Search results for "activation"

Nitric Oxide Production and Arachidonic Acid Metabolism in Platelet Membranes of Coronary Heart Disease Patients with and without Diabetes

2001

<i>Aim:</i> To evaluate the levels of nitrite (NO<sup>–</sup><sub>2</sub>) and nitrate (NO<sup>–</sup><sub>3</sub>) ions and the incorporation of [<sup>3</sup>H]arachidonic acid (AA) into phospholipids of platelet membranes from coronary artery disease (CAD) patients with and without diabetes (NIDDM). <i>Subjects and Methods:</i> Eighteen CAD patients (group A), 18 CAD patients with NIDDM (group B), and 20 healthy controls (group C) without dyslipidemia, peripheral vascular disease and hypertension were included in the study. The groups were matched for age, sex and body mass index. The diagnosis of CAD was …

Newly diagnosed depression is associated with increased beta-thromboglobulin levels and increased expression of platelet activation markers and plate…

2013

Abstract Background Inflammation plays a key role in atherosclerotic disease. Up until now only limited evidence exists on the mechanism of cardiovascular complications in patients with depression. In addition depression was also linked to an increase in cardiovascular mortality. The present study was designed to evaluate the extent of platelet activation and platelet-derived markers of atherosclerotic disease in patients with newly diagnosed depression. Methods This study used whole blood aggregometry, flow cytometry and ELISA to investigate platelet CD62P (P-selectin) expression and atherosclerotic markers (CD40, CD40L) as well as serum platelet factor 4 (PF-4) and beta-thromboglobulin (β…

Spontaneous echo contrast caused by platelet and leukocyte aggregates?

2001

Background and Purpose —Spontaneous echocardiographic contrast (SEC) is correlated to clinical thromboembolic events. We sought to determine the origin of SEC by utilizing direct analysis of left atrial blood. Methods —We examined the blood of 13 patients with and 19 without SEC. Blood samples were taken from the femoral vein and artery and from the right and left atria after transseptal puncture. Samples were incubated with fluorescence-labeled antibodies directed against the platelet (CD41a-PE, CD42b-PE, and CD62p-FITC) and leukocyte membrane epitopes (CD45-APC and CD14-FITC). The expressed epitopes were analyzed by dual laser flow cytometry immediately after blood withdrawal. Results —I…

Increased thromboxane biosynthesis in type IIa hypercholesterolemia.

1992

BACKGROUND Increased platelet thromboxane (TX)A2 production has been described in type IIa hypercholesterolemia. To verify the relevance of these capacity-related measurements to the actual rate of TXA2 biosynthesis in vivo, we studied the urinary excretion of its major enzymatic metabolites in 46 patients with type IIa hypercholesterolemia and 20 age-matched controls. METHODS AND RESULTS Urinary 11-dehydro-TXB2 and 2,3-dinor-TXB2 were measured by previously validated radioimmunoassays. The excretion rate of 11-dehydro-TXB2 was significantly (p less than 0.001) higher in patients (68.7 +/- 35.1 ng/hr, mean +/- SD) than in controls (22.4 +/- 9.4 ng/hr), with metabolite excretion greater tha…

Effect of training status on the changes in platelet parameters induced by short–duration exhaustive exercise

2015

It is now well known that hemostasis is directly involved in the benefits induced by physical activity. It has recently been shown that the baseline mean platelet volume (MPV) may be a predictor of endurance performance. We aimed to explore whether platelet parameters are associated with VO2max as well as running duration and speed in a short-duration exhaustive exercise test. Thirty healthy male subjects (10 sedentary and 20 trained) performed an incremental running test until exhaustion. MPV, platelet distribution width (PDW), platelet (Plt) count, and plateletcrit (Pct) were determined before exercise, immediately after exercise and after 30′ recovery. Training status did not produce any…

Association between physical fitness and mean platelet volume in professional soccer players.

2014

Reconstitution of CMV pp65 and IE-1-specific IFN-γ CD8+ and CD4+ T-cell responses affording protection from CMV DNAemia following allogeneic hematopo…

2011

Threshold levels of CMV-specific T-cell populations presumably affording protection from active CMV infection in allo-SCT recipients have been proposed, but lack extensive validation. We quantified CMV pp65 and immediate-early 1-specific IFN-γ CD8(+) and CD4(+) T cell responses at days +30, +60 and +90 after transplantation in 133 patients, and established cutoff cell levels protecting from CMV DNAemia within the first 120 days after transplantation. No patients showing IFN-γ CD8(+) or IFN-γ CD4(+) T-cell counts1.0 and1.2 cells/μL, respectively, developed a subsequent episode of CMV DNAemia. Initial or recurrent episodes of CMV DNAemia occurred in the face of IFN-γ T-cell levels below defin…

Autoreactive CD4+ LKM-specific and anticlonotypic T-cell responses in LKM-1 antibody-positive autoimmune hepatitis

1996

Peripheral blood mononuclear cells (PBMC) of patients with autoimmune hepatitis (AIH) and controls were studied for their proliferative response to six overlapping synthetic peptides covering the 33-amino acid immunodominant region of cytochrome P450IID6, the main target antigen of LKM-1 antibody-positive type II AIH. PBMC from 8 of 8 type II AIH patients (100%), 6 of 12 LKM-1 antibody-negative type I AIH patients (50%), but only 4 of 31 patients with chronic hepatitis C (12.9%) reacted with a 23-amino acid LKM peptide and mainly with a shorter 18-amino acid LKM peptide. Follow-up showed that LKM-specific T-cell responses decreased after immunosuppression had started. Fine specificity, HLA …

Reversible effect of magnetic fields on human lymphocyte activation patterns: different sensitivity of naive and memory lymphocyte subsets.

2009

The aim of this study was to investigate the influence of 50 Hz magnetic or static magnetic fields of 0.5 mT on subsets of human CD4(+) T cells in terms of cytokine release/content, cell proliferation and intracellular free calcium concentration. CD4(+) T cells can be divided into different subsets on the basis of surface marker expression, such as CD45, and T cells can be divided into naive (CD45RA(+)) and memory (CD45RA(-)) cells. In this study, the effects of magnetic fields after 24 and 48 h of cell culture were analyzed. We found that the CD4(+)CD45RA(-) T subset were more sensitive after 2 h of exposure. Decreases in the release/content of IFN-gamma, in cell proliferation and in intra…

CD28-dependent Rac1 activation is the molecular target of azathioprine in primary human CD4+ T lymphocytes

2003

Azathioprine and its metabolite 6-mercaptopurine (6-MP) are immunosuppressive drugs that are used in organ transplantation and autoimmune and chronic inflammatory diseases such as Crohn disease. However, their molecular mechanism of action is unknown. In the present study, we have identified a unique and unexpected role for azathioprine and its metabolites in the control of T cell apoptosis by modulation of Rac1 activation upon CD28 costimulation. We found that azathioprine and its metabolites induced apoptosis of T cells from patients with Crohn disease and control patients. Apoptosis induction required costimulation with CD28 and was mediated by specific block- ade of Rac1 activation thro…