Search results for "Leukocyte"
showing 10 items of 970 documents
Phospholipase A2 and arachidonic acid: a common link in the generation of the eosinophil chemotactic factor (ECF) from human PMN by various stimuli.
1980
An eosinophil chemotactic factor (ECF) of low molecular weight can be generated and released from human polymorphonuclear neutrophils by the calcium ionophore, phagocytosis of zymosan particles, arachidonic acid, and phospholipase A2. Since the activation of cells by the ionophore and during the phagocytic event leads to phospholipid turnover, with the subsequent generation of arachidonic acid, it is reasonable that phospholipase A2 represents the common link for ECF production. The kinetics of ECF release by phospholipase A2 is similar to the pattern observed with the various stimuli. After a rapid rise in activity a decline occurred at later times of secretion, suggesting a mechanism of i…
Generation and release of eosinophil chemotactic factor from human polymorphonuclear neutrophils by arachidonic acid
1978
This study describes the generation and release of an eosinophil chemotactic factor from human polymorphonuclear neutrophils, rat basophilic leukemia cells, and from a lymphocyte monocyte basophil suspension by arachidonic acid (AA). The eosinophil chemotactic factor (ECF) is highly specific for eosinophils and resembles the ECF activity obtained from human polymorpho-nuclear neutrophils after stimulation with the Ca ionophore or during phagocytosis. In this regard, AA-induced ECF represents a biological activity distinct from oxidized AA and its conversion products. AA may therefore have a dual function: it represents an important mechanism of cell activation; as AA is converted into prost…
Characterization of neutrophil subsets in healthy human pregnancies
2014
We have previously shown that in successful pregnancies increased arginase activity is a mechanism that contributes to the suppression of the maternal immune system. We identified the main type of arginase-expressing cells as a population of activated low-density granulocytes (LDGs) in peripheral blood mononuclear cells and in term placentae. In the present study, we analyzed the phenotype of LDGs and compared it to the phenotype of normal density granulocytes (NDGs) in maternal peripheral blood, placental biopsies and cord blood. Our data reveal that only LDGs but no NDGs could be detected in placental biopsies. Phenotypically, NDGs and LDGs from both maternal and cord blood expressed diff…
Phenylpropanoid and phenylisoprenoid metabolites from Asteraceae species as inhibitors of protein carbonylation.
2011
Abstract Three phenolic antioxidant and anti-inflammatory compounds: 7-methylaromadendrin, isoprenylhydroquinone glucoside, and 3.5-dicaffeoylquinic acid methyl ester, all isolated from Western Mediterranean Asteraceae species, have been studied for their inhibitory activity against protein carbonylation, a harmful post-translational modification of peptide chains associated with degenerative diseases. All compounds have proven to be effective, with 50% inhibitory concentration (IC 50 ) values in the micromolar range, against bovine serum albumin carbonylation caused by hypochlorite, peroxynitrite, and phorbol ester-induced leukocyte oxidative burst.
Antibacterial and antioxidant activities in Sideritis italica (Miller) Greuter et Burdet essential oils
2006
Sideritis italica (Miller) Greuter et Burdet is a widespread Lamiacea in the Mediterranean region used in traditional medicine. Essential oils were antibacterial against nine ATCC and as many clinically isolated Gram-positive and Gram-negative bacterial strains. Antibacterial activity was also found against Helicobacter pylori: a dose-dependant inhibition was shown between 5 and 25 microg/ml. The antibacterial activity of the oils was expressed as MICs (minimum inhibitory concentrations) and MBCs (minimum bactericidal concentrations). At a concentration between 3.9 and 250 microg/ml the oils showed a significant antibacterial effect against both Gram-negative and Gram-positive bacteria. In …
Diterpenoids from Tetraclinis articulata that Inhibit Various Human Leukocyte Functions
2003
Ten new compounds, eight of them pimarane derivatives (1-8), together with a menthane dimer (9) and a totarane diterpenoid (10), were isolated from the leaves and wood of Tetraclinis articulata. The structures of 1-10 were established by using spectroscopic techniques, including 2D NMR spectra. Pimaranes 1-5 were found to possess an unusual cis interannular union of the B and C rings, which, from a biogenetic perspective, could be derived from the hydration of a carbocation at C-8. Compounds 4-6 and a mixture of 7 and 11 modulated different human leukocyte functions at a concentration of 10 microM, mainly the degranulation process measured as myeloperoxidase release and, to a lesser extent,…
Donor Genetic Determinant of Thymopoiesis rs2204985 Impacts Clinical Outcome after Single HLA Mismatched HSCT
2021
Abstract Introduction: A common genetic variant within the TCRA-TCRD locus has been recently identified as a predictive factor of thymic function and T cell repertoire diversity (Clave et al., 2018). Specifically it was shown in a mouse model that transplantation of rs2204985 AA human hematopoietic stem cells (HSC) into immunodeficient mice led to lower thymocyte counts and poorer TCR diversity. T cell mediated pathways are known to play a significant role in immunological processes affecting HSCT outcome like GvL, GvH and infection. Aim of this study was to investigate the potential impact of donor rs2204985 genotype on patient's outcome after unrelated HSCT. Methods: The study included 2,…
A phase I/II multicentric trial of gemcitabine and epirubicin in patients with advanced pancreatic carcinoma
2006
Potential synergistic interaction between gemcitabine (GEM) and epirubicin (EPI) in pancreatic cancer have been described previously. The maximum-tolerated dose in this trial was GEM 1000 mg m(-2) and EPI 45 mg m(-2). Median time to progression was 5.1 months and median survival time 7.4 months. This combination appears well tolerated and shows promising clinical activity.
Effect of granulocyte-macrophage colony-stimulating factor on neutropenia and related morbidity induced by myelotoxic chemotherapy.
1990
Abstract purpose: A phase Ib/II clinical study was undertaken to assess the efficacy of recombinant human (rh) granulocyte-macrophage colony-stimulating (GM-CSF) factor in attenuating neutropenia and associated morbidity caused by high-dose anticancer chemotherapy administered in the presence or absence of autologous bone marrow support. patients and methods: Twenty-two patients with various solid tumors and lymphoid neoplasias were treated with a single daily subcutaneous dose of rh GM-CSF (250/μg/m 2 ) 48 hours after receiving a second cycle of highly myelotoxic chemotherapy for a period of 10 days. Within-subject comparisons on neutropenia-related clinical and laboratory variables were m…
A polymorphism in the TYMP gene is associated with the outcome of HLA-identical sibling allogeneic stem cell transplantation.
2013
Thymidine phosphorylase (TYMP), an enzyme involved in nucleotide synthesis, has been implicated in critical biological processes such as DNA replication, protection against mutations, and tissue repair. In this work, we retrospectively evaluated the influence of a polymorphism in the TYMP gene (rs112723255; G/A) upon the outcome of 448 patients subjected to allogeneic stem cell transplantation (allo-SCT) from an human leukocyte antigen (HLA)-identical sibling donor. The TYMP genotype of patients correlated with overall survival—carriers of the minor allele (A) being at an increased risk of dying after transplantation (hazard ratio, HR = 1.9; P = 0.004). This effect was mostly due to differe…