc.gov)
These disorders are suspected in patients with lifelong bleeding disorders who have normal platelet counts and coagulation study results. (msdmanuals.com)

Anatomy14

Organisms7

Diseases18

Chemicals and Drugs130

Analytical, Diagnostic and Therapeutic Techniques and Equipment22

Phenomena and Processes31

Disciplines and Occupations1

Information Science2

Health Care1

Induced platelet aggregation7

Blood Platelets3

Flow cytometry12

Thrombin22

Fibrinogen11

Secretion9

Adhesion11

Vitro4

Thrombus15

Thrombosis14

Receptors7

Involved in platelet aggregation and activation3

Adenosine4

Role for platelet2

Stimulation3

Reactivity8

Molecular mechanisms of platelet activation2

Pathways6

Receptor13

Anti-platelet3

Disorders of Platelet Function1

Endotheliopathy and Platelet Dysfunction3

Mechanisms9

Vascular1

Significantly5

Stage of platelet activation2

Amplification of platelet activation2

Assess platelet activation1

Proteins4

Activate platelets2

Mediates platelet1

Aggregates3

Interactions with platelets1

Phosphorylation5

Endothelial cells2

Inhibition2

Granules5

Integrin5

PDGF1

Changes in platelet1

Regulation of platelet3

Aggregate4

Extent of platelet1

Defects4

Protein8

Glycoprotein3

Inhibitory effect1

Markers1

Inhibitors1

Inhibit2

Vivo3

Cytoskeletal reorganization1

Aggregometry1

Membrane3

Dysfunction1

Formation1

Aggregation assay1

IIIa3

Inflammation3

Antibody1

Results6