Search results for "Platelet membrane glycoprotein"
showing 10 items of 16 documents
Hematologic effects of recombinant human granulocyte colony-stimulating factor in patients with malignancy.
1989
Abstract The effect of recombinant human granulocyte colony-stimulating factor (G-CSF) on hematologic parameters was evaluated in a phase I clinical study in 18 patients with advanced malignancy. G-CSF was administered once daily as a 30-minute infusion for 14 days; three patients each were treated at increasing dose levels of 1, 3, 10, 30, and 60 micrograms kg-1 day-1. A transient decrease in neutrophil and monocyte counts was observed immediately after the G-CSF infusion, followed by a dose-dependent increase of up to 15-fold. G-CSF-induced neutrophils exhibited an increased O2- radical production, and serum levels of enzymes related to granulocyte turnover, including lysozyme and elastas…
A Cytologic Assay for Diagnosis of Food Hypersensitivity in Patients With Irritable Bowel Syndrome
2010
BACKGROUND & AIMS: A percentage of patients with symptoms of irritable bowel syndrome (IBS) suffer from food hypersensitivity (FH) and improve on a food-elimination diet. No assays have satisfactory levels of sensitivity for identifying patients with FH. We evaluated the efficacy of an in vitro basophil activation assay in the diagnosis of FH in IBS-like patients. METHODS: Blood samples were collected from 120 consecutive patients diagnosed with IBS according to Rome II criteria. We analyzed in vitro activation of basophils by food allergens (based on levels of CD63 expression), as well as total and food-specific immunoglobulin (Ig)E levels in serum. Effects of elimination diets and dou…
Association between platelet glycoprotein Ib-alpha and myocardial infarction: results of a pilot study performed in male and female patients from Sic…
2007
Myocardial infarction (AMI) is a complex multifactorial disorder. Platelet adhesion and thrombosis are pivotal events in the development of atherosclerotic lesions. Occlusive thrombus is almost exclusively initiated by plaque rupture and adhesion of platelets to subendothelial von Willebrand factor (vWf) by its specific platelet receptor, the alpha-chain of glycoprotein (GP) Ib-IX-V complex of the human platelet-specific antigens (HPA). Two polymorphisms have been reported in the sequence of GPIb-alpha. The first, a C/T transition at nucleotide 1018 results in an amino acid dimorphism (Thr/Met) at residue 145 of GPIb-alpha, which is located within the vWF-binding domain of the receptor. The…
Immunolocalization of Tenascin-C in Human Type II Fiber Atrophy
2000
Tenascin-C is a multifunctional extracellular matrix glycoprotein with stimulatory and anti-adhesive or inhibitory properties for axon growth. Its location and discontinuous expression are restricted in innervated muscle tissues. Tenascin-C accumulated interstitially among human denervated muscle fibers and close to normal-sized fibers. To expand our knowledge of the expression of tenascin-C in human neuromuscular disorders, we investigated immunohistologically 20 human muscle specimens with type II myofiber atrophy of children and adults. Tenascin-C immunoreactivity in adult type II atrophy was frequent, and accumulation in children was sparse and weak. In both groups, tenascin-C immunorea…
Vitamin C blocks inflammatory platelet-activating factor mimetics created by cigarette smoking.
1997
Cigarette smoking within minutes induces leukocyte adhesion to the vascular wall and formation of intravascular leukocyte-platelet aggregates. We find this is inhibited by platelet-activating factor (PAF) receptor antagonists, and correlates with the accumulation of PAF-like mediators in the blood of cigarette smoke-exposed hamsters. These mediators were PAF-like lipids, formed by nonenzymatic oxidative modification of existing phospholipids, that were distinct from biosynthetic PAF. These PAF-like lipids induced isolated human monocytes and platelets to aggregate, which greatly increased their secretion of IL-8 and macrophage inflammatory protein-1alpha. Both events were blocked by a PAF r…
Novel α2β1 integrin inhibitors reveal that integrin binding to collagen under shear stress conditions does not require receptor preactivation.
2012
The interaction between α2β1 integrin (GPIa/IIa, VLA-2) and vascular collagen is one of the initiating events in thrombus formation. Here, we describe two structurally similar sulfonamide derivatives, BTT-3033 and BTT-3034, and show that, under static conditions, they have an almost identical effect on α2-expressing CHO cell adhesion to collagen I, but only BTT-3033 blocks platelet attachment under flow (90 dynes/cm(2)). Differential scanning fluorimetry showed that both molecules bind to the α2I domain of the recombinant α2 subunit. To further study integrin binding mechanism(s) of the two sulfonamides, we created an α2 Y285F mutant containing a substitution near the metal ion-dependent ad…
Identifying human platelet glycoproteins IIb and IIIa by capillary electrophoresis.
1998
Glanzmann thrombasthenia (GT) is an inherited hemorrhagic defect due to a failure of the platelet membrane glycoprotein (GP) IIb–IIIa complex. Capillary electrophoresis (CE) analysis of solubilized platelet membranes from normal individuals showed the presence of two peaks with a migration time of 27 and 29 min, respectively. An excellent run-to-run and day-to-day reproducibility of the technique (< 1% variation of the retention time) was documented. Using an automated Ferguson method, the apparent molecular masses were 100.0 kDa and 138.5 kDa, respectively. Immunoprecipitation with monoclonal antibodies anti-GP IIIa (B59.2.1) and anti-IIb (61.9.1.3) showed the two peaks as IIIa and IIb, re…
High-throughput elucidation of thrombus formation reveals sources of platelet function variability
2019
In combination with microspotting, whole-blood microfluidics can provide high-throughput information on multiple platelet functions in thrombus formation. Based on assessment of the inter-and intra-subject variability in parameters of microspot-based thrombus formation, we aimed to determine the platelet factors contributing to this variation. Blood samples from 94 genotyped healthy subjects were analyzed for conventional platelet phenotyping: i.e. hematologic parameters, platelet glycoprotein (GP) expression levels and activation markers (24 parameters). Furthermore, platelets were activated by ADP, CRP-XL or TRAP. Parallel samples were investigated for whole-blood thrombus formation (6 mi…
Flow Cytometric Analysis of Calcium Mobilization in Whole‐Blood Platelets
2003
Flow cytometry provides a convenient method to evaluate platelet activation by following the kinetics of intracellular free Ca2+, using sensitive fluorescent indicators that can be loaded into intact cells. Moreover, in the clinical setting, whole-blood techniques have obvious advantages to avoid artifactual platelet activation and allow the maintenance of near-physiological conditions. This unit describes a fast and sensitive flow cytometric procedure using the Ca2+-sensitive dye fluo-3 AM and the platelet-specific antibody CD41-PE to determine the kinetics of intracellular Ca2+ mobilization in whole-blood platelets with minimal manipulation of the samples. The technique may be applied to …
Allergen-induced IgE-dependent gut inflammation in a human PBMC-engrafted murine model of allergy.
2011
Background Humanized murine models comprise a new tool to analyze novel therapeutic strategies for allergic diseases of the intestine. Objective In this study we developed a human PBMC–engrafted murine model of allergen-driven gut inflammation and analyzed the underlying immunologic mechanisms. Methods Nonobese diabetic (NOD)– scid -γc −/− mice were injected intraperitoneally with human PBMCs from allergic donors together with the respective allergen or not. Three weeks later, mice were challenged with the allergen orally or rectally, and gut inflammation was monitored with a high-resolution video miniendoscopic system, as well as histologically. Results Using the aeroallergens birch or gra…