Showing papers on "Red blood cell published in 1975"

Erythropoiesis and erythropoietin in hypo- and hyperthyroidism.

Abstract: Qualitative and quantitative studies of erythropoiesis in 23 patients with hypothyroidism and 21 patients with hyperthryoidism included routine hematologic evaluation, bone marrow morphology, status of serum iron, B12 and folate red blood cell mass and plasma volume by radioisotope methods, erythrokinetics and radiobioassay of plasma erythropoietin. A majority of patients with the hypothyroid state had significant reduction in red blood cell mas per kg of body weight. The presence of anemia in many of these patients was not evident from hemoglobin and hematocrit values due to concomitant reduction of plasma volume. The erythrokinetic data in hypothyroid patients provided evidence of significant decline of the erythropoietic activity of the bone marrow. Erythroid cells in the marrow were depleted and also showed reduced proliferative activity as indicated by lower 3H-thymidine labeling index. Plasma erythropoietin levels were reduced, often being immeasurable by the polycythemic mouse bioassay technique. These changes in erythropoiesis in the hypothyroid state appear to be a part of physiological adjustment to the reduced oxygen requirement of the tissues due to diminished basal metabolic rate. Similar investigations revealed mild erythrocytosis in a significant proportion of patients with hyperthyroidism. Failure of erythrocytosis to occur in other patients of this group was associated with impaired erythropoiesis due to a deficiency of hemopoietic nutrients such as iron, vitamin B12 and folate. The mean plasma erythropoietin level of these patients was significantly elevated; in 4 patients the levels were in the upper normal range whereas in the rest, the values were above the normal range. The bone marrow showed erythyroid hyperplasia in all patients with hyperthyroidism. The mean 3H-thymidine labeling index of the erythroblasts was also significantly higher than normal in hyperthyroidism; in 8 patients the index was within the normal range whereas in the remaining 13 it was above the normal range. Erythrokinetic studies also provided evidences of increased erythropoietic activity in the bone marrow. It is postulated that thyroid hormones stimulate erythropoiesis, sometimes leading to erythrocytosis provided there is no deficiency of hemopoietic nutrients. Stimulation of erythropoiesis by thryoid hormones appears to be mediated through erythropoietin.

Specificity of cell-mediated cytotoxicity against human melanoma lines: evidence for "non-specific" killing by activated T-cells.

Abstract: The specificity of cell-mediated cytotoxicity against melanoma cells in vitro has been analyzed in a large number of studies with cells both from normal and melanoma subjects. As in a number of other, recent, similar human studies, no evidence for tumour specificity was found. Effector cells in peripheral blood responsible for the cytotoxic raction were examined by cell separation methods based on red cell rosette formation and separation through Hypaque-Ficoll mixtures. The evidence suggests that non-specificity results from killing by cells separating largely in the non-sheep red blood cell rosetting fraction and which have cytotoxic specificity directed broadly to cells with abnormal membranes. Further analysis revealed that the cells were non-phagocytic and did not bear receptors for complement. They appear to be activated into cell division and to bear surface receptors for the Fc portion of IgG. Additional evidence is presented suggesting that the cells mainly responsible are activated thymus-dependent cells present in the circulation of both tumour-bearing and normal subjects.

The effects of capture, "stress," and storage of whole blood on the red blood cells, plasma proteins, glucose, and electrolytes of the winter flounder (Pseudopleuronectes americanus).

Abstract: When the blood from flounder caught in the field was compared with the blood of laboratory-maintained flounder, a number of differences were observed. Hematocrits, mean red blood cell volumes, bloo...

Erythropoietin and the differentiation of red blood cells.

Abstract: Erythropoietin is the primary factor regulating red blood cell formation in mammals and some other animals. It has been purified from plasma derived from anemic sheep and from the urine of anemic patients and is a glycoprotein. The sheep hormone has a molecular weight of 46,000 and appears to consist of a single chain. The carbohydrate and amino acid compositions, where known, are summarized, as are the known structural requirements for biological activity. Its mode of action as the inducer of red cell differentiation has been studied in marrow cell and fetal liver cell cultures. Erythropoietin interacts first with a protein receptor on its target cell causing the appearance of a cytoplasmic protein thought to be a mediator that, in turn, causes an increased rate of transcription in the target cell nuclei. There are several different species of RNA synthesized before the cells initiate hemoglobin synthesis. The effect on transcription is only indirectly dependent on DNA synthesis. Some properties of the primitive erythropoietin-responsive cell are discussed and a cellular model for blood cell differentiation is presented.

A study of B and T cells in multiple sclerosis.

Abstract: Peripheral blood T and B lymphocytes were enumerated using E and EAC red blood cell rosetting techniques. The percentage of EAC-binding cells in peripheral blood of multiple sclerosis patients is elevated (31.7 ± 2.4 S.E.M.) when compared with the percentage in healthy controls (18.5 ± 1.1 S.E.M.). The total T cell percentage is not significantly lower in multiple sclerosis than in controls, but fewer T cells in patients with multiple sclerosis are able to bind 10 or more red blood cells.

Hemoglobin function in the vertebrates: an evolutionary model.

Abstract: Comparative data on quaternary structure, cooperativity, Bohr effect and regulation by organic phosphates are reviewed for vertebrate hemoglobins. A phylogeny of hemoglobin function in the vertebrates is deduced. It is proposed that from the monomeric hemoglobin of the common ancestor of vertebrates, a deoxy dimer, as seen in the lamprey, could have originated with a single amino acid substitution. The deoxy dimer has a Bohr effect, cooperativity and a reduced oxygen affinity compared to the monomer. One, or two, additional amino acid substitutions could have resulted in the origin of a tetrameric deoxy hemoglobin which dissociated to dimers on oxygenation. Gene duplication, giving incipient alpha and beta genes, probably preceded the origin of a tetrameric oxyhemoglobin. The origin of an organic phosphate binding site on the tetrameric hemoglobin of an early fish required only one, or two, amino acid substitutions. ATP was the first organic phosphate regulator of hemoglobin function. The binding of ATP by hemoglobin may have caused the original elevation in the concentration of ATP in the red blood cells by relieving end product inhibition of ATP synthesis. The switch from regulation of hemoglobin function by ATP to regulation by DPG may have been a consequence of the curtailment of oxidative phosphorylation in the red blood cell. The basic mechanisms by which ATP and DPG concentrations can respond to strss on the oxygen transport system were present before the origin of an organic phosphate binding site on hemoglobin. A switch from ATP regulation to IP5 regulation occurred in the common ancestor of birds.

Blood volume in inbred strain balb/c, cba/j and c57bl/10 mice determined by means of 59fe-labelled red cells and 59fe bound to transferrin.

Abstract: Circulating red blood cell (RBC) and plasma volume was determined in male inbred strain BALB/c, CBA/J and C57BL/10 mice by parallel use of the 59Fe-labelled RBC dilution and the dilution of 59Fe bound to transferrin. The whole blood volumes values derived from the venous haematocrit and plasma volume were about double the values calculated from the venous haematocrit and circulating RBC volume. Comparison of the two methods thus explains the marked differences in different studies of blood volume in mice and shows that correct values can be obtained only by parallel measurements of RBC and plasma volume by separate methods, or by correcting the venous haematocrit to whole body haematocrit. Combination of the labelled RBC method and the 59Fe-transferrin method showed the blood volume values in the above strains of mice to be 10.35 +/- 0.16, 7.32 +/- 0.10 and 7.94 +/- 0.15 ml/g b.w. respectively. The ratio of whole body to venous haematocrit in these strains was was 57.3 +/- 1.6%, 68.0 +/- 1.8% and 69.5 +/- 2.2%. Significant interstrain differences were demonstrated in RBC, plasma and blood volume and in the venous and whole body haematocrit and their ratio.

The β-adrenergic receptor-adenyl-cyclase system of rat reticulocytes

Abstract: Non-nucleated red blood cells from rats contain adenyl cyclase, the activity of which is predominantly localized in the reticulocytes. Basal enzyme activities in membrane preparations from reticulocyte-rich blood (pretreatment of rats with acetyl-phenylhydrazide: about 60% reticulocytes) are about 5 times higher than in preparations from reticulocyte-poor blood (untreated animals: 2–3% reticulocytes). The enzyme activities are stimulated 10-fold by sodium fluoride (10−2 M) and 6 to 8-fold by isoprenaline (10−4 M). Adenyl cyclase activities in membrane preparations from reticulocyte-rich and reticulocyte-poor blood can be ascribed to identical enzymes since identical apparent K m (ATP; 3×10−4 M), K a (isoprenaline; 3×10−6 M) and K i (propranolol vs. isoprenaline; 3×10−7 M) values were obtained in both preparations. Besides NaF, only phenylethanolamine derivatives with β-adrenergic receptor stimulant properties were effective as stimulators of adenyl cyclase activity. The affinities (apparent K a values) of the investigated compounds decreased in the order isoprenaline—hexoprenaline—fenoterol—salbutamol—adrenaline—terbutaline—noradrenaline—phenylephrine. For maximal intrinsic activity, the catechol structure was essential; the relative intrinsic activities of resorcinol derivatives did not exceed 0.6. The isoprenaline-stimulated adenyl cyclase activities in erythrocyte membrane preparations were competitively inhibited by β-adrenergic blocking drugs, the affinities (apparent K i values) decreasing in the order prindolol—penbutolol—propranolol—practolol. The dextrorotatory enantiomers of penbutolol and propranolol were 1/100 to 1/200 as active as the resp. levorotatory enantiomers. From experiments with α-adrenergic agonists (e.g. phenylephrine) and antagonists (e.g. phentolamine), it is concluded that α-adrenergic receptors do not interfere with the β-adrenergically-mediated cAMP formation in these particular membranes. A variety of hormones and drugs known to stimulate adenyl cyclase activities in various tissues, e.g. ACTH, glucagon, STH, erythropoietin, prostaglandin E 1 etc. did not affect adenyl cyclase activity in reticulocyte-rich erythrocyte membrane preparations. In contrast to adenyl cyclase activity, phosphodiesterase activities in erythrocyte membrane and cytoplasmic fractions were only twice as high in reticulocyterich as in reticulocyte-poor preparations. From the experiments described, it is obvious that the adenyl cyclase of the rat reticulocyte is subject to monovalent-hormonal, i.e. β-sympathomimetic stimulation. Moreover, the premature red blood cell provides a useful model for quantitative studies of the interaction of drugs with the β-adrenergic receptor.

[7] Erythropoietin: Assay and study of its mode of action

Abstract: Publisher Summary Erythropoietin, a glycoprotein hormone, is the physiological regulator of red blood cell formation in higher animals. Relative anoxia causes an increase in the level of circulating erythropoietin. Conversely, under conditions of decreased oxygen need or increased supply, there is a decrease in the amount of circulating erythropoietin. Because of the high degree of specificity of the hormone (that is, only erythroid tissue formation is affected), because the end product—the erythrocyte—is well characterized, and because it can be studied in vitro, the system is an attractive one for biochemical investigation of differentiation. Bioassays for erythropoietin depend on the fact that labeled iron, when injected into animals, is incorporated only in cells still in the process of synthesizing hemoglobin; mature erythrocytes neither take up iron nor exchange their heme iron with the plasma. Thus, newly formed red cells can, in effect, be counted by measuring the amount of label in the peripheral blood after sufficient Lime is allowed for complete clearance of the plasma iron. This chapter also discusses briefly about: starved rat assay, plethoric mouse assay, in vitro assay, methods for the study of the mode of action of erythropoietin in vitro, and methods for measuring hemoglobin synthesis.

Activity rhythms of enzymes in human red blood cell suspensions

Abstract: We have established the presence of a rhythm in the activity of 4 enzymes in in‐vitro cell suspensions of human red blood cells. Glucose 6‐phosphate dehydrogenase and glutamate oxaloacetate transaminase demonstrated semicircadian patterns of activity, while acid phosphatese and acetylcholine esterase exhibited circadian activity rhythms. The ratios between the highest to lowest activities varied from 2:1 to 10:1 among the various enzymes. The affinity of glucose 6 phosphate dehydrogenase to its substrate and coenzyme remained constant throughout the cycle. No evidence was obtained for the presence of a soluble inhibitor at the lower levels of the activity. Sonication of hemolysates with low glucose 6 phosphate dehydrogense activity yielded additional activity comparable to that of the peak activity. Sonication of hemolysates from the time of the peak activity did not change the original activity. The observations point to a role of the cell membrane in the biological clock.

Lymphocyte subpopulations. Human red blood cell rosettes.

Abstract: Human red blood cells (HRBC) even without prior neuraminidase treatment, could form rosettes with human peripheral blood lymphocytes in vitro. The optimum conditions for forming these rosettes were a pH of 7-0 and a medium with 5% bovine serum albumin (BSA). Rosette proportions became much less at a different pH or using lower concentrations of BSA, or replacing BSA with foetal calf sera (FCS) or human sera. Rosette formation was also promoted by prior treatment of HRBC or lymphocytes with neuraminidase. Mixed rosettes of HRBC and sheep red blood cells (SRBC) showed that HRBC receptors were detectable only on lymphocytes that possessed SRBC receptors, suggesting that HRBC rosette-forming cells were probably thymus-derived (T) cells. Next, the properties of human red blood cell (HRBC) and sheep red blood cell (SRBC) rosette-forming cells were investigated by comparing the ability of human peripheral blood lymphocytes to form these two types of rosettes after treatment with various inhibitory reagents. HRBC rosettes were relatively more resistant to inhibition with: (1) proteolytic agents, such as trypsin, alpha-chymotrypsin and pronase; (2) anti-thymocyte serum (ATS); (3) metabolic inhibitors, such as sodium azide and 2,4-dinitrophenol (DNP); (4) cytochalasin B. On further incubation after trypsinization, the lymphocytes recovered some ability to form SRBC rosettes, but continued to lose more of their capability to form HRBC rosettes. All these results were regarded as circumstantial evidence that the HRBC rosettes might represent a subpopulation of human T lymphocytes.

Pyruvate kinase in malaria host–parasite interaction

Abstract: THE mammalian malaria host–parasite systems seem particularly useful for studies aimed at elucidating the biochemical mechanisms of such interactions. During the vertebrate phase of their life cycles the malaria organisms are intracellular parasites of the red cell. The mature mammalian host red cell is also relatively simple metabolically; its energy metabolism is solely that of Embden–Meyerhof glycolysis and it also lacks the capacity for protein synthesis. We therefore studied several aspects of red cell glycolysis in monkeys heavily infected with Plasmodium knowlesi and mice heavily infected with P. berghei. In both these systems we have found an increase in red blood cell adenosine triphosphate (ATP) and a decrease in red cell 2,3-diphosphoglycerate (DPG). We also have evidence that these malaria parasites introduce a pyruvate kinase isozyme into their host red cells in amounts sufficient to alter red cell glycolysis. First, glycolytic intermediate data demonstrate an in vivo increase in pyruvate kinase activity in infected red cells; second, there is an increase in pyruvate kinase Vmax activity in infected cells; and third, gel electrophoretic patterns show a new pyruvate kinase isozyme in infected cells. We suggest that this alteration in red cell glycolysis is in a direction favourable to the parasite because it will increase red cell ATP at the expense of red cell DPG.

Hypotonic hemolysis of human red blood cells: a two-phase process.

Abstract: Previous use of hemolysis time measurement to determine permeability coefficients for the red blood cell membrane rested on the assumption that cells swelling in a hypotonic medium hemolyzed immediately on reaching critical volume. By preswelling red cells to various volumes prior to immersion in hemolytic solutions we extrapolate to the hemolysis time of red cells immersed at critical volume and thereby find a significant period of time during which the cells apparently remain in a spherical form prior to release of hemoglobin. Revised estimates of permeability coefficients follow from including this spherical (nonswelling) phase. In addition, the appreciation of a characteristic time period during which the membrane is under tension provides new opportunity to study physical and chemical properties of the membrane.

The cytotoxic effector potential of some common non-lymphoid tumors and cultured cell lines with phytohemagglutinin and heterologous anti-erythrocyte antisera.

Abstract: We have found that a) phytohemagglutinin can induce red blood cell cytolysis by non-lymphoid tumors and cell lines, b) rabbit anti-chicken red blood cell antibody but not turkey anti-chicken red blood cell antibody can mediate an antibody-directed cellular cytotoxicity type of cytotoxicity utilizing P815Y mastocytoma cells or rat embryo fibroblasts as effectors, and c) none of these cell line effectors was capable of killing metabolically active cultured cell line targets in the presence of phytohemagglutinin

The abnormal surface characteristics of the red blood cell membrane in congenital dyserythropoietic anaemia type II (HEMPAS).

Abstract: The red blood cell membranes of patients with congenital dyserythropoietic anaemia Type II (CDA-II) were found to be abnormal. They had altered antigenic characteristics, decreased electrophoretic mobility, decreased sialic acid content, and abnormal filtration through polycarbonate filters. Proteins extracted from the CDA-II erythrocytes showed a different banding pattern on polyacrylamide gels compared to normal erythrocytes. Erythrocytes from clinically unaffected siblings and parents showed similar but less striking abnormalities of antigenic surface characteristics and banding patterns on polyacrylamide gels with nearly normal surface charge, sialic acid content, and filtration properties. These studies suggest a correlation between the degree of membrane abnormality and the clinical state of the CDA-II family member, demonstrate the erythrocyte in the heterozygote state is not normal, and support the concept of CDA-II as an autosomal recessive disease.

Acquired red cell pyruvate kinase deficiency in leukemias and related disorders.

Abstract: The authors studied red blood cell pyruvate kinase activity of 202 patients with various hemopathies. A PK deficiency of moderate grade was found in 39% of patients with acute myeloblastic leukemias, in 57% of those with primary medullary insufficiency without aplasia, in 61% of those with refractory sideroblastic anemia. The PK deficiency was often associated with deficiencies of other red cell enzymes. The mechanism of such enzyme abnormalities was discussed with the hypothesis of a post-translational molecular alteration.

Fetal-tumor membrane associated antigens: genetic and immunological implications.

Abstract: SANDERS, B. G. & KLINE, K. 1975. Fetal-tumor membrane associated antigens: genetic and immunological implications. Trans. Amer. Micros. Soc., 94: 470-479. Immunology as a tool has been utilized to document membrane changes occurring during the process of development as well as membrane changes occurring with the onset of leukemia. Chicken red blood cell membranes express a fetal antigen (CFA) at preand posthatching. CFA is lost with aging of the chicken and reappears on the red blood cell membrane of adult leukemic chickens. The mode of membrane antigen loss and reappearance were followed. Additionally, the genetic mechanism coding for the reappearance of CFA was considered. The reappearance of CFA does not have to involve the derepression of a repressed fetal gene as had been assumed. A differentiation antigen hypothesis is now favored. The use of immunotherapy for treatment of cancers of this type is now questionable, since the fetalcancer antigen has been found to be present on normal stem cells which are undergoing maturation.

The effect of lead on the red cell membrane

Abstract: Conformational changes have been shown in the proteins of the red blood cell membrane, induced by lead poisoning. Evidence that the change in spatial arrangement of proteins is believed to be responsible for inhibition of the sodium (Na+)/potassium (K+) ATPase of the RBC membrane is presented.

The allogeneic effect: M-locus differences substitute for differences in the H-2 major histocompatibility complex.

Abstract: The primary immune response against sheep red blood cells in T cell-deficient spleen cell cultures from nude mice was tested in the absence and presence of allogeneic spleen cells. The allogeneic spleen cells differed either in regard to the major histocompatibility complex (H-2) or only with respect to the M-locus. Surprisingly the M-locus different spleen cells were almost as efficient in enhancing the anti-sheep red blood cell response in nude cultures as were the cells differing on the complete H-2 complex. Evidence is presented that AKR anti-θ serum sensitive T cells are responsible for the M-locus-dependent effect described. This effect is shown to be mediated by a factor released from actived T cells stimulated in M-locus different mixed lymphocyte cultures. Since almost identical parameters have been observed both in the M-locus-dependent situation as in the “classical” allogeneic situation we concluded that an allogeneic effect can be induced by T cells responding to a complete set of the major histocompatibility complex (H-2) as well as to lymphocyte-activating determinants (M-locus) alone.