Search results for "erythrocytes"
showing 10 items of 218 documents
Rapid and Standardized Quantitation of Hemolytic Activity of the Fourth Component of Human Complement
1990
Based on a method that uses the fourth component of complement (C4)-deficient guinea pig serum to quantify the hemolytic activity of C4, we developed an assay that allows the processing of a large number of individual samples with high reproducibility. In contrast to the conventional procedure using titration curves of each sample to be determined, we can show that a single appropriate dilution of the sample allows accurate quantitation of hemolytic activity. The reliability of the procedure is demonstrated using either C4A- or C4B- deficient and normal individual samples.
Comparative study of biological properties and electrophoretic characteristics of lipopolysaccharide from eel-virulent and eel-A virulent Vibrio vuln…
1999
ABSTRACT In Vibrio vulnificus , virulence for eels is associated with serovar E strains. In this study, we investigated some biological properties of purified lipopolysaccharides (LPSs) from serovar E and non-serovar E strains. Purified LPSs retained their O-polysaccharidic side chains and did not show any differences that could be related to host specificity, except for serological differences.
Purification, isolation and characterization of a phosphoglycolate phosphatase isoenzyme from human erythrocytes.
1982
1. Preparation, purification and characterization of a phosphoglycolate phosphatase (PGP) isoenzyme from human erythrocytes was achieved by DEAE-Sepharose CL-6B chromatography and isoelectric focusing using carrier ampholytes, pH 4-6. 2. The isoenzyme has an isoelectric point of 5.00 +/- 0.05 and could be purified 33,000 fold to a specific activity of 32.7 U/mg of protein. It represents the PGP phenotype 1 consisting of a single isoenzyme. 3. The enzyme is composed of two subunits (mol. wt 35,000) which are identical and not connected by SS-bridges. 4. At 4 degrees C the isoenzyme is more stable in the pH range of 7-9 than at acid pH values. 5. Incubation at 30 and 40 degrees C for 4 hr doe…
N-3 fatty acids modulate antioxidant status in diabetic rats and their macrosomic offspring.
2006
We investigated the role of dietary n-3 polyunsaturated fatty acids (n-3 PUFA) in the modulation of total antioxidant status in streptozotocin (STZ)-induced diabetic rats and their macrosomic offspring. Female wistar rats, fed on control diet or n-3 PUFA diet, were rendered diabetic by administration of five mild doses of STZ on day 5 and were killed on days 12 and 21 of gestation. The macrosomic (MAC) pups were killed at the age of 60 and 90 days. Lipid peroxidation was measured as the concentrations of plasma thiobarbituric acid reactive substances (TBARS), and the total antioxidant status was determined by measuring (i) plasma oxygen radical absorbance capacity (ORAC), (ii) plasma vitami…
α-Tocopherol Modulates Phosphatidylserine Externalization in Erythrocytes
2006
Objective— The aim of the present study was to assess the effect of α-tocopherol, the main vitamin E isomer on phosphatidylserine (PS) exposure at the surface of circulating erythrocytes, and to determine consequences on erythrocyte properties. Methods and Results— In vitro α-tocopherol enrichment of isolated erythrocytes significantly decreased PS externalization as assessed by lower Annexin V-fluorescein isothiocyanate labeling. Plasma phospholipid transfer protein (PLTP) transfers vitamin E, and both α-and γ-tocopherol accumulated in circulating erythrocytes from PLTP-deficient homozygous (PLTP −/− ) mice as compared with wild-type mice. In agreement with in vitro studies, vitamin E–enr…
Description of a Simple, Specific, and Sensitive Test for the Detection of Detergent-Solubilized C3b Receptor
1981
Abstract The C3b receptor was isolated from detergent-solubilized human erythrocyte membranes by a previously described technique (1). The receptor glycoprotein was shown to enhance EAC14oxy23b rosette formation with Raji lymphoblastoid cells. This provided a specific and sensitive test to detect the solubilized C3b receptor either in crude or highly purified form. The property of the C3b receptor tested by this assay appears to be analogous to properties of β1H.
Cytoprotective effects of the antioxidant phytochemical indicaxanthin in beta-thalassemia red blood cells
2006
Antioxidant phytochemicals are investigated as novel treatments for supportive therapy in beta-thalassemia. The dietary indicaxanthin was assessed for its protective effects on human beta-thalassemic RBCs submitted in vitro to oxidative haemolysis by cumene hydroperoxide. Indicaxanthin at 1.0-10 microM enhanced the resistance to haemolysis dose-dependently. In addition, it prevented lipid and haemoglobin (Hb) oxidation, and retarded vitamin E and GSH depletion. After ex vivo spiking of blood from thalassemia patients with indicaxanthin, the phytochemical was recovered in the soluble cell compartment of the RBCs. A spectrophotometric study showed that indicaxanthin can reduce perferryl-Hb ge…
Increased susceptibility of microcytic red blood cells to in vitro oxidative stress.
1995
Oxidative damage to erythrocytes in thalassaemia has been related to generation of free radicals by an excess of denaturated alpha- or beta-globin chains, intracellular iron overload and low concentration of normal haemoglobin (HGB). Two good indicators of such oxidative damage are the high red blood cell (RBC) malonyldialdehyde (MDA) production detected following exogenous oxidant stress and the decrease of pyrimidine 5'-nucleotidase (P5N), the most sensitive enzyme to SH-group damage in vivo. Conflicting data, however, have so far accumulated in the literature concerning differences in oxidative damage between the different forms of thalassaemia and iron deficiency anaemia (IDA). In the p…
PLASMA MEMBRANE REDOX SYSTEM IN THE ERYTHROCYTES OF ROWERS: PILOT STUDY
2015
Background: The oxidative stress results from a change in the physiological balance between oxidant and antioxidant species. The purpose of this study is twofold: first, to investigate the effects of long-term training in sports with high energy requirements on the redox balance which exists between the plasma vs. the erythrocytes; second, to study the activity of the PMRS (Plasma Membrane Redox System), which is a compensatory mechanism of cellular redox homeostasis, in the rowers’ erythrocytes in order to determine the rowers’ counteraction to oxidative stress. Methods: Venous blood samples was collected from rowers and control group; then FRAP (Ferric Reducing Activity Power) method has …
Blood Transfusion Management for Patients Treated With Anti-CD38 Monoclonal Antibodies
2018
Daratumumab has proven to be highly efficacious for relapsed and refractory multiple myeloma (MM) and has recently been approved in the frontline setting for MM patients ineligible for transplantation. In the future, expanded indications are possible for daratumumab and other anti-CD38 monoclonal antibodies in development. For several years, it has been recognized that these therapies interfere with blood bank testing by binding to CD38 on red blood cells and causing panagglutination on the Indirect Antiglobulin Test. This can lead to redundant testing and significant delays in patient care. Given the anticipated increase in utilization of anti-CD38 monoclonal antibodies, as well as the tra…