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)

Erythropoietin (Epo) is a glycoprotein hormone produced in the kidney in response to hypoxia or anaemia. In acute renal failure (ARF) anaemia also occurs and current opinion is that Epo production is depressed with inappropriately low plasma levels throughout the uraemic phase. Our study was designed to determine the excretion of Epo in patients with ARF. Fifty-nine ventilated patients were studied, 39 with ARF and continuous veno-venous haemofiltration therapy (group 1) and 13 patients with normal renal function who served as a control group (group 2). All patients with ARF were anaemic and needed a mean transfusion of 0.6 units/day. Values for vitamin B12, folic acid, serum iron and ferritin were normal. While patients with normal renal function had Epo values within the normal range, patients with ARF had significantly higher values at the onset of haemofiltration therapy. Mean Epo (mean +/- SEM) values on days 0-2 were 92.6 +/- 11.7 mU/ml in group 1 and 16.5 +/- 6.4 mU/ml in group 2 (p < 0.0002). Epo levels declined in group 1 to 49 +/- 10.5 mU/ml on days 9 and 10 compared to 23 +/- 9.1 mU/ml in group 2 (ns). These values were maintained until the end of the observation period. No differences were seen between oliguric and non-oliguric patients. Our data show that patients with ARF have increased Epo levels at the beginning of the disease with a strong tendency to decrease, suggesting that there might be inadequate Epo levels during the course of acute renal failure.
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PMID:Erythropoietin in patients with acute renal failure and continuous veno-venous haemofiltration. 924 56

High-dose chemotherapy is increasingly accepted as a treatment approach in a number of tumour types. However, there are controversies surrounding its efficacy and there is a need to consider its safety. In view of this, much effort has been directed towards the provision of adequate supportive care strategies to prevent toxicities and to ameliorate myelosuppression. Severe anaemia and its associated symptoms, for example, fatigue can have a debilitating effect on a patient's quality of life and often necessitates red blood cell transfusions. Erythropoietin, a glycoprotein hormone which stimulates red blood cell production, has been established for the treatment of anaemia in patients with chronic renal insufficiency. It is currently approved in most countries for treating anaemia associated with cancer, and its role is emerging especially in patients undergoing high-dose chemotherapy. This paper gives an overview of the studies conducted to date with epoetin alfa (recombinant human erythropoietin) in patients receiving allogeneic and autologous bone marrow transplants or peripheral blood stem cells in conjunction with high-dose chemotherapy. In addition, there are some novel clinical applications for epoetin alfa: for example, in delayed anaemia, as a supportive strategy prior to high-dose chemotherapy and as a synergistic enhancer of blood progenitor cell mobilisation in combination with granulocyte-colony-stimulating factor (G-CSF).
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PMID:Haematological toxicities associated with dose-intensive chemotherapy, the role for and use of recombinant growth factors. 934 59

The purpose of this review is to give an update of the recent progress in research on erythropoietin (Epo), the hormone that regulates red blood cell production. Epo is a glycoprotein with a molecular mass of approx 30 kDa, which circulates in plasma of the human with 165 amino acids with three N-linked and one O-linked acidic oligosaccharide side chains in the molecule. Both the alpha (39% CHO) and beta (24% CHO) forms are available for clinical use, and there does not appear to be any difference in the pharmacokinetics of these two forms of Epo. Radioimmunoassays and enzyme-linked immunoabsorbant (ELISA) assays are available in a kit form. Serum levels of Epo in normal human subjects range between 1 and 27 mmu/ml or approx 5 pmol/l. It seems clear that the cells in the adult mammalian kidney which produce Epo are the interstitial cells in the peritubular capillary bed and the perivenous hepatocytes in the liver. Expression of the human Epo gene sequences that direct expression in the kidney are located 6-14 kilobases 5' to the gene; whereas the sequences that control hepatocyte-specific expression are located within 0.7 KS to the 3'-flanking region and 0.5 KS to the 5'-flanking region. The signal transduction pathways postulated to be involved in the expression of Epo are: kinases A, G and C; both a constitutive factor and a second hypoxia-inducible factor-1 (HIF-1) located in the 5' end of an hypoxia inducible enhancer region of the Epo gene; and reactive oxygen species. The primary target cell in the bone marrow acted on by Epo is the colony-forming unit erythroid (CFU-E) which has the highest number of Epo receptors. It has been postulated that Epo decreases the rate which Epo-dependent progenitor cells undergo programed cell death (apoptosis). There are two major signal transduction pathways activated by the Epo receptor: the JAK2-STAT5 pathway and the ras pathway. Both pathways involve tyrosine phosphorylation. The approved clinical uses of Epo are the anemias associated with end-stage renal disease, cancer chemotherapeutic agents, and patients with HIV infection receiving AZT. Other anemias reported to respond to Epo therapy are anemia of prematurity, rheumatoid arthritis, and myelodysplasia. Other uses of Epo under investigation are in perioperative surgery and preoperative autologous blood donation.
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PMID:Erythropoietin: physiologic and pharmacologic aspects. 940 40

This review has two objects: a brief recapitulation of the biological background of erythropoietin (EPO), and a review of its clinical utilization in hematology. EPO, both in its naturally occurring and recombinant form (rH-EPO), is a single chain glycoprotein with an approximate molecular weight of 30.000 to 34.000 kD. Its heavy glycosilation is essential for its activity in vivo, since asialoEPO is readily cleared by the heptic asialoglycoprotein receptor. This impedes the recombinant molecule's synthesis in biologic cultures other than mammalian cells (Chinese hamster's ovary cells), and inevitably increases costs. If in vitro glycosilation of E. coli-derived rH-EPO could be achieved, the clinical utilization of the product would be considerably enhanced, most especially when very high doses are necessary, as discussed later. There is no antigenic diversity between natural and recombinant EPO, so that out of the enormous clinical experience only one single case of immunization has been recorded. Almost paradoxically there are however three published cases of pure red cell aplasia (PRCA) caused by immunization against autologous EPO. It is now established that in adults EPO is synthetized in renal peritubular interstitial cells, although some residual activity remains in the liver. Hypoxia results in a rapid induction of EPO expression, although the role of the oxygen sensor system is still debated. Cellular targets are notoriously erythroid progenitors and precursors (BFU-E, CFU-E, early and intermediate erythroblasts). The global erythropoietic activity resulted in various effects (proliferation, differentiation, survival), but most probably each single effect is integrated with and complementary of the others. The utilization of rH-EPO in hematologic diseases came much later than its dramatic success in renal anemia. A variety of tools useful for assessing the possible beneficial effects of rH-EPO in clinical hematology has been proposed, among which a low level of endogenous EPO is a good predictor for therapeutic success. 'Hemopathic' anemia can be subdivided into three categories: patients with normal erythropoiesis due to inadequate EPO production (anemia of prematurity), patients with depressed but nonclonal erythropoiesis (chemotherapy, lymphoid malignancies such as multiple myeloma-MM and chronic lymphatic leukemia-CCL) and patients with at least partially clonal anemia, such as paroxysmal nocturnal hemoglobinuria (PNH), hemoglobinopaties, myelodysplastic syndromes (MDS) and others. Results in the first category of patients are, as expected, prompt and satisfactory with physiologic doses. Although therapeutic strategy for MM is moving fast to curative intents, the utilization of rH-EPO is indicated for the control of anemia in conservatively-treated patients. In the third category the most important and controversial area is MDS. Significant erythropoietic results are generally obtained in about 20% of patients; however, the association with G-CSF has considerably enhanced the response rate. In the field of bone marrow transplantation there is an inadequate production of endogenous EPO in the allogeneic setting, and randomized studies have shown the benefits of rH-EPO in this situation. However, the most important results have been obtained in post-major-ABO incompatible PRCA, when the removal of the recipient's isohemagglutinins does not resolve the anemia. High and very high doses of rH-EPO (even over 500 UI/kg/day for 2-4 weeks) may resolve this occasionally quite refractory condition. Although extremely expensive, this treatment may be life-saving when an otherwise successful allogeneic transplant is at the risk of failure because of this relatively uncommon but severe immunohematologic complication.
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PMID:[Erythropoietin: biochemical characteristics, biologic effects, indications and results of use in hematology]. 948 78

A 47-year-old woman was admitted to our hospital for evaluation of general fatigue and dyspnea. She had been diagnosed with progressive systemic sclerosis (PSS) when she was 39 years of age, on the basis of Raynaud's phenomenon, proximal sclerosis, and pigmentation of the skin. On admission, her blood pressure was 206/128 mmHg. Funduscopy revealed grade III (Keith & Wagener) hypertensive retinopathy. Laboratory data showed positivity for anti-nuclear antibody and anticardiolipin beta 2 glycoprotein I antibody, and the plasma level of renin activity (PRA) was abnormally high. Chest X-ray and UCG revealed massive pericardial effusion. On the second hospital day, she was operated on for pericardiodiaphragmatic fenestration. The volume of pericardial effusion amounted to more than 2000 ml. Post operative malignant hypertension persisted. Laboratory data showed thrombocytopenia, hemolytic anemia, and acute renal failure. We diagnosed scleroderma renal crisis (SRC) associated with antiphospholipid syndrome. Following the initiation of angiotensin converting enzyme inhibitor (ACE-I) combined with calcium antagonist and alpha-one blocker, her blood pressure and PRA decreased. She also had been treated with aspirin 81 mg daily. These therapies were effective in recovering the platelet count and stopped the progression of anemia and renal failure. Although either the finding of large pericardial effusion or SRC is associated with poor prognosis in PSS, this case has had a good clinical course. In this case, the findings suggested that anti-phospholipid antibody may have contributed to the pericarditis and SRC.
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PMID:[A case of scleroderma renal crisis with massive pericardial effusion and positivity on antiphospholipid antibody test]. 965 14

Erythropoietin (EPO) is the glycoprotein hormone that promotes differentiation of erythroid progenitor cells in bone marrow. The normal kidney produces EPO to maintain erythrocyte for oxygen supply. This hormone activity was found in the serum of anemic animals in the 1890s. Renal failure results in severe anemia because of reduced EPO production, therefore anemia patients expected EPO treatment for long time. However, this was difficult due to the limited amount of EPO. Many researchers have tried to isolate EPO since the 1950s. Finally Miyake and Goldwasser purified highly active EPO from the urine of aplastic anemia patients. Since then, the characteristics and structural information from the purified material accelerated the cloning of the EPO gene. Mammalian cells were essential to produce EPO, because EPO contains 40% carbohydrate that plays some important roles in its activity, stability and biosynthesis. In 1984, two groups succeeded in cloning the EPO gene and expressing this gene in mammalian cells. Recombinant human EPO is currently available for anemia treatment. In this paper, we review production in mammalian cells, molecular characterization, especially carbohydrate moieties, and clinical applications of recombinant EPO.
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PMID:The production of recombinant human erythropoietin. 970 92

Prior to 1972, the increased cardiovascular morbidity and mortality that diabetics endure had been attributed to vascular disease. In 1972, Rubler et al. proposed the existence of a diabetic cardiomyopathy based on their expereince with four adult diabetic patients who suffered from congestive heart failure (CHF) in the absence of discernable coronary artery disease, valvular or congenital heart disease, hypertension, or alcoholism. Alternative explanations for CHF, such as anemia and vascular and renal disease in these four patients, gave rise to criticisms, but a wave of subsequent studies in the 1970s and 1980s provided credence to this new disease entity. This review of the studies done since 1972 appears to support the concept of a diabetic cardiomyopathy independent of atherosclerotic cardiovascular disease. The exact mechanism is still questionable, and several mechanisms have been proposed including small and microvascular disease, autonomic dysfunction, metabolic derangements, and interstitial fibrosis. However, the weight of evidence leans toward the development of fibrosis, possibly caused by the accumulation of a peroxidase acid schiff (PAS)-positive glycoprotein, leading to myocardial hypertrophy and diastolic dysfunction.
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PMID:Diabetic cardiomyopathy. 985 79

The membrane glycoprotein encoded by the env gene of either the polycythemia- or anemia-inducing spleen focus-forming virus (SFFVp or SFFVa, respectively) is responsible for the induction of erythroleukemia in mice. It has been shown that the SFFVp glycoprotein, gp55, interacts with the erythropoietin receptor (EPO-R) and promotes EPO-independent proliferation of an EPO-R-expressing hematopoietic cell line, Ba/F3 (Li et al., Nature 343:762, 1990). We show here that when residues within the transmembrane (TM) sequence of an SFFVp gp55 are altered based on the sequences of the anemia-inducing gp55s by a methionine-to-isoleucine (M-I) substitution, a di-leucine deletion (dLL), or both, the resulting mutants display an attenuated phenotype that resembles an SFFVa: they induce milder erythroproliferative disease without polycythemia in vivo and are unable to promote EPO-independent cell proliferation in vitro. The dLL mutation directly interferes with EPO-R binding by decreasing the affinity of gp55 for the receptor. On the other hand, the M-I mutation hampers the full mitogenic activation of EPO-R while having no effect on receptor binding and asserts a dominant negative effect over the wild-type SFFVp gp55. Two other sequence changes within the TM sequence did not affect the biological activities of the SFFVp gp55. These results indicate that the TM sequence of the SFFV env glycoprotein plays a prominent role in SFFV-induced erythroleukemogenesis through its influence on the mitogenic activation of EPO-R.
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PMID:Role of the transmembrane sequence of spleen focus-forming virus gp55 in erythroleukemogenesis. 987 16

Erythropoietin (EPO) is a glycoprotein hormone produced principally by the kidney and is the major stimulus for erythropoiesis. Recombinant human EPO has now been biosynthesized and is available for clinical use, particularly in patients with renal failure. EPO has been reported to be effective in treating anaemia due to chronic renal failure. It has been used in pregnancy to correct anaemia following renal transplantation with graft dysfunction. We report here the case of a post-renal transplant patient who became pregnant and developed severe anaemia which was not related to iron, B12, or folate deficiency. Her anaemia was successfully treated with EPO with no evidence of rejection or significant graft dysfunction following therapy. She tolerated EPO very well, and there was a successful outcome of the pregnancy. This case has encouraged us to conclude that EPO has a useful role in the treatment of anaemia in pregnant women following renal transplantation.
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PMID:Erythropoietin therapy in a pregnant post-renal transplant patient. 988 25

Anemia-inducing factor (AIF) was isolated from gastric cancer tissue; however, the human placenta used as the volume of AIF for further analysis did not prove sufficient. This substance was named placental anemia-inducing factor (PAIF). PAIF directly reduces the number of erythrocytes in vitro and reduces the RBC count in rabbits to 80% when i.v. administration of 27 microg/kg of body weight is given. The aim of this study is to better define PAIF and to examine whether the identifical substance expresses on either the surface or in the cytoplasm of established gastric cancer cell lines. PAIF is a glycoprotein with about 20 KD, whose 17 amino acid residues of N terminus were sequenced after Edman treatment. The N-terminus of PAIF were determined as Lqcyncpnptadcktav. This is homologous with that of CD59, which is thought as a regulator of membrane attack complex of complement system. Expression of PAF or CD59 in four established gastric cancer cell lines were examined by indirect immunofluorescence method and by Northern blot hybridization. The cells (1 x 106) were seeded into plastic plates for three days and reacted overnight at 4 degrees C in 0.5 ml of PBS with anti-PAIF polyclonal antibody or with anti CD59 rat monoclonal antibody. Both PAIF and CD59 were stained positively on the surface and/or in the cyroplasm. The total RNAs were prepared from the four kinds of cell lines and normal human lymphocytes. CD59 mRNA was probed in all cell lines by BamH1-EcoR1 fragment of PSRa CD59. The signal levels of MKN-28, MKN-45 and KATO-III were stronger than that of MKN-74, whereas the signal of normal lymphocytes was the lowest. Although there is no decisive evidence that PAIF is exactly the same substance as CD59, and although the biological functions of these two substances are conflictive, and still to be further investigated, the 17 amino acid residues of N-terminus of PAIF expressed in gastric cancer cells were homologous with those of CD59. A derivative of CD59 may exist in gastric cancer.
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PMID:Anemia-inducing factor expressed in gastric cancer is homologous with complement regulatory factor CD59? 989 75


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