Search results for "erythrocyte"
showing 10 items of 370 documents
Effects of the flavonol quercetin and α-linolenic acid on n-3 PUFA status in metabolically healthy men and women: a randomised, double-blinded, place…
2017
AbstractIncreased dietary intake and tissue status of the long-chainn-3 PUFA, EPA and DHA, is associated with cardiovascular benefits. Epidemiological and animal studies suggest that concomitant nutritive intake of flavonoids may increase the conversion ofα-linolenic acid (ALA) to longer-chainn-3 fatty acids EPA and DHA. We investigated the effects of increased ALA intake on fatty acid composition of serum phospholipids and erythrocytes in metabolically healthy men and women and whether fatty acid profiles and ALA conversion were affected by regular quercetin intake or sex. Subjects (n74) were randomised to receive at least 3·3 g/d ALA with either 190 mg/d quercetin (ALA+quercetin) or place…
Effect of cadmium on anion exchange capability through Band 3 protein in human erythrocytes
2018
The efficiency of transport through Band 3 protein, mediating HCO3–/Cl– exchange across erythrocytes membrane, is reduced by oxidative stress. The aim of the present study was to verify whether Band 3 protein transport efficiency is compromised by treatment with Cadmium (Cd2+), an extremely toxic heavy metal known to interfere with antioxidant enzymes, energy metabolism, gene expression and cell membranes. To this end, the rate constant for SO4= uptake through Band 3 protein (accounting for velocity of anion exchange) was measured along with membrane –SH groups, Malonyldialdehyde (MDA) and Band 3 protein expression levels in Cd2+-treated human erythrocytes (300 μM, 1 mM). Our results show t…
Monitoring of rheologic variables during postoperative high-dose brachytherapy for uterine cancer.
2004
Oxygenation of tumor tissue has recently been assed an important prerequisite for the effectiveness of radiotherapy in cervical cancer. Hyperviscosity is a common phenomenon in malignancy and a cause of reduced oxygen transport capacity that would favour tissue hypoxia. Hemorheological variables were serially tested preoperatively, during four cycles of fractionated adjuvant IR192 HDR after loading radiation (HDR-AL) of the vaginal vault (weekly intervals), and 6 months postoperatively in patients with cervical (n=12) and endometrial cancer (n=26). Women who were scheduled for benign tumor surgery served as controls (n=29). Preoperatively, in cervical and endometrial cancer patients, mean …
Biosynthesis of heme O in intraerythrocytic stages of Plasmodium falciparum and potential inhibitors of this pathway
2019
A number of antimalarial drugs interfere with the electron transport chain and heme-related reactions; however, the biosynthesis of heme derivatives in Plasmodium parasites has not been fully elucidated. Here, we characterized the steps that lead to the farnesylation of heme. After the identification of a gene encoding heme O synthase, we identified heme O synthesis in blood stage parasites through the incorporation of radioactive precursors. The presence of heme O synthesis in intraerythrocytic stages of Plasmodium falciparum was confirmed by mass spectrometry. Inabenfide and uniconazole–P appeared to interfere in heme synthesis, accordingly, parasite growth was also affected by the additi…
7-Keto-Cholesterol and Cholestan-3beta, 5alpha, 6beta-Triol Induce Eryptosis through Distinct Pathways Leading to NADPH Oxidase and Nitric Oxide Synt…
2019
Background/aims We showed that patho-physiological concentrations of either 7-keto-cholesterol (7-KC), or cholestane-3beta, 5alpha, 6beta-triol (TRIOL) caused the eryptotic death of human red blood cells (RBC), strictly dependent on the early production of reactive oxygen species (ROS). The goal of the current study was to assess the contribution of the erythrocyte ROS-generating enzymes, NADPH oxidase (RBC-NOX), nitric oxide synthase (RBC-NOS) and xanthine oxido-reductase (XOR) to the oxysterol-dependent eryptosis and pertinent activation pathways. Methods Phosphatidylserine exposure at the cell surface was estimated from annexin-V-binding, reactive oxygen/nitrogen species (RONS) and nitri…
Population snapshots predict early haematopoietic and erythroid hierarchies
2016
The formation of red blood cells begins with the differentiation of multipotent haematopoietic progenitors. Reconstructing the steps of this differentiation represents a general challenge in stem-cell biology. Here we used single-cell transcriptomics, fate assays and a theory that allows the prediction of cell fates from population snapshots to demonstrate that mouse haematopoietic progenitors differentiate through a continuous, hierarchical structure into seven blood lineages. We uncovered coupling between the erythroid and the basophil or mast cell fates, a global haematopoietic response to erythroid stress and novel growth factor receptors that regulate erythropoiesis. We defined a flow …
Comparison of hemolytic activity of the intermediate subunit of Entamoeba histolytica and Entamoeba dispar lectins.
2017
Galactose and N-acetyl-D-galactosamine-inhibitable lectin of Entamoeba histolytica has roles in pathogenicity and induction of protective immunity in rodent models of amoebiasis. Recently, the intermediate subunit of the lectin, Igl1, of E. histolytica has been shown to have hemolytic activity. However, the corresponding lectin is also expressed in a non-virulent species, Entamoeba dispar, and another subunit, Igl2, is expressed in the protozoa. Therefore, in this study, we compared the activities of Igl1 and Igl2 subunits from E. histolytica and E. dispar using various regions of recombinant Igl proteins expressed in Escherichia coli. The recombinant E. dispar Igl proteins had comparable h…
Immunological properties of oxygen-transport proteins: hemoglobin, hemocyanin and hemerythrin
2016
It is now well documented that peptides with enhanced or alternative functionality (termed cryptides) can be liberated from larger, and sometimes inactive, proteins. A primary example of this phenomenon is the oxygen-transport protein hemoglobin. Aside from respiration, hemoglobin and hemoglobin-derived peptides have been associated with immune modulation, hematopoiesis, signal transduction and microbicidal activities in metazoans. Likewise, the functional equivalents to hemoglobin in invertebrates, namely hemocyanin and hemerythrin, act as potent immune effectors under certain physiological conditions. The purpose of this review is to evaluate the true extent of oxygen-transport protein dy…
Effects of Plant Sterols or β-Cryptoxanthin at Physiological Serum Concentrations on Suicidal Erythrocyte Death.
2018
The eryptotic and hemolytic effects of a phytosterol (PS) mixture (β-sitosterol, campesterol, stigmasterol) or β-cryptoxanthin (β-Cx) at physiological serum concentration and their effect against oxidative stress induced by tert-butylhydroperoxide (tBOOH) (75 and 300 μM) were evaluated. β-Cryptoxanthin produced an increase in eryptotic cells, cell volume, hemolysis, and glutathione depletion (GSH) without ROS overproduction and intracellular Ca2+influx. Co-incubation of both bioactive compounds protected against β-Cx-induced eryptosis. Under tBOOH stress, PS prevented eryptosis, reducing Ca2+influx, ROS overproduction and GSH depletion at 75 μM, and hemolysis at both tBOOH concentrations. β…
Cytotoxic activity of Holothuria tubulosa (Echinodermata) coelomocytes.
2017
Abstract The immune system of marine invertebrates, in particular that of holothurians, still requires further study. Our research showed that coelomocyte cells contained in the coelomic fluid of the sea cucumber, Holothuria tubulosa, are able to lyse, in vitro, red blood cells in rabbits and sheep. A plaque-forming assay showed spherule cells to be the effector cells, able to release cytotoxic molecules after xenogenic cell contact. The coelomocyte lysate supernatant, analysed by polyacrylamide gel electrophoresis overlay technique, using rabbit and sheep erythrocytes, showed two different haemolytic protein patterns: one calcium dependent and the other calcium independent. The fractions o…