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PubMed1999

No quantitative relationship between CR1 and Lutheran expression on erythrocytes: In(Lu) gene product is not a common regulator of CR1 expression on erythrocytes.

The density of CR1, the C3b/C4b receptor (CD35), on erythrocytes (E) (CR1/E) is genetically determined. However, the broad distribution of CR1/E within a given genotype suggests that other genetic elements might contribute to the regulation of CR1/E. In some pathological conditions, including systemic lupus erythematosus (SLE), AIDS and hemolytic anemia, CR1 deficiency parallels the severity of the disease. When compared to healthy individuals, an accelerated decrease in CR1/E in these patients has been demonstrated, but other mechanisms interfering with CR1 density regulation during erythropoiesis might also contribute. In exceptional circumstances, CR1/E can be dramatically decreased in healthy individuals by the effect of a regulatory gene, In(Lu), that switches off various surface molecules on E, the structure genes of which are located on four different chromosomes, suggesting a transcription regulatory role for In(Lu) gene products. The hypothesis that products of this gene could physiologically regulate the surface density of all these molecules has been tested by determining Lub density on E (Lub/E) using quantitative flow cytometry. Lub antigenic sites were then compared to CR1/E among healthy individuals of the different CR1 density phenotypes, SLE patients with and without CR1 deficiency, and an exceptional SLE patient totally lacking CR1/E and reticulocytes. No quantitative relationship was found between CR1 and Lub expression in either normal or pathological conditions. These data establish that In(Lu) products are not involved in normal or pathological CR1 density regulation.

Antibodies, Monoclonal↗
PubMed1986

Erythrocytes from cigarette smokers contain more glutathione and catalase and protect endothelial cells from hydrogen peroxide better than do erythrocytes from nonsmokers.

Recent observations regarding the ability of intracellular erythrocyte (RBC) antioxidants to decrease O2 metabolite-mediated injury to lung tissues has prompted interest in the RBC antioxidants of patients with lung disease. We found that RBC from 14 healthy, age- and gender-matched cigarette smokers contained more (p less than 0.05) glutathione (6.3 +/- 0.4 microM/g Hgb versus 5.0 +/- 0.3 microM/g Hgb) and catalase (249,533 +/- 8,307 units/g Hgb versus 222,617 +/- 7,180 units/g Hgb) than did RBC from nonsmokers. In contrast, RBC from cigarette smokers and nonsmokers contained the same activities of glutathione peroxidase (21.4 +/- 1.2 units/g Hgb versus 20.4 +/- 5.5 units/g Hgb). RBC from cigarette smokers also protected bovine pulmonary artery endothelial cells in culture from hydrogen peroxide (H2O2) better (p less than 0.005) than did RBC from nonsmokers (52.1 +/- 6.1% protection versus 31.9 +/- 5.7% protection). The results suggest that alterations in RBC antioxidants may reflect exposure and/or affect susceptibility to oxidant-induced injury.

Animals↗
PubMed1989

The erythrocyte as instigator of inflammation. Generation of amidated C3 by erythrocyte adenosine deaminase.

Myocardial ischemia is characterized by the liberation of adenosine and by complement-mediated inflammation. We have reported that amidated C3, formed when ammonia (NH3) disrupts the thiolester bond of C3, serves as an alternative pathway convertase, generates C5b-9, and stimulates phagocytic oxidative metabolism. We investigated whether the deamination of adenosine by adenosine deaminase in hematopoietic cells might liberate sufficient ammonia to form amidated C3 and thereby trigger complement-mediated inflammation at ischemic sites. In the presence of 4 mM adenosine, NH3 production per erythrocyte (RBC) was equal to that per neutrophil (PMN) (3.3 X 10(-15) mol/cell per h). Because RBC outnumber PMN in normal blood by a thousandfold, RBC are the major source of NH3 production in the presence of adenosine. NH3 production derived only from the deamination of adenosine by the enzyme adenosine deaminase and was abolished by 0.4 microM 2'-deoxycoformycin, a specific inhibitor of adenosine deaminase. When purified human C3 was incubated with 5 X 10(8) human RBC in the presence of adenosine, disruption of the C3 thiolester increased more than twofold over that measured in C3 incubated with buffer, or in C3 incubated with RBC (P less than 0.05). The formation of amidated C3 was abolished by the preincubation of RBC with 2'-deoxycoformycin (P less than 0.001). Amidated C3 elicited statistically significant release of superoxide, myeloperoxidase, and lactoferrin from PMN. Thus, the formation of amidated C3 by RBC deamination of adenosine triggers a cascade of complement-mediated inflammatory reactions.

Adenosine↗
PubMed2003

Erythrocyte-replaced mouse model for Haemoparasite studies: comparison of NOD/shi-scid and C.B-17/Jcl-scid mouse upon acceptability of human erythrocytes.

The erythrocyte-exchanged chimera mouse model has become to be a significant tool for studying animal and human (hu) protozoan haemoparasites, though the usefulness of this model varies depending primarily on the acceptability of xenogeneic red blood cells (RBC). To find a superior recipient in comparison with C.B-17/Jcl mouse with severe combined immuno-deficiency (scid) mutation, we examined in this report the non-obese diabetes (NOD)/shi-scid mouse, a recently available strain of SCID. When 2.5 x 10(8) of fluorescent dye-labeled hu-RBCs were transfused, C.B-17scid mouse eliminated them logarithmically by a simple linear regression, while NOD-scid mouse eradicated hu-RBCs by a unique two-step fashion, i.e., a potent but only briefly functioning RBC eradication followed by a weak steadily functioning step. The means of regression line constance +/- their standard deviations (SD) of 205 C.B-17scid and of 213 NOD-scid mice for their short- and long-lasting steps were -0.73 +/- 0.63, -0.53 +/- 0.25 and -0.16 +/- 0.10, respectively. Hu-RBC half-lives determined from these means of C.B-17scid mice and of NOD-scid mice for the short- and long-living steps were 3.6, 4.9 and 16.3 hr, respectively. Higher hu-RBC acceptability of NOD-scid mouse, especially at their long-lasting step, was also demonstrated under at an activated state of mouse innate immunity. Treatment with 1.0 mg heat-killed Candida cells caused an acceleration of hu-RBC elimination in both mouse strains but the magnitudes for the short- and long-living steps of NOD-scid mice evaluated by "stimulation index" were only 1/2.6 and 1/7.6 of C.B-17scid mice, respectively.

Animals↗
PubMed1976

Reaction of an activated complex of guinea-pig complement components, C56, with unsensitized erythrocytes and with erythrocytes carrying C3b molecule.

During the interaction of guinea-pig complement intermediate cells, EAC423, with guinea-pig C5 and C6, an activated complex of C5 and C6, C56, was demonstrated in the fluid phase of the reaction mixture. C56 also was eluted from EAC42356 which had been generated by the interaction of EAC423 with C5 and C6. Both preparations of C56 showed quite similar characteristics and were not distinguished from one another. Both were capable of reacting with unsensitized erythrocytes (E) in the presence of C7 to form EC567. Further, they were able to react with EAC43 in the absence of C7 to form EAC43568 but did react with EAC43 pretreated with C3b inactivator, dithiothreitol or N-bromosuccinimide. These results indicate that guinea-pig C56 generated on EAC423 has a tendency to dissociate into the fluid phase. Nevertheless, the dissociated C56 can bind again to intact C3b molecule on the cells. The ability of cell-bound C3b to combine with C56 may lead to localization of C56 to the cell membrane carrying C3b, resulting in acceleration of attachment of C567 to the membrane. This assumption could be supported by the finding that the replacement of E by EAC43 increased the susceptibility of the cells to lytic action of complement induced by cobra venom factor. Thus, a new function of cell-bound C3b as localizing C56 to the membrane of sensitized cells was indicated.

Animals↗
PubMed2000

Protein 4.1, a multifunctional protein of the erythrocyte membrane skeleton: structure and functions in erythrocytes and nonerythroid cells.

Protein 4.1 of red blood cells (4.1R) is a multifunctional protein essential for maintaining erythrocyte shape and membrane mechanical properties, such as deformability and stability, through lateral interactions with spectrin and actin in the skeletal network and vertical interactions with cytoplasmic domains of transmembrane proteins, glycophorin C, and band 3. The primary stucture of the major 80-kd isoform of 4.1R has been elucidated, and on the basis of this identification, the functional domains and sites for binding partners have been clarified. Posttranslational modification of 4.1 R, such as phosphorylation and proteolysis, as well as binding of regulatory proteins including calmodulin-Ca2+ to 4.1R, modulates its interactions with other membrane proteins and, consequently, the membrane functions of red blood cells. Alternative splicing occurs in the 4.1R gene, and various isoforms are expressed not only in erythroid but also in nonerythroid cells. This review introduces current knowledge on biochemical, biophysical, genetic, and functional aspects of 4.1R and its family proteins, 4.1G (general type), 4.1B (brain type), and 4.1N (neuron type), recently identified in nonerythroid cells.

Cytoskeletal Proteins↗
PubMed2001

Low cholesterol in erythrocyte membranes and high lipoperoxides in erythrocytes are the potential risk factors for cerebral hemorrhagic stroke in human.

OBJECTIVE: To explore the association of risk for human cerebral hemorrhage with blood cholesterol, free radicals, oxidation and lipoperoxidation. METHODS: 351 cerebral hemorrhage patients (CHP) in the acute phase and 100 healthy adult volunteers (HAV) were investigated by testing the contents of cholesterol (CH), lipoperoxides (LPO), nitric oxide (NO), vitamin C (VC) and vitamin E (VE) and activities of superoxide dismutase (SOD) in plasma and erythrocytes (RBC), and by assessing the contents of CH and LPO in RBC with spectrophotometric assays. RESULTS: Compared with the average values (AV) of the above biochemical parameters (BP) in the HAV group, the AV of CH in plasma and RBC, VC and VE in plasma as well as SOD in plasma and RBC in the CHP group were significantly decreased (P = 0.0000), while the AV of the LPO in plasma and RBC as well as NO in plasma in the CHP group were significantly increased (P = 0.0000). The findings of linear correlation analysis for the CHP group showed that the above biochemical parameters were significantly correlated with both intracranial hemorrhagic sizes (IHS) and neurotic functional defective scales (NDS). The findings of stepwise correlation analysis for the CHA group suggested that HIS was closely correlated with the values of CH and LPO in RBC as well as NO and VE in plasma, and that NDS was closely correlated with the values of CH and LPO in RBC as well as NO and VC in plasma. CONCLUSIONS: The findings of the present study suggest that marked low RBC cholesterol and marked high RBC lipoperoxides may constitute the potential main risk factors for human cerebral hemorrhage, and that the oxidative and lipoperoxidative stress in the CHP bodies is pathologically aggravated, leading to the oxidative and lipoperoxidative damages in the CHP.

Adult↗
PubMedDate not supplied

[Proteins of erythrocytic membrane. II. Solubilization of proteins in the membrane of human erythrocytes by chlorpromazine (author's transl)].

At the concentration above 2 mM, chlorpromazine induces partial solubilization of human erythrocytic membrane proteins. High molecular weight components such as spectrin are not extracted. Glycoproteins are preferentially released: at least five glycoprotein components are separated by acrylamide gel electrophoresis after specific staining. Other non identified proteins of the ghost external surface are also solubilized. At high concentration total solubilization of ghosts is obtained. Material extracted by chlorpromazine may be used for further protein purification.

Blood Proteins↗
PubMed1986

[Erythrocyte-plasma water exchange studied by nuclear magnetic resonance spin-spin (T2) relaxation. Relation between the time the water molecule stays in the erythrocyte and its volume].

A simple, precise and rapid pulse nuclear magnetic resonance technique for measuring the rate of water exchange across the erythrocyte membrane is presented. The effects of cell volume on cell water lifetime may be eliminated by the introduction of a cell water diffusion coefficient. This parameter is applied to the study of eleven blood samples.

Body Water↗
PubMed1987

[Blood, plasma, erythrocyte viscosity and index of erythrocyte filtration in subjects with hyperlipemia].

40 hyperlipidaemic patients (26 type II a and b, 14 type IV) and 50 healthy controls were studied. The patients were not suffering from any other pathology of note and were under no drug treatment. Blood viscosity at natural Ht and at Ht 45% and plasma viscosity were measured. Red blood cell viscosity and deformability was studied on washed red cells, poor in leucocytes and platelets and suspended in a saline phosphate buffer. The patients with hyperlipidaemia had blood viscosity higher than healthy people. Red blood cell and plasma viscosity were higher in subjects with hyperlipidaemia. There was no difference in the filtration index between the people under study. The increased blood viscosity found in people with hyperlipidaemia appears to be attributable to changes in both the plasma and the erythrocytes.

Adult↗
PubMed1985

[Assay of erythrocyte ATP by chemoluminescence. Protective action induced by pentoxifylline on the depletion of energy from stored erythrocytes].

A new method to measure erythrocyte ATP levels is used. The authors have incubated 6 whole blood samples and 7 samples containing washed red blood cells for 6 h. They measured ATP levels and confirmed an important decrease of the values during the time. If the same samples were incubated with pentoxifylline (1.4 X 10(-4) M), the ATP decrease was less relevant.

Adenosine Triphosphate↗
PubMed1985

Assessment of the thiamine nutritional status. An evaluation of erythrocyte transketolase activity, the stimulated erythrocyte transketolase activity, and the thiamine pyrophosphate effect.

The most widely accepted approach to estimation of thiamine nutrition has been the measurement of the erythrocyte transketolase activity (ETKA), the ETKA stimulated in vitro with thiamine pyrophosphate (TPP) (which is suggested to be designated ETKAS) and the percentage increase of ETKA after stimulation with TPP in vitro, called the thiamine pyrophosphate effect (TPPE). In spite of 30 years of experience in the determination of these variables doubtfulness still exists of how to assess them. On the basis of a study of a group of alcoholics and a group of non-alcoholics a system of evaluation of ETKA, ETKAS and TPPE is proposed.

Adult↗
PubMed1979

Sickled erythrocytes, hyphema, and secondary glaucoma: I. The diagnosis and treatment of sickled erythrocytes in human hyphemas.

Four patients with sickle cell hemoglobinopathies (one SC, three AS) and hyphemas were found to have more erythrocytes sickled in their anterior chambers than in their circulating venous blood. Intraocular pressure was severely elevated, despite relatively small amounts of intracameral blood. Systemic hypotensive agents were not always successful in reducing IOP, and in patients with sickle cell hemoglobinopathy, are probably contraindicated in high or repeated dose regimens. Moderate elevation of IOP in sickle cell hemoglobinopathy patients may produce rapid deterioration of visual function, perhaps because of a greater than usual effect on vascular perfusion in the central retinal artery and optic nerve. Early anterior chamber paracentesis may be the best treatment for this type of hyphema-induced secondary glaucoma.

Adolescent↗
PubMed1979

Sickled erythrocytes, hyphema, and secondary glaucoma: V. The effect of vitamin C on erythrocyte sickling in aqueous humor.

In vivo incubations of Hgb SC erythrocytes showed significantly more sickling in anterior chambers characterized by high concentrations of ascorbic acid than in anterior chambers with low concentrations of ascorbic acid (normal guinea pigs compared with scorbutic guinea pigs and normal guinea pigs compared with normal rats). Low concentrations of ascorbic acid, however, did not completely eliminate intracameral sickling. Because acetazolamide raises the concentration of aqueous humor ascorbate, it should be used with considerable discretion when treating hyphema and secondary glaucoma caused by sickle cells. Methazolamide may be more desirable.

Acetazolamide↗
PubMed1981

The micro-erythrocyte sedimentation rate in black neonates and children. Part II. A comparative study of the micro-erythrocyte sedimentation rate, C-reactive protein test and total white cell count.

The value of determination of the micro-erythrocyte sedimentation rate (ESR), testing for the presence of serum C-reactive protein (CRP) and the total white cell count (WCC) has been assessed in neonates and children, both healthy and in disease states. The results show that collective and maximum use of all three investigations aids diagnosis because these tests are simple, quick, cheap and easy to perform. Furthermore, the study has demonstrated that compared with a high ESR and WCC, the presence of CRP was the best single indicator of infection. The CRP test has the greatest predictive value and sensitivity in that it indicates the intensity of an infection as well as the patient's response to therapy.

Adolescent↗
PubMed1976

[Conversion of chimpanzee O-erythrocytes into B-erythrocytes by human alpha galactosyltransferase].

The red blood cell antigens of the ABO system are not present in all the anthropïd Primates. The Chimpanzee, particularly, shows only the two genes A and O. The alpha-galactosyl transferase, present in the human sera of group B, has been used to fix a molecule of galactose on O red cells of Chimpanzee giving them a B specificity. If the B gene was present in the Chimpanzee it could consequently be expressed on the erythrocytes. This gene, probably present in an ancestor common to the anthropoïd apes and to Man disappeared in the Chimpanzee, perhaps at the origin of species.

ABO Blood-Group System↗