Search results for "Platelet"
showing 10 items of 786 documents
Synthesis and characterization of Sn(IV) complexes of lower rim 1,3-diacid derivative of calix[4]arene and their protective effects on tissue oxidati…
2005
The two Sn(IV) complexes synthesized using calix[4]arene-1,3-di-acid derivative were characterized by analytical, 1H, 13C and 119Sn NMR, matrix assisted laser desorption ionization mass, and 119Sn Mossbauer techniques and found that the complexes are tetranuclear possessing structurally two different types of tin centers. These complexes were evaluated for their protective value against blood and tissue oxidative stress in lead exposed male albino rats of Wistar strain. The results suggest that the two tin complexes significantly protect changes in lead induced biochemical variables indicative of heme synthesis pathway and exhibit only moderate effect on tissue oxidative stress. The benefic…
Synthesis and Evaluation of a Novel Series of Pyrrolizine Derivatives as Dual Cyclooxygenase-1 and 5-Lipoxygenase Inhibitors
1997
The aim of our study was to investigate structure activity relationship following the replacement of the 6-phenyl substituent at the 6,7-diaryl-2,3-dihydropyrrolizine template by various heteroaromatic residues. In this context we developed a new, efficient, and highly sensitive test method for the screening of dual cyclooxygenase-1 (COX-1) and 5-lipoxygenase (5-LOX) inhibitors. We used human platelets as a source of COX-1 and human PMNLs as a source of 5-LOX. Both cell types were isolated from the same volume of blood. PGE2 and LTB4 respectively were determined by highly selective and sensitive ELISA kits, using monoclonal antibodies. For a single determination at most 0.5 mL whole blood i…
Anti-inflammatory and analgesic activity of a novel inhibitor of microsomal prostaglandin E synthase-1 expression
2009
Abstract In a previous study, we reported a new γ-hydroxybutenolide derivative, 4-benzo[ b ]thiophen-2-yl-3-bromo-5-hydroxy-5 H -furan-2-one (BTH), as inhibitor of microsomal prostaglandin E synthase-1 (mPGES-1) expression in lypopolysaccharide (LPS) stimulated RAW 264.7 and TPH-1 cells, without affecting cyclooxygenase-2 (COX-2). In this study, we evaluated the in vivo effect of BTH on some acute and chronic inflammatory animal models in relation to its inhibitory profile on mPGES-1 expression. In the zymosan-induced mouse air pouch model, BTH produced a dose-dependent inhibition of prostaglandin E 2 (PGE 2 ) production and mPGES-1 protein expression in pouch exudates without any effect on…
Amyloid precursor protein in platelets: A peripheral marker for the diagnosis of sporadic AD
2001
BACKGROUND: An altered pattern of amyloid precursor protein (APP) forms consisting in a reduced ratio between the upper (130 kDa) and the lower (106 to 110 kDa) immunoreactivity bands has been described in platelets of patients with AD. OBJECTIVE: To evaluate the sensitivity and the specificity of platelet APP forms' ratio (APPr) as a marker for AD. METHODS: Eighty-five patients with probable AD and 95 control subjects (CON), including healthy individuals and neurologic patients, entered the study. Platelet APPr was evaluated by means of Western Blot analysis and immunostaining in the whole platelet homogenate, and calculated by the ratio between the optical density (OD) of the upper (130 k…
Incorporation and metabolism of dietary trans isomers of linolenic acid alter the fatty acid profile of rat tissues
2000
To study the influence on lipid metabolism and platelet aggregation of the fatty acid isomerization that occurs during heat treatment, weanling rats were fed for 8 wk a diet enriched with 5% isomerized (experimental group) or normal (control group) canola oil. Geometrical isomers of alpha-linolenic acid representing 0.2 g/100 g of the experimental diet were incorporated into liver, platelets, aorta and heart, at the expense of their cis homologue and of 18:2(n-6). The major isomer, 9c,12c,15t-18:3, was also metabolized to 5c,8c,11c,14c,17t-20:5 and to an unknown compound, found in liver, platelets and aorta, which has been identified tentatively as 7c, 10c,13c,16c,19t-22:5. The greater 20:4…
In-vitro and Ex-vivo Inhibition of Blood Platelet Aggregation by Naftazone
1996
Abstract Because of the considerable interest in the role of platelets and antiplatelet therapy in cardiovascular disease, including the aggregation of platelets to each other during arterial thrombosis and atherogenesis, we have studied the effect of naftazone (Etioven), an original vasculotropic drug on platelet aggregation. Rat and human platelets were prepared and incubated in-vitro with different concentrations of naftazone. We found that naftazone inhibited both platelet secretion and aggregation in platelet-rich plasma (PRP) and washed platelets after stimulation with thrombin or ADP. Rats were also treated intraperitoneally for five days with various naftazone doses (0.125-10 mg kg−…
Cortisol, Platelet Serotonin Content, and Platelet Activity in Patients With Major Depression and Type 2 Diabetes
2015
OBJECTIVE Hypothalamic-pituitary-adrenal system dysfunction, serotonergic system alterations, and enhanced platelet activity may contribute to the increased cardiac risk in depression. This exploratory study examined associations between cortisol parameters, platelet serotonin (5-HT) content, and platelet activity markers in patients with newly diagnosed major depression (MD) and/or Type 2 diabetes (T2DM) compared with healthy controls. METHODS We compared cortisol awakening response (CAR), diurnal decrease in salivary cortisol concentrations (slope), platelet 5-HT, and platelet markers (CD40, CD40 ligand [CD40L], soluble CD40L, CD62P, β-thromboglobulin, and platelet factor-4) in 22 T2DM pa…
Analysis and comparison of autologous platelet-rich plasma preparation systems used in the treatment of enthesopathies: A preliminary study
2021
Background Autologous platelet-rich plasma (PRP) injection is an alternative but widely accepted method for the treatment of degenerative changes in tendon attachments known as enthesopathies. The PRP is considered a safe source for high concentrations of the growth factors involved in the healing process. Despite initial promising outcomes, many recent studies report conflicting results for this treatment. This may be due to differences in the concentrations of platelets and growth factors in PRPs obtained using different methods. Objectives The aim of this study was to compare PRP preparation systems in terms of morphotic components and selected growth factors to find the most appropriate…
Clonidine increases membrane-associated phospholipase A2
2005
Background and objective: An anti-inflammatory effect of α 2 -adrenoreceptor agonists has been suggested. Phospholipase A 2 is a key enzyme in the production of precursors of inflammatory lipid mediators. The aim of the present study was to investigate the effect of clonidine on phospholipase A 2 activity in an established in vitro model. Methods: Human being platelet membranes containing active phospholipase A 2 were exposed to buffer control or to three increasing concentrations of clonidine. Phospholipase A 2 was measured by a radioisotope technique. Results: A massive increase in phospholipase A 2 activity was measured after clonidine exposure leading to final values of 92.5 ′ 3.1 pmol …
The mechanisms of thrombotic risk induced by hormone replacement therapy.
2001
Abstract Objective : To review the available information on the action of hormones on the mechanisms involved in thrombotic risk. Results and Conclusions : Thrombosis plays a crucial role in the genesis and progression of both coronary heart disease (CHD) and venous thromboembolic disease (VTED), the two main forms of cardiovascular disease. Two main determinants of the thromboembolic phenotype, hypercoagulable state and altered endothelium, accumulate much of the work performed on the influence of hormones on thrombosis. Information has accumulated mainly for oestrogens, but increasing evidences support a role for progestogens. The sensitivity of each of the three components of the hemosta…