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Демонстрация коагулативной и тромбоцитной активации Рикитсии у пациентов со пятнистой температурой в Средиземном море.

Недавно была продемонстрирована эдотелиальная травма в vivo, вызванная Рикитсией Конори, этиологическим агентом средиземноморской жары. Мы пытались определить, может ли тромб и/или коагулирующая активация в vivo быть продемонстрирована в острой фазе MSF путем измерения основного метаболита тромбоксана (TX) в моче (11-дегидро-ТВБ2) и плазменного протромбинного фрагмента 1 + 2, уровни которого отражают активацию протромбина в тромбин. Кроме того, мы измерили плазменный эндотелин-1 как маркер эндотелиальной дисфункции. Наши результаты позволяют получить биохимические данные о случаях активации тр

Совпадение в аннотации оригинала
Endothelial injury in vivo induced by Rickettsia Conorii, the etiologic agent of Mediterranean Spotted Fever (MSF) has been recently demonst … othelial dysfunction. Our results provide biochemical evidence for the occurrence of TXA2-dependent platelet activation and thrombin generation in vivo, together with endothelial dysfunction. These phenomena could account for clinical manifestations of MSF, such as vasculitis and focal microthrombus formation. These results could also provide a rationale for testing …

Platelet surface glycoproteins. Studies on resting and activated platelets and platelet membrane microparticles in normal subjects, and observations in patients during adult respiratory distress syndrome and cardiac surgery.

The accurate definition of surface glycoprotein abnormalities in circulating platelets may provide better understanding of bleeding and thrombotic disorders. Platelet surface glycoproteins were measured on intact platelets in whole blood and platelet membrane microparticles were assayed in cell-free plasma using 125I-monoclonal antibodies. The glycoproteins (GP) studied were: GP Ib and GP IIb-IIIa, two of the major intrinsic plasma membrane glycoproteins; GMP-140, an alpha-granule membrane glycoprotein that becomes exposed on the platelet surface following secretion; and thrombospondin (TSP),

Targeting Platelet Activating Factor Signaling for Therapeutic Benefits in Neurodegenerative Disorders.

Neurodegenerative disorders (NDs), including dementia, Alzheimer's disease (AD), and Parkinson's disease (PD), are age-related diseases closely associated with chronic inflammation, oxidative stress, gene mutations, autoimmune-derived inflammation, and other external risk factors. They are characterized by progressive neuronal loss, cognitive decline, and/or motor dysfunction, with chronic inflammation being a key player in intensifying NDs' occurrence. One of the most important molecular inflammatory mediators linking inflammation to NDs is the platelet-activating factor (PAF) and its pivotal

Effect of the Polymorphic Variant p.D1472H on the Platelet-Dependent VWF Activity Assays.

BACKGROUND: The von Willebrand factor (VWF) p.D1472H variant has been shown to artificially lower ristocetin cofactor (VWF:RCo) levels because of impaired VWF binding to ristocetin. Understanding the variant's effect on platelet-dependent VWF activity assays is crucial for avoiding over- or misdiagnosis of von Willebrand disease. AIM: To determine whether p.D1472H affects the VWF:GPIbR latex immunoassay (LIA). METHODS: We investigated 150 subjects for VWF:Ag and platelet-dependent VWF activity using four commercially available assays: VWF:GPIbR LIA, VWF:GPIbR chemiluminescence immunoassay (C

Investigations into the role of platelet-activating factor in the peri-conception period of the mare.

IN BRIEF: In many mammals, the lipid platelet-activating factor (PAF) has important functions in female reproduction and fertility. This study shows that PAF is present in the reproductive tissues of mares and is involved in processes related to ovulation and early pregnancy. ABSTRACT: Platelet-activating factor (PAF) has been implicated in a number of reproductive processes ranging from ovulation to embryo motility but has not been widely explored in the mare. To identify the presence and examine the role of PAF in the equine periconception processes, targeted mass spectrometry coupled with

Activation of platelets and the complement system in mice with Schistosoma-induced pulmonary hypertension.

Schistosomiasis-induced pulmonary hypertension (PH) presents a significant global health burden, yet the underlying mechanisms remain poorly understood. Here, we investigate the involvement of platelets and the complement system in the initiation events leading to Schistosoma-induced PH. We demonstrate that Schistosoma exposure leads to thrombocytopenia, platelet accumulation in the lung, and platelet activation. In addition, we observed increased plasma complement anaphylatoxins C3a and C5a, indicative of complement system activation, and elevated platelet expression of C1q, C3, decay activat…

Advance in the pathogenesis of otitis media with effusion induced by platelet-activating factor.

A non-suppurative inflammatory disease of the middle ear with middle ear effusion and conductive hearing loss is called otitis media with effusion. Poor eustachian tube function, immunological factors, viral factors, and other factors are primarily involved in its pathophysiology, which has not yet been completely understood. Several researcher scholars have recently studied platelet-activating factor and they found that platelet-activating factor is closely associated to the occurrence, development, and outcome of otitis media with effusion. Platelet-activating factor is a significant element

Platelet to albumin ratio is an independent indicator for disease activity in ankylosing spondylitis.

The objective of this study is to characterize the association between platelet to albumin ratio (PAR) and disease activity in patients with ankylosing spondylitis (AS) and axial psoriatic arthritis (axPsA). Baseline platelet count, albumin, PAR, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), Bath ankylosing spondylitis disease index (BASDAI), Bath ankylosing spondylitis functional index (BASFI), and ankylosing spondylitis disease activity score (ASDAS) were collected from patients with a definitive diagnosis of AS or axPsA. Spearman's correlation analysis, quantile regression

Platelet activating factor in the eye: Physiological roles, diseases and future perspectives.

Platelet Activating Factor (PAF) is a known phospholipid mediator of inflammation. Since its first description in 1972, it has emerged as a key regulator of vital cellular signaling functions, as proliferation, cell adhesion, and apoptosis. Evidence suggests that interactions between PAF and its receptor (PAFR) play a critical role in nervous system tissues, including the retina. The retina is a very important constituent of the visual system, along with the cornea, sclera, choroid, iris, and ciliary body, that acts synergistically to provide vision and to maintain optical homeostasis. There i

Does platelet activity play a role in the pathogenesis of idiopathic ischemic priapism?

PURPOSE: Mean platelet volume (MPV) is used to measure platelet size and is defined as a potential marker of platelet reactivity. Higher MPV levels have been defined as a risk factor for increased incidence of intravascular thrombosis and its associated diseases. We aimed to determine whether a relationship exists between the MPV and veno-occlusive component of idiopathic ischemic priapism (IIP). MATERIALS AND METHODS: Between 2010 and 2014, 38 subjects were analyzed in two groups. One was composed of 15 patients with diagnosis as IIP in our institute, and the other contained 23 healthy contr

Neutrophil- and platelet-to-lymphocyte ratios are correlated with disease activity in rheumatoid arthritis.

BACKGROUND: Both neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are reported to be increased in various inflammation-related diseases, but their clinical significance in rheumatoid arthritis (RA) remains unclear. The aim of the present study was to explore whether NLR and PLR were candidate indices for RA disease-activity assessment. METHODS: The medical records of 128 RA patients and 78 healthy individuals were retrospectively reviewed. Correlations of NLR and PLR with the disease activity of RA were evaluated. RESULTS: NLR and PLR were increased significantly i

Antimicrobial/anti-biofilm activity of expired blood platelets and their released products.

INTRODUCTION: Although platelets are not part of the classical immune system, they have many features that indicate their role in the anti-infective host defense. They come into interactions with microorganisms, which results in co-aggregation and co-adhesion or destruction of the microbes due to the action of antimicrobial peptides released from platelets.The aim of this study was to evaluate the killing effect of platelets against planktonic and biofilm cultures of Staphylococcus aureus and to test their synergy with antibiotics. MATERIALS AND METHODS: S. aureus ATCC 29213; platelet rich pl

Mean platelet volume: a controversial marker of disease activity in Crohn's disease.

BACKGROUND: We investigated and compared the capacity of mean platelet volume (MPV) and other inflammatory markers in detecting Crohn's disease (CD) activity and differentiating CD patients from healthy controls. METHODS: MPV, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and white blood cells were measured in 61 CD patients and 50 healthy subjects. Disease activity was assessed by the Crohn's Disease Activity Index. RESULTS: A significant decrease in MPV was noted in patients with CD compared with healthy controls (P <0.0001), but statistical difference was not found betwee

Platelet-activating factor stimulates sodium-hydrogen exchange in ventricular myocytes.

Sodium-hydrogen exchanger (NHE), the principal sarcolemmal acid extruder in ventricular myocytes, is stimulated by a variety of autocrine/paracrine factors and contributes to myocardial injury and arrhythmias during ischemia-reperfusion. Platelet-activating factor (PAF; 1-o-alkyl-2-acetyl-sn-glycero-3-phosphocholine) is a potent proinflammatory phospholipid that is released in the heart in response to oxidative stress and promotes myocardial ischemia-reperfusion injury. PAF stimulates NHE in neutrophils and platelets, but its effect on cardiac NHE (NHE1) is unresolved. We utilized quiescent gu

Isolation of Bioactive Compounds That Relate to the Anti-Platelet Activity of Cymbopogon ambiguus.

Infusions and decoctions of Cymbopogon ambiguus have been used traditionally in Australia for the treatment of headache, chest infections and muscle cramps. The aim of the present study was to screen and identify bioactive compounds from C. ambiguus that could explain this plant's anti-headache activity. A dichloromethane extract of C. ambiguus was identified as having activity in adenosine-diphosphate-induced human platelet aggregation and serotonin-release inhibition bioassays. Subsequent fractionation of this extract led to the isolation of four phenylpropenoids, eugenol, elemicin, eugenol

The induction of an angiogenic response in corneal myofibroblasts by platelet-activating factor (PAF).

PURPOSE: Although the exact mechanisms underlying corneal neovascularization remain unclear, cytokines and growth factors play an important role in their development. We have shown previously that the inflammatory mediator platelet-activating factor (PAF) is a potent inducer of corneal neovascularization in vivo. In this study, we investigate the role of stromal myofibroblasts in neovascularization and the effect of PAF on this process. METHODS: Myofibroblasts were obtained from rabbit corneal keratocytes and identified with anti-α-SMA antibody. Cells were treated with PAF (100 nM) for 24 hr.

Differential binding of ICln in platelets to integrin-derived activating and inhibitory peptides.

The capacity of platelets to form a thrombus is mediated by integrin alpha(IIb)beta(3). The cytoplasmic tail of alpha(IIb) contains a highly conserved motif, (989)KVGFFKR(995), which plays a critical role in regulating integrin activation and acts as a recognition site for various intracellular proteins, e.g. CIB1, PP1, ICln and RN181. Previously, we demonstrated that a cell-permeable integrin-derived activating (IDA) peptide, KVGFFKR, induces platelet activation, whereas an integrin-derived inhibitory (IDI) peptide, KVGAAKR, is antithrombotic. To elucidate the molecular mechanism underlying t…

Effects of activated platelet concentrates on human primary cultures of fibroblasts and osteoblasts.

BACKGROUND: Platelet alpha granules contain growth factors released into the surrounding environment during activation. This property has been used in clinical medicine to accelerate the repair process by activating in vitro autologous platelets with thrombin and has also been proposed to promote the proliferation of bone cells. The aim of this research was to assess the effect of platelet concentrates activated with thrombin on human gingival fibroblasts and human osteoblasts from trabecular bone. METHODS: Platelet concentrates, activated with bovine thrombin, were added to the cells in seru

Differential role of platelet-activating factor in gastric mucosal ulcer healing.

Platelet-activating factor (PAF) is a potent phospholipid-derived messenger involved in a number of diverse pathological conditions, including mediation of inflammatory cascades associated with wound healing. In this study, we investigated the effect of a specific PAF antagonist, BN52020, on the course of experimentally induced gastric mucosal ulcer healing by analyzing apoptotic processes and the mucosal expression of TNF-alpha, COX-2, and the activity of inducible nitric oxide synthase (NOS-2). Groups of rats were intragstrically pretreated with BN52020 either 24 and 4 h before acetic acid i

A hereditary bleeding disorder of dogs caused by a lack of platelet procoagulant activity.

We have discovered a novel canine hereditary bleeding disorder with the characteristic features of Scott syndrome, a rare defect of platelet procoagulant activity. Affected dogs were from a single, inbred colony and experienced clinical signs of epistaxis, hyphema, intramuscular hematoma, and prolonged bleeding with cutaneous bruising after surgery. The hemostatic abnormalities identified were restricted to tests of platelet procoagulant activity, whereas platelet count, platelet morphology under light microscopy, bleeding time, clot retraction, and platelet aggregation and secretion in respon