Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0002871 (anemia)
 52,094 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mutations in the Steel locus, encoding a growth factor (Steel factor or SF) or c-kit, the gene encoding its receptor, result in severe anemia in the mouse. In the present study, we have addressed the mechanism of synergistic growth activation, at the cellular level, by SF and GM-CSF using the blast cells of acute myeloblastic leukemia (AML blasts). Our data indicate that SF drastically alleviates the requirement in cell interaction for blast colony formation in most of the samples tested. Analysis of cultures performed in the presence of SF and GM-CSF at different cell concentrations, ranging from 1,000 to 20,000 cells, suggested a single limiting element, i.e., the blast clonogenic cell, while 2 or more limiting elements were found in cultures stimulated with GM-CSF alone, suggesting interacting cell populations. The presence of membrane-bound SF was detected by immunofluorescence, suggesting the possibility that secreted or membrane-bound SF may, at least in part, contribute to the density-dependent growth of AML blasts. In all samples tested, SF appears to increase the responsiveness of AML blasts to GM-CSF, as demonstrated by a 3-fold decrease of GM-CSF half efficient concentration on addition of SF to the cultures. Exposure of AML blasts to SF did not affect GM-CSF receptor expression, suggesting that this increase in GM-CSF responsiveness is likely to occur at the postreceptor level. Interestingly, 2 of 15 AML samples surveyed did not respond to SF, and were both of the myelomonocytic or monocytic subtype, classified as M4 and M5, respectively.
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PMID:Product of the Steel locus can replace leukemic cell interaction. 138 39

A hitherto undescribed form of congenital dyserythropoietic anaemia is reported. The patient was severely anaemic and hydropic at birth and is now 8 years old. She has a moderate normochromic normocytic anaemia. HbF level of 50%, reticulocyte count of 5-12% and hyperbilirubinaemia. Bone marrow smears showed intense normoblastic erythroid hyperplasia with morphological evidence of dyserythropoiesis; the most common dysplastic features were basophilic stippling of polychromatic erythroblasts and erythrocytes and marked abnormalities of nuclear shape in polychromatic erythroblasts. Electron microscope studies showed that some polychromatic erythroblasts and several erythrocytes contained inclusions which were rounded, elongated or irregular in outline or were doughnut-shaped. These inclusions consisted of compact masses of tubules and saccules which may represent smooth endoplastic reticulum together with Golgi cisternae. The ultrastructural studies also revealed peculiar membrane-bound cylindrical structures in a rare late erythroblast, and phagocytosed erythroblasts within some macrophages. The technique of combined Feulgen microspectrophotometry and 3H-thymidine autoradiography demonstrated a pile-up of early polychromatic erythroblasts in the G1 and G2 phases of the cell cycle, indicating a prolongation of, or an arrest at, these phases. Furthermore, nearly a quarter of all erythroblasts failed to incorporate 3H-leucine into protein. Thus the anaemia appeared to be due to a combination of disordered erythroblast function, increased ineffectiveness of erythropoiesis and peripheral haemolysis. The primary defect may be an excessive synthesis or impaired degradation of intracytoplasmic membranes.
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PMID:Congenital dyserythropoietic anaemia with novel intra-erythroblastic and intra-erythrocytic inclusions. 165 63

Particles of chicken anemia agent (CAA) negatively stained with uranyl acetate were found to be 26.5 nm in diameter. The surface detail evident on the particles indicated that the virus capsid was composed of 32 structural subunits arranged as in a class P = 3 icosahedron with a triangulation number of 3. Using mouse monoclonal antibodies to CAA and a gold-labeled goat anti-mouse IgG, CAA-specific structures were observed by thin-section electron microscopy in infected MDCC-MSB1 cells and in thymic lymphocytes from experimentally infected chicks. These consisted of electron-dense, granular, non-membrane-bound nuclear inclusions, which were often ring-shaped, and cytoplasmic accumulations of microtubules. Aggregates of virus-like particles were sometimes observed in the nuclei of infected MDCC-MSB1 cells. The nucleolar involvement that is characteristic of the morphogenesis of parvoviruses was not observed with CAA.
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PMID:Chicken anemia agent: an electron microscopic study. 224 1

Anemia is a common side effect of cisplatin, especially after repeated infusions. The primary mechanisms is a myelosuppression caused by cisplatin's interference with iron metabolism, resulting in a lower count of red cell precursors. Some authors report a hemolytic anemia similar to penicillin-induced anemia, in which hemolysis is caused by an antiglobulin antibody directed against red cell membrane-bound cisplatin. The authors report two cases of cisplatin-induced anemia and suggest that the immune-complex hypothesis is responsible for hemolysis. The first case of carboplatin-induced hemolysis is also reported. Mechanisms of hemolysis and clinical practice are discussed.
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PMID:Platin salts-induced hemolytic anemia: cisplatin- and the first case of carboplatin-induced hemolysis. 779 80

Hemoglobin Constant Spring (HbCS) is the most common nondeletional alpha-thalassemic mutation and is an important cause of HbH-like disease in Southeast Asia. HbCS variants have an almost normal mean cell volume (MCV) and the anemia is more severe when compared with other alpha-thalassemic variants. We explored the pathobiology of HbCS red blood cells (RBCs) because the underlying cause(s) of this MCV "normalizing" effect of HbCS and the more severe anemia are not fully explained. HbCS containing RBCs are distinctly overhydrated relative to deletional alpha-thalassemia variants, and the derangement of volume regulation and cell hydration occurs early in erythroid maturation and is fully expressed at the reticulocyte stage. Furthermore, the membrane rigidity and membrane mechanical stability of HbCS containing RBCs is increased when compared with HbH and alpha-thalassemia-1 trait RBCs. In seeking the cause(s) underlying these cellular alterations we analyzed membranes from HbCS and deletional alpha-thalassemic variants and found that in addition to oxidized beta-globin chains, oxidized alpha cs-globin chains are also associated with the membranes and their skeletons in HbCS containing RBCs. We propose that the membrane pathology of HbCS variants is caused by combination of the deleterious effects induced by membrane-bound oxidized alpha cs- and beta-globin chains. The membrane alterations induced by alpha cs chains are more akin to those induced by beta A-globin chains than those induced by the alpha A-globin chains that accumulate in the beta-thalassemias. Thus, each globin chain, alpha cs, alpha A, beta A, appears to produce its own form of membrane perturbation.
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PMID:The unusual pathobiology of hemoglobin constant spring red blood cells. 905 61

In 1970 at the University of Texas MD Anderson Hospital, Houston TX, we attended a patient with malignant lymphoma and "lymphosarcoma cell leukaemia". The malignant cells were large with fine granular cytoplasm. The patient was febrile without positive cultures and exhibited wasting resembling "graft-vs-host" disease. Both his lymphoma cells collected from the blood, and his serum, exerted strong cytotoxicity toward a battery of human tumour cell lines established in culture. We reported him as the first case of a new entity; "cytotoxic lymphoma". Later, elsewhere, natural killer (NK) cells were characterized, and cases of malignant lymphomas arising from large granular lymphocytes were described, as those of NK cells. Malignant NK cells constitutively express Fas ligand (L), both membrane-bound (m) and soluble (s). Upon binding FasL Fas receptor (R)-positive hosts cells succumb to apoptotic death. Patients with FasL-producer lymphoma cells suffer from anaemia, neutropenia, hepatotoxicity and autoimmunity. The FasL-->FasR system regulates normal lymphocyte homeostasis. This system is used by the placental trophoblast against maternal lymphocytes; by transplants against host lymphocytes; and by donor lymphocytes exerting graft-vs-host-reaction. In tumour immunology, FasR+ tumour cells can be killed by FasL+ lymphocytes and, vice versa, FasL+ tumour cells can induce apoptotic death of FasR+ host lymphocytes ("counterattack on lymphocytes"). Some tumour cells co-express FasL, FasR and bcl-2 and not only escape programmed cell death but also utilize the FasL-->FasR system as an autocrine growth loop ("counterattack on apoptosis").
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PMID:Malignant lymphoma arising from natural killer cells: report of the first case in 1970 and newer developments in the FasL-->FasR system. 946 34

Phospholipid asymmetry in the red blood cell (RBC) lipid bilayer is well maintained during the life of the cell, with phosphatidylserine (PS) virtually exclusively located in the inner monolayer. Loss of phospholipid asymmetry, and consequently exposure of PS, is thought to play an important role in red cell pathology. The anemia in the human thalassemias is caused by a combination of ineffective erythropoiesis (intramedullary hemolysis) and a decreased survival of adult RBCs in the peripheral blood. This premature destruction of the thalassemic RBC could in part be due to a loss of phospholipid asymmetry, because cells that expose PS are recognized and removed by macrophages. In addition, PS exposure can play a role in the hypercoagulable state reported to exist in severe beta-thalassemia intermedia. We describe PS exposure in RBCs of 56 comparably anemic patients with different genetic backgrounds of the alpha- or beta-thalassemia phenotype. The use of fluorescently labeled annexin V allowed us to determine loss of phospholipid asymmetry in individual cells. Our data indicate that in a number of thalassemic patients, subpopulations of red cells circulate that expose PS on their outer surface. The number of such cells can vary dramatically from patient to patient, from as low as that found in normal controls (less than 0.2%) up to 20%. Analysis by fluorescent microscopy of beta-thalassemic RBCs indicates that PS on the outer leaflet is distributed either over the entire membrane or localized in areas possibly related to regions rich in membrane-bound alpha-globin chains. We hypothesize that these membrane sites in which iron carrying globin chains accumulate and cause oxidative damage, could be important in the loss of membrane lipid organization. In conclusion, we report the presence of PS-exposing subpopulations of thalassemic RBC that are most likely physiologically important, because they could provide a surface for enhancing hemostasis as recently reported, and because such exposure may mediate the rapid removal of these RBCs from the circulation, thereby contributing to the anemia.
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PMID:Membrane phospholipid asymmetry in human thalassemia. 953 18

We investigated the effects of iron deficiency anemia, iron repletion, and iron chelation by deferoxamine on protein kinase C (PKC) activity, an enzyme that plays a crucial role on T lymphocyte proliferation. The study involved 23 control (C), 18 pairfed (PF), and 24 iron deficient (ID) mice or ID mice that were repleted for 3 (n = 14), 7 (n = 17), or 14 (n = 14) days. The low iron (0.09 mmol iron/kg) and iron-supplemented (0.9 mmol iron/kg) diets were fed to mice for 53 days. Mean hemoglobin, hematocrit, and liver iron stores of ID mice were one third of those of C mice. Lymphocyte proliferation was reduced (P < 0.05) in spleen and purified T cells in ID but not PF mice. In concanavalin A, phytohemagglutinin, and anti-CD3 antibody-treated and untreated cells that were incubated in serum-free and serum-containing medium, PKC activity was significantly (P < 0.05) reduced in ID but not PF mice and returned to normal before correction of anemia. In mitogen-treated cells, while the ratios of membrane-bound to cytosol activity increased nearly seven-fold (from 0.4-0.63 in resting cells to 1.43-7.23) in spleen cells from C, PF, and repleted mice and 11-fold in T cells (P < 0.005), they remained below 1 in ID mice suggesting reduced translocation. In vitro iron chelation by deferoxamine for 120 min prior to cell activation reduced (P < 0.05) PKC activity by 46-60% in C and PF and 28-53% in ID mice. The data suggest that: 1) it is iron-deficiency but not anemia or differences in the proportion of immunocompetent T cells that reduced PKC activity in cells from ID mice; 2) reduced PKC translocation may play an important role on altered lymphocyte proliferation and associated functions in iron-deficient individuals.
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PMID:In vivo and in vitro iron deficiency reduces protein kinase C activity and translocation in murine splenic and purified T cells. 1041 47

Homeostatic mechanisms regulating intracellular concentrations of Ca2+ at a low level are prerequisites for maintaining the integral and cytoskeletal structure of erythrocytes under normal physiological conditions. The present study was undertaken to assess the contribution of Ca2+ homeostasis in modifying red-cell stability in hamsters, during the anaemia caused by Leishmania donovani. Erythrocytes from the infected animals became increasingly fragile as infection progressed. This fragility may be the result of a gradual change in membrane permeability, as indicated by enhanced uptake of 45Ca2+. The increase in cytosolic Ca2+ and decrease in membrane-bound Ca2+ observed indicate the release of Ca2+ from the membrane store, leading to [Ca2+]i accumulation in the later stages of the post-infection period. Decline in the efficacy of Ca(2+)-effluxing enzyme may also contribute to the enhanced [Ca2+]i level, with subsequent degradation of membrane proteins in the erythrocytes of the infected animals. Marked inhibition of proteolytic degradation by the Ca(2+)-dependent thiol protease inhibitor leupeptin, with concomitant thiol depletion, indicates the involvement of Ca(2+)-induced thiol protease in the observed degradation of membrane proteins. The results indicate that an altered Ca2+ homeostasis in erythrocytes following leishmanial infection causes enhanced cellular accumulation of Ca2+, which in turn may lead to haemolysis in experimental visceral leishmaniasis.
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PMID:Altered calcium homeostasis and membrane destabilization in erythrocytes of hamsters infected with Leishmania donovani. 1072 23

The proband is a 50 year-old woman born from a consanguineous marriage. She has been suffering from angina pectoris since the age of 38 and underwent coronary bypass surgery for three-vessel disease at 48. The presence of low plasma levels of total cholesterol and high density lipoprotein (HDL) cholesterol (2.4 and 0.1 mmol/l) and apo AI (<15 mg/dl), associated with corneal lesions and a mild splenomegaly suggested the diagnosis of Tangier disease. However, none of the other features of Tangier disease, including hepatomegaly, anemia and peripheral neuropathy, were present. The analysis of the dinucleotide microsatellites located in chromosome 9q31 region demonstrated that the proband was homozygous for the alleles of D9S53, D9S1784 and D9S1832. The mother and son of the proband, both with low levels of HDL cholesterol, shared one of the proband's haplotypes, whereas neither of these haplotypes was present in the normolipidemic proband's sister. The sequence of ATP-binding cassette transporter 1 (ABC1-1) cDNA obtained by reverse transcription-PCR (RT-PCR) of total RNA isolated from cultured fibroblasts showed that the proband was homozygous for a C>T transition in exon 13, which caused a tryptophane for arginine substitution (R527W). This mutation was confirmed by direct sequencing of exon 13 amplified from genomic DNA. It can be easily screened, as the nucleotide change introduces a restriction site for the enzyme Afl III. R527W substitution occurs in a highly conserved region of the NH2 cytoplasmic domain of ABC1 protein. R527W co-segregates with the low HDL phenotype in the family and was not found in 200 chromosomes from normolipidemic individuals.
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PMID:A point mutation in ABC1 gene in a patient with severe premature coronary heart disease and mild clinical phenotype of Tangier disease. 1125 60


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