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

Human falciparum malaria, caused by Plasmodium falciparum infection, results in 1 to 2 million deaths per year, mostly children under the age of 5 years. The two main causes of death are severe anemia and cerebral malaria. Malarial anemia is characterized by parasite red blood cell (RBC) destruction and suppression of erythropoiesis (the mechanism of which is unknown) in the presence of a robust host erythropoietin response. The production of a host-derived erythropoiesis inhibitor in response to parasite products has been implicated in the pathogenesis of malarial anemia. The identity of this putative host factor is unknown, but antibody neutralization studies have ruled out interleukin-1beta, tumor necrosis factor alpha, and gamma interferon while injection of interleukin-12 protects susceptible mice against lethal P. chabaudi infection. In this study, we report that ingestion of P. chabaudi-infected erythrocytes or malarial pigment (hemozoin) induces the release of macrophage migration inhibitory factor (MIF) from macrophages. MIF, a proinflammatory mediator and counter-regulator of glucocorticoid action, inhibits erythroid (BFU-E), multipotential (CFU-GEMM), and granulocyte-macrophage (CFU-GM) progenitor-derived colony formation. MIF was detected in the sera of P. chabaudi-infected BALB/c mice, and circulating levels correlated with disease severity. Liver MIF immunoreactivity increased concomitant with extensive pigment and parasitized RBC deposition. Finally, MIF was elevated three- to fourfold in the spleen and bone marrow of P. chabaudi-infected mice with active disease, as compared to early disease, or of uninfected controls. In summary, the present results suggest that MIF may be a host-derived factor involved in the pathophysiology of malaria anemia.
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PMID:Macrophage migration inhibitory factor release by macrophages after ingestion of Plasmodium chabaudi-infected erythrocytes: possible role in the pathogenesis of malarial anemia. 1072 28

Hematopoietic progenitor cells from Fanconi anemia (FA) group C (FA-C) patients display hypersensitivity to the apoptotic effects of gamma interferon (IFN-gamma) and constitutively express a variety of IFN-dependent genes. Paradoxically, however, STAT1 activation is suppressed in IFN-stimulated FA cells, an abnormality corrected by transduction of normal FANCC cDNA. We therefore sought to define the specific role of FANCC protein in signal transduction through receptors that activate STAT1. Expression and phosphorylation of IFN-gamma receptor alpha chain (IFN-gammaRalpha) and JAK1 and JAK2 tyrosine kinases were equivalent in both normal and FA-C cells. However, in coimmunoprecipitation experiments STAT1 did not dock at the IFN-gammaR of FA-C cells, an abnormality corrected by transduction of the FANCC gene. In addition, glutathione S-transferase fusion genes encoding normal FANCC but not a mutant FANCC bearing an inactivating point mutation (L554P) bound to STAT1 in lysates of IFN-gamma-stimulated B cells and IFN-, granulocyte-macrophage colony-stimulating factor- and stem cell factor-stimulated MO7e cells. Kinetic studies revealed that the initial binding of FANCC was to nonphosphorylated STAT1 but that subsequently the complex moved to the receptor docking site, at which point STAT1 became phosphorylated. The STAT1 phosphorylation defect in FA-C cells was functionally significant in that IFN induction of IFN response factor 1 was suppressed and STAT1-DNA complexes were not detected in nuclear extracts of FA-C cells. We also determined that the IFN-gamma hypersensitivity of FA-C hematopoietic progenitor cells does not derive from STAT1 activation defects because granulocyte-macrophage CFU and erythroid burst-forming units from STAT1(-/-) mice were resistant to IFN-gamma. However, BFU-E responses to SCF and erythropoietin were suppressed in STAT(-/-) mice. Consequently, because the FANCC protein is involved in the activation of STAT1 through receptors for at least three hematopoietic growth and survival factor molecules, we reason that FA-C hematopoietic cells are excessively apoptotic because of an imbalance between survival cues (owing to a failure of STAT1 activation in FA-C cells) and apoptotic and mitogenic inhibitory cues (constitutively activated in FA-C cells in a STAT1-independent fashion).
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PMID:The Fanconi anemia protein FANCC binds to and facilitates the activation of STAT1 by gamma interferon and hematopoietic growth factors. 1084 98

The potential of the antibiotics chloramphenicol succinate (CAPS) and thiamphenicol (TAP) to induce aplastic anaemia in the female BALB/c mouse was investigated. CAPS was administered at 2000 mg/kg, and TAP at 850 mg/kg, daily by gavage, for 17 days. At 1, 13, 22, 41, 98 and 179 days after the final dose of each antibiotic, mice (n = 4 or 5) were sampled for haematological examination and haematopoietic stem cell assays. Both CAPS and TAP induced significant reductions in red blood cell count, haematocrit and haemoglobin values at day 1 post dosing; counts of colony-forming units-erythroid and colony-forming units-granulocyte-macrophage, were similarly significantly decreased at this time. All these reduced parameters returned towards normal at days 13 and 22. At days 41, 98 and 179, results for all haematological values and stem cell assays in both CAPS- and TAP-treated mice compared with the controls; there was no evidence of a reduction in peripheral blood values or bone marrow parameters at the later sampling points, as would be expected in a developing or overt bone marrow aplasia. We therefore consider that the administration of CAPS and TAP, which have been associated with the development of aplastic anaemia in man, induce a reversible anaemia, but not a chronic bone marrow aplasia, when given at haemotoxic dose levels for 17 days in the BALB/c mouse.
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PMID:An assessment of chloramphenicol and thiamphenicol in the induction of aplastic anaemia in the BALB/c mouse. 1103 26

The contribution of granulocyte-macrophage colony-stimulating factor (GM-CSF), a hematopoietic and immunoregulatory cytokine, to resistance to blood-stage malaria was investigated by infecting GM-CSF-deficient (knockout [KO]) mice with Plasmodium chabaudi AS. KO mice were more susceptible to infection than wild-type (WT) mice, as evidenced by higher peak parasitemia, recurrent recrudescent parasitemia, and high mortality. P. chabaudi AS-infected KO mice had impaired splenomegaly and lower leukocytosis but equivalent levels of anemia compared to infected WT mice. Both bone marrow and splenic erythropoiesis were normal in infected KO mice. However, granulocyte-macrophage colony formation was significantly decreased in these tissues of uninfected and infected KO mice, and the numbers of macrophages in the spleen and peritoneal cavity were significantly lower than in infected WT mice. Serum levels of gamma interferon (IFN-gamma) were found to be significantly higher in uninfected KO mice, and the level of this cytokine was not increased during infection. In contrast, IFN-gamma levels were significantly above normal levels in infected WT mice. During infection, tumor necrosis factor alpha (TNF-alpha) levels were significantly increased in KO mice and were significantly higher than TNF-alpha levels in infected WT mice. Our results indicate that GM-CSF contributes to resistance to P. chabaudi AS infection and that it is involved in the development of splenomegaly, leukocytosis, and granulocyte-macrophage hematopoiesis. GM-CSF may also regulate IFN-gamma and TNF-alpha production and activity in response to infection. The abnormal responses seen in infected KO mice may be due to the lack of GM-CSF during development, to the lack of GM-CSF in the infected mature mice, or to both.
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PMID:Granulocyte-macrophage colony-stimulating factor-deficient mice have impaired resistance to blood-stage malaria. 1111 98

Somatic mosaicism has been observed previously in the lymphocyte population of patients with Fanconi anemia (FA). To identify the cellular origin of the genotypic reversion, we examined each lymphohematopoietic and stromal cell lineage in an FA patient with a 2815-2816ins19 mutation in FANCA and known lymphocyte somatic mosaicism. DNA extracted from individually plucked peripheral blood T cell colonies and marrow colony-forming unit granulocyte-macrophage and burst-forming unit erythroid cells revealed absence of the maternal FANCA exon 29 mutation in 74.0%, 80.3%, and 86.2% of colonies, respectively. These data, together with the absence of the FANCA exon 29 mutation in Epstein-Barr virus-transformed B cells and its presence in fibroblasts, indicate that genotypic reversion, most likely because of back mutation, originated in a lymphohematopoietic stem cell and not solely in a lymphocyte population. Contrary to a predicted increase in marrow cellularity resulting from reversion in a hematopoietic stem cell, pancytopenia was progressive. Additional evaluations revealed a partial deletion of 11q in 3 of 20 bone marrow metaphase cells. By using interphase fluorescence in situ hybridization with an MLL gene probe mapped to band 11q23 to identify colony-forming unit granulocyte-macrophage and burst-forming unit erythroid cells with the 11q deletion, the abnormal clone was exclusive to colonies with the FANCA exon 29 mutation. Thus, we demonstrate the spontaneous genotypic reversion in a lymphohematopoietic stem cell. The subsequent development of a clonal cytogenetic abnormality in nonrevertant cells suggests that ex vivo correction of hematopoietic stem cells by gene transfer may not be sufficient for providing life-long stable hematopoiesis in patients with FA.
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PMID:Somatic mosaicism in Fanconi anemia: evidence of genotypic reversion in lymphohematopoietic stem cells. 1122 73

Treatment with granulocyte colony-stimulating factor plus erythropoietin may improve haemoglobin levels in patients with ringsideroblastic anaemia (RARS) and reduce bone marrow apoptosis. We studied bone marrow from 10 RARS patients, two of whom were also investigated after successful treatment. Mononuclear, erythroid and CD34+ cells were analysed with regard to proliferation, apoptosis, clonogenic capacity and oncoprotein expression, in the presence or absence of Fas-agonist, Fas-blocking antibody 2 and caspase-3 inhibitor. During culture, RARS bone marrow cells showed higher spontaneous apoptosis (P < 0.05) and caspase activity (P < 0.05)) than bone marrow cells from healthy donors. Eight out of nine patients had reduced growth of erythroid colony-forming units (CFU-E) (< 10% of control) and granulocyte-macrophage CFU (CFU-GM) (< 50% of control) from CD34+ cells. Fas ligation increased apoptosis and decreased colony growth equally in RARS and controls, but caused significantly more caspase activation in RARS (P < 0.01). Fas-blocking antibody showed no significant inhibitory effect on spontaneous apoptosis or ineffective haematopoiesis, as measured using phosphatidylserine exposure, the terminal deoxynucleotide transferase-mediated dUTP-biotin nick-end labelling technique, caspase activity or clonogenic growth. Caspase inhibition reduced apoptosis, increased proliferation and enhanced erythroid colony growth from CD34+ cells in RARS, but showed no effect on normal cells. CFU-E improved > 1000% after successful treatment. Thus, erythroid apoptosis in RARS is initiated at the CD34+ level and growth factor treatment may improve stem cell function. Enhanced caspase activation at the stem cell level, albeit not mediated through endogenous activation of the Fas receptor, contributes to the erythroid apoptosis in RARS.
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PMID:Apoptosis in refractory anaemia with ringed sideroblasts is initiated at the stem cell level and associated with increased activation of caspases. 1126 77

Erythropoietin (EPO), granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage stimulating factor (GM-CSF) are currently licensed for use in cancer patients and play a significant role in the management of anemia and neutropenia following myeloblative chemotherapy. EPO was the first recombinant hematopoietic growth factor to be used clinically after a number of clinical trials which demonstrated its effectiveness in treating mild to moderate cancer-associated anemia with or without concomitant chemotherapy (particulary cisplatin). An extensive research has been made for the improvement of the quality of life with EPO therapy, however, when formally assessed, variable effects of this important treatment have been observed. Recently, EPO has been shown to significantly accelerate hematopoietic reconstitution after peripheral blood stem cell transplantation (PBSCT) resulting in reduced infection rates. Both, G-CSF and GM-CSF have been shown, in numerous trials, to shorten the period of chemotherapy-induced neutropenia, with reduction in attendant morbidity and to mobilize PBSC. In addition, administration of both cytokines after PBSCT significantly reduced the use of antibiotics and duration of hospitalization suggesting an economic benefit. The narrower therapeutic window of GM-CSF at higher doses accounts for the fact that it is used much less frequently than G-CSF. To date, none of the growth factors used clinically has been shown to stimulate thrombopoiesis. Although thrombopoietin (TPO) has been found to induce megakaryocyte differentiation in vitro, it is unlikely to enter routine clinical use for treatment of post-chemotherapy thrombocytopenia, since results of clinical trials are not very encouraging, mainly because TPO is difficult to schedule and platelet aggregation may occur. Recently, innovative chimeric growth factor receptor agonists have been synthesized. Synthokine (SC-55494) (a high-affinity human IL-3 receptor ligand analog), myelopoietin (MPO) (activates human IL-3 and G-CSF receptors) and promegapoietin (PMP) (stimulates the human IL-3 and c-mpl receptors) were found to be multilineage hematopoietic growth factors and are currently undergoing clinical trials. Preliminary results suggest that these compounds may have a major impact on the management of myeloablative chemotherapy because of their ability to enhance platelet recovery in addition to their neutrophil restorative activity.
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PMID:Human hematopoietic growth factors: old lessons and new perspectives. 1132 88

Ginseng is a traditional Chinese medicine which has been used in treating anemia for thousands of years. It is composed of a lot of components. The main component is total saponin of panax ginseng (TSPG), which contains more than 20 ginsenosides including Rg1, Rb1 and so on. Previous studies have reported that total saponin of panax ginseng could promote hematopoiesis by stimulating proliferation of human erythroid grogenitor cells CFU-E and BFU-E, however, it had different effects on CFU-GM reported by various laboratories. In this study, CFU-GM assay was adopted to observe the ginsenosides Rg1 and Rb1's effects on the proliferation of human marrow grannulocyte-macrophage progenitor cells. The results showed that Rg1 and Rb1 had obvious promotive effect on the proliferation of CFU-GM, and the increasing rates of colony formation were up to (70.6 +/- 6.8)% and (65.1 +/- 6.3)%, respectively. There was no inhibiting effect on CFU-GM in high concentrations of Rg1 and Rb1. It is suggested that Rg1 and Rb1 can stimulate the proliferation of human granulocyte-macrophage progentors. The results of TSPG's various effects on CFU-GM might be caused by different contents of ginsenosides in TSPG used in different laboratories.
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PMID:[Effects of Ginsenosides Rg1 and Rb1 on Proliferation of Human Marrow Granulocyte-Macrophage Progenitor Cells] 1257 29

Diffuse uptake of F-18 fluorodeoxyglucose (FDG) by the whole skeleton has been described in case of bone marrow stimulation resulting from treatment with colony-stimulating factors (CSFs): granulocyte CSF or granulocyte-macrophage CSF. The authors describe such an aspect of diffuse FDG uptake by the bone marrow during the follow-up of rectal cancer in a patient with anemia and recently treated thrice weekly by erythropoietin. To their knowledge, such an aspect of diffuse FDG uptake by the skeleton, revealing the bone marrow stimulation by erythropoietin, has not yet been reported.
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PMID:Diffusely increased F-18 FDG uptake in bone marrow in a patient with acute anemia and recent erythropoietin therapy. 1297 5

Recombinant human erythropoietin (r-EPO) has been used in Myelodysplastic Syndrome (MDS) patients with anaemia since the early nineties. In low-risk MDS patients, other haemopoietic growth factors (HGFs) (granulocyte-colony stimulating factor, G-CSF, granulocyte-macrophage-colony stimulating factor, GM-CSF, and interleukin 3, IL-3) have been used to synergise the effects of r-EPO on erythroid growth and to increase neutrophil count in patients with severe neutropenia. In high-risk MDS, or in patients with post-MDS AML, myeloid HGFs have been used to push blasts into the S-phase, thus increasing their sensitivity to antiblastic drugs. Several trials have shown that r-EPO can increase haemoglobin levels and improve QoL in patients with anaemia associated to MDS. The selection of patients with a high probability of response to HGFs is based on the careful consideration of several clinical and biological parameters, i.e., among others, basal EPO and transfusional needs, disease duration, FAB or WHO subtypes, and IPSS score. Treatment of anaemic MDS patients with HGFs should become "patient oriented" and different types, schedules, and duration of treatment have to be designed according to the specific criteria which most likely predict, for each individual patient, the best chance of responding favourably to therapy.
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PMID:Haemopoietic growth factors in myelodysplastic syndromes: towards patient-oriented therapy? 1594 26


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