Search results for "Blood Platelets"
showing 10 items of 168 documents
Membrane fluidity, membrane lipid pattern, and cytosolic Ca2+ content in platelets from a group of type II diabetic patients with macrovascular compl…
1995
OBJECTIVE To evaluate platelet membrane fluidity and some platelet metabolic parameters in type II diabetic patients with macrovascular complications. RESEARCH DESIGN AND METHODS In a group of 21 type II diabetic patients with macrovascular complications, we evaluated platelet membrane fluidity [marking intact resting platelets with the fluorescent probe 1,4-(trimethylamino)-phenyl-4-phenylhexatriene (TMA-DPH)], platelet membrane lipid pattern (cholesterol :phospholipid [C:PL] ratio and individual phospholipids), and platelet cytosolic Ca2+ content (marking intact resting platelets with the fluorescent probe Fura 2AM). RESULTS Platelet membrane fluidity is decreased in type II diabetic pat…
Circulating immune complexes and platelet thromboxane synthesis in patients with insulin-dependent (type I) diabetes mellitus
1984
Platelets from diabetic subjects with circulating immune complexes (CIC) synthesized greater amounts of thromboxane than did platelets from CIC-negative patients or controls. In view of the known action of CIC on platelet function, a relationship between these two factors may be suggested in the initiation and progression of microangiopathy in diabetes.
A single loading dose of clopidogrel causes dose-dependent improvement of endothelial dysfunction in patients with stable coronary artery disease: Re…
2006
Clinical studies have demonstrated beneficial effects for clopidogrel in patients with atherothrombotic disease. Recent in vitro studies identified stimulating effects of clopidogrel on endothelial cells, pointing towards mechanisms of action beyond the inhibition of platelet aggregation. We hypothesized that in vivo use of clopidogrel improves endothelial dysfunction in patients with coronary artery disease (CAD). Fifty-eight patients with CAD were randomly assigned to double-blinded oral administration of one single dose of clopidogrel 300 mg (C300) or 600 mg (C600), respectively. Endothelial function was assessed by measurement of flow-mediated dilation (FMD) of the brachial artery befor…
Buffy coat-derived platelets cryopreserved using a new method: Results from a pivotal clinical trial on thrombocytopenic patients with acute leukaemia
2019
Abstract The administration of cryopreserved platelets (PLTs) may overcome the limits of platelet shortage and availability, especially during some seasons or in specific contexts like rural areas. After in vitro validation studies, ad hoc prepared buffy coat-derived pooled platelet concentrates (BC-PLTs), treated with dimethyl sulphoxide (DMSO) and cryopreserved (CRY BC-PLTs) at -80 °C with a modified Valeri method, were transfused in patients with severe thrombocytopenia secondary to chemotherapy for acute leukaemia (AL). Five inpatients were enrolled in the pivotal clinical trial NCT02032134: 4 males and 1 female with a mean age of 71 years (range: 65–80). Four patients were diagnosed wi…
Connectivity percolation in suspensions of hard platelets
2012
We present a study on connectivity percolation in suspensions of hard platelets by means of Monte Carlo simulation. We interpret our results using a contact-volume argument based on an effective single--particle cell model. It is commonly assumed that the percolation threshold of anisotropic objects scales as their inverse aspect ratio. While this rule has been shown to hold for rod-like particles, we find that for hard plate-like particles the percolation threshold is non-monotonic in the aspect ratio. It exhibits a shallow minimum at intermediate aspect ratios and then saturates to a constant value. This effect is caused by the isotropic-nematic transition pre-empting the percolation tran…
Non-steroidal Anti-inflammatory Agents, Part 19:E-2-Pyrrolizin-5-yl Acrylic Acids as Potent Dual or Selective Inhibitors of Bovine Cyclooxygenase and…
1995
The pyrrolizinyl substituted acrylic acid derivatives represent another class of dual and selective inhibitors of cyclooxygenase and 5-lipoxygenase. By modifying their substitution pattern at the phenyl moiety of C-6 the balance between the activity against cyclooxygenase and against 5-lipoxygenase can be shifted. Structure-activity relationships are discussed. Compound 6k is the most potent and well-balanced dual inhibitor of both enzymes, while the highest selectivity of lipoxygenase inhibition was found for 6j. The activity and selectivity of compounds with an additional sulfur moiety depend on the oxidation status of this atom, giving an indication of the discussed coupling between pero…
Inhibition of inflammatory responses by epitaondiol and other marine natural products
1995
The marine metabolites pacifenol, stypotriol triacetate and epitaondiol were tested for their effects on a number of inflammatory responses. Epitaondiol exhibited a potent topical anti-inflammatory activity related to inhibition of leukocyte accumulation. The other compounds showed a lower potency, similar to that of indomethacin. None of the compounds affected superoxide generation by human neutrophils but pacifenol effectively inhibited the degranulation response. This compound and epitaondiol decreased the release of eicosanoids with a higher potency on the cyclo-oxygenase pathway. Only epitaondiol inhibited human recombinant synovial phospholipase A2 activity in a concentration-dependen…
Activation of cGMP-dependent Protein Kinase Iβ Inhibits Interleukin 2 Release and Proliferation of T Cell Receptor-stimulated Human Peripheral T Cells
2000
Several major functions of type I cGMP-dependent protein kinase (cGK I) have been established in smooth muscle cells, platelets, endothelial cells, and cardiac myocytes. Here we demonstrate that cGK Ibeta is endogenously expressed in freshly purified human peripheral blood T lymphocytes and inhibits their proliferation and interleukin 2 release. Incubation of human T cells with the NO donor, sodium nitroprusside, or the membrane-permeant cGMP analogs PET-cGMP and 8-pCPT-cGMP, activated cGK I and produced (i) a distinct pattern of phosphorylation of vasodilator-stimulated phosphoprotein, (ii) stimulation of the mitogen-activated protein kinases ERK1/2 and p38 kinase, and, upon anti-CD3 stimu…
A peptide from the staphylococcal protein Efb binds P‐selectin and inhibits the interaction of platelets with leukocytes
2022
AimsP-selectin is a key surface adhesion molecule for the interaction of platelets with leukocytes. We have shown previously that the N-terminal domain of S. aureus extracellular fibrinogen-binding protein (Efb) binds to P-selectin and interferes with platelet-leukocyte aggregate formation. Here, we aimed to identify the minimal Efb motif required for binding platelets and to characterise its ability to interfering with the formation of platelet-leukocyte aggregates.Methods and ResultsUsing a library of synthetic peptides, we mapped the platelet-binding site to a continuous 20 amino acid stretch. The peptide Efb68-87 was able to bind to resting and, to a greater extent, thrombin-stimulated …
Influence of traditional Chinese anti-inflammatory medicinal plants on leukocyte and platelet functions.
2003
Abstract The enzymes 5-lipoxygenase and elastase are therapeutic targets in dermatological disorders such as psoriasis. Fifteen extracts from traditional Chinese medicinal plants used to treat topical inflammations were screened for their inhibitory effect on lipoxygenase, cyclooxygenase and elastase activity in intact leukocytes and platelets. Astragalus membranaceus, Forsythia suspensa and Poria cocos inhibited 5-lipoxygenase, with IC50 values of 141, 80 and 141 μg mL−1, respectively. The latter two species, along with Angelica dahurica and Angelica pubescens, also inhibited elastase (IC50 values of 80, 123, 68 and 93 μg mL−1, respectively), while A. pubescens, Atractylodes macrocephala, …