Search results for "Leukocytes"
showing 10 items of 429 documents
Polynitroxylated hemoglobin-based oxygen carrier: inhibition of free radical-induced microcirculatory dysfunction.
1999
Reactive oxygen species have been identified as key mediators of leukocyte/endothelial cell interaction under various pathological conditions and diseases such as ischemia/reperfusion injury, inflammation, and after exposure to cigarette smoke. Consequently, antioxidants have been shown to successfully prevent the sequelae of these conditions, ranging from tissue infarction to atherogenesis. In this study we investigated whether, via its established superoxide dismutase-like activity, a novel polynitroxyl hemoglobin-based oxygen carrier (PNH), could affect the stimulation of leukocyte rolling and adhesion to endothelial cells in response to cigarette smoke. Using the dorsal skin fold chambe…
Abacavir and didanosine induce the interaction between human leukocytes and endothelial cells through Mac-1 upregulation
2010
Objective: Abacavir and didanosine are nucleoside reverse transcriptase inhibitors (NRTI) widely used in therapy for HIV-infection but which have been linked to cardiovascular complications. The objective of this study was to analyze the effects of clinically relevant doses of abacavir and didanosine on human leukocyte―endothelium interactions and to compare them with those of other NRTIs. Design and methods: The interactions between human leukocytes ― specifically peripheral blood polymorphonuclear (PMN) or mononuclear (PBMC) cells ― and human umbilical vein endothelial cells were evaluated in a flow chamber system that reproduces conditions in vivo. The expression of adhesion molecules wa…
Differential effects of anti-TNF-α and anti-IL-12/23 agents on human leukocyte–endothelial cell interactions
2015
AbstractEnhanced leukocyte recruitment is an inflammatory process that occurs during early phases of the vascular dysfunction that characterises atherosclerosis. We evaluated the impact of anti-TNF-α (adalimumab, infliximab and etanercept) and anti-IL-12/23 (ustekinumab) on interactions between human leukocytes and endothelial cells in a flow chamber that reproduced in vivo conditions. Clinical concentrations of anti-TNF-α were evaluated on the leukocyte recruitment induced by a variety of endothelial (TNF-α, interleukin-1β, lymphotoxin-α and angiotensin-II) and leukocyte (PAF, IL-12 and IL-23) stimuli related to inflammation and atherosclerosis. Treatment with anti-TNF-α, even before or af…
Characterization of a novel population of low-density granulocytes associated with disease severity in HIV-1 infection
2012
The mechanisms resulting in progressive immune dysfunction during the chronic phase of HIV infection are not fully understood. We have previously shown that arginase, an enzyme with potent immunosuppressive properties, is increased in HIV seropositive (HIV+) patients with low CD4(+) T cell counts. Here we show that the cells expressing arginase in peripheral blood mononuclear cells of HIV+ patients are low-density granulocytes (LDGs) and that whereas these cells have a similar morphology to normal-density granulocyte, they are phenotypically different. Importantly, our results reveal that increased frequencies of LDGs correlate with disease severity in HIV+ patients.
Cell-mediated lipoprotein transport: A novel anti-atherogenic concept
2010
Lipoprotein transport is thought to occur in the plasma compartment of the blood, where lipoproteins are modulated by various enzymatic reactions. Subsequently, lipoproteins can migrate through the endothelial barrier to the subendothelial space or are taken up by the liver. The interaction between pro-atherogenic (apoB-containing) lipoproteins and blood cells (especially monocytes and macrophages) in the subendothelial space is well known. This lipoprotein-inflammatory cell interplay is central in the development of the atherosclerotic plaque. In this review, a novel interaction is described between lipoproteins and both leukocytes and erythrocytes in the blood compartment. This lipoprotei…
Anti-HIV-1 activity of inorganic polyphosphates.
1997
Human blood plasma, serum, peripheral blood mononuclear cells, and erythrocytes contain significant amounts of inorganic polyphosphates (ranging from 53 to 116 microM, in terms of phosphate residues). Here we demonstrate that at higher concentrations linear polyphosphates display cytoprotective and antiviral activity. Sodium tetrapolyphosphate and the longer polymers, with average chain lengths of 15, 34, and 91 phosphate residues, significantly inhibited human immunodeficiency virus type 1 (HIV-1) infection of cells in vitro at concentrations > or = 33.3 microg/ml (> or = 283-324 microM phosphate residues), whereas sodium tripolyphosphate was ineffective. In the tested concentration range,…
AN IL-6/IL-6 SOLUBLE RECEPTOR (IL-6R) HYBRID PROTEIN (H-IL-6) INDUCES EPO-INDEPENDENT ERYTHROID DIFFERENTIATION IN HUMAN CD34+CELLS
2000
H-IL-6 is a hybrid protein constructed to contain IL-6 and its soluble receptor linked by a flexible peptide chain. Here we show that H-IL-6 strongly enhances proliferation of human CD34(+)cells in serum-free liquid culture, and that the majority of the cells generated belong to the erythroid lineage, being positive for the marker Glycophorin A. Conversely, H-IL-6 does not increase the number of myeloid, CD13-positive cells. Comparable effects are observed on progenitors from cord blood and adult peripheral blood. Therefore, H-IL-6 triggers an erythroid-inducing signal in haematopoietic progenitor cells, independently from erythropoietin (EPO).
Correlation between HHV-6 reactivation and multiple sclerosis disease activity.
2002
This study examined the association between HHV-6 infection and multiple sclerosis (MS) and the relationship between HHV-6 reactivation and disease activity. The frequency of HHV-6 genomic sequences in peripheral blood mononuclear cells (PBMCs), the incidence of plasma viremia (nPCR), the transcription of viral mRNA in PBMCs (RT-PCR), the presence of antiviral IgM and IgG class antibodies in the plasma (IFA) of 16 relapsing/remitting and secondary progressive MS patients were studied in comparison with clinical manifestations of the disease, magnetic resonance imaging (MRI) of brain, and serum interleukin (IL)-12 concentrations (ELISA). The prevalence of HHV-6 infection was significantly hi…
Beneficial Effect of Shikonin on Experimental Colitis Induced by Dextran Sulfate Sodium in Balb/C Mice
2012
[EN] The naphthoquinone shikonin, a major component of the root of Lithospermum erythrorhizon, now is studied as an anti-inflammatory agent in the treatment of ulcerative colitis (UC). Acute UC was induced in Balb/C mice by oral administration of 5% dextran sodium sulfate (DSS). The disease activity index was evaluated, and a histologic study was carried out. Orally administered shikonin reduces induced UC in a dose-dependent manner, preventing the shortening of the colorectum and decreasing weight loss by 5% while improving the appearance of feces and preventing bloody stools. The disease activity index score was much lower in shikonin-treated mice than in the colitic group, as well as the…
The Length of Leukocyte and Femoral Artery Telomeres in Patients with Peripheral Atherosclerosis.
2022
The length of telomeres (TLs) that protect chromosome ends may reflect the age of cells as well as the degree of genetic material damage caused by external factors. Since leukocyte telomere length is associated with cardiovascular diseases, the aim of this study was to evaluate whether leukocyte TL reflects femoral artery wall telomeres of patients with atherosclerosis and lower limb ischemia. Samples of femoral artery wall and blood were collected from 32 patients qualified to surgical revascularization. The analysis included blood and artery wall telomere length measurement and biochemical parameters. The study indicated that there was a moderate correlation between artery wall TL and leu…