Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0002874 (aplastic anemia)
 5,905 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Human erythropoietin, derived from urine of patients with aplastic anemia, has been purified to apparent homogeneity. The seven-step procedure, which included ion exchange chromatography, ethanol precipitation, gel filtration, and adsorption chromatography, yielded a preparation with a potency of 70,400 units/mg of protein in 21% yield. This represents a purification factor of 930. The purified hormone has a single electrophoretic component in polyacrylamide gels at pH 9, in the presence of sodium dodecylsulfate at pH 7, and in the presence of Triton X-100 at pH 6. Two fractions of the same potency and molecular size, by sodium dodecyl sulfate gel electrophoresis, but differing slightly in mobility at pH 9, were obtained at the last step of fractionation. The nature of the difference between these two components is not yet understood.
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PMID:Purification of human erythropoietin. 1 67

The marrow concentration of erythropoietic precursors was examined in normal donors and patients with idiopathic aplastic anemia using a plasma clot culture system. On time course observations the heterogeneity of human erythroid precursors assayable in culture was demonstrated. To evaluate human erythropoiesis in vitro, the benzidine-positive colonies were divided into three groups: small colony, containing 8-50 cells; medium-sized colony, containing 50-500 cells; and large colony, containing more than 500 cells. The majority of the large colonies assumed the morphology of erythropietic bursts (BFU-E) consisted of several subcolonies. The small colonies were counted as CFU-E1, the medium-sized as CFU-E2, and the large as BFU-E to evaluate the erythroid precursor cell compartment in aplastic anemia. The marrow concentration of CFU-E1 and CFU-E2 was shown to be quantitatively diminished in aplastic anemia. In addition, there was no ability of the marrow cells from aplastic patieints to grow BFU-E in vitro even in the presence of a large dose of erythropoietin. This lack of BFU-E colony growth may play an important role in the mechanism of the erythropoietic deficiency in aplastic anemia.
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PMID:Studies on hematopoietic stem cells: XI. Lack of erythroid burst-forming units (BFU-E) in patients with aplastic anemia. 45 93

The level of erythropoietin (Ep) was measured in sera and urine from aplastic anemia patients. Increased levels of Ep were demonstrated in sera from all 25 patients studied. An elevated level of Ep was found in the urine of 17 of 23 patients in whom the urine was tested. No correlation between blood hemoglobin and Ep level was observed. A higher serum Ep level was noted in patients with aplastic anemia than in patients with sideropenic anemia of the same severity. To explain the discrepancy diminished Ep consumption in bone marrow of aplastic anemia patients is discussed.
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PMID:Erythropoietin in aplastic anemia. 50 54

Drug like aspirin, indomethacin, phenylbutazone, chloroquine and quinine have been reported to induce agranulocytosis, aplastic anaemia and leukemia. These drugs are also known to interfere with the prostaglandin system at one point or another. Since prostaglandins are known to be involved in the maturation and differentiation of macrophage-granulocyte progenitor cells, in erythropoietin mediated erythropoiesis and in the functional capabilities of leukocytes, it is proposed here that these haematological abnormalities by these drugs could be due to their affect on the prostaglandin system.
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PMID:Prostaglandins and drug induced agranulocytosis, aplastic anaemia and leukemia. 55 Jan 46

Oxymetholone, a steroid of proven clinical value in the treatment of refractory anemia, was without effect on endogenous or erythropoietin-mediated heme synthesis in fetal mouse liver cell cultures. This conclusion applied both when the cells were exposed to oxymetholone prior to culturing with erythropoietin and when the steroid was present in the cultures simultaneously with erythropoietin. Unlike those steroids having a direct effect on erythroid cells, oxymetholone also failed to increase the proportion of erythropoietin responsive cells in DNA synthesis. The relevance of these observations to the therapeutic benefit of oxymetholone is discussed. While the possibility that oxymetholone has to be metabolized to an active form cannot be excluded, the results suggest that oxymetholone does not seem to be erythropoietically active by a direct effect on erythroid cells. The fact that it is a successful therapeutic agent in some patients with aplastic anemia may be due to its proven ability to increase endogenous erythropoietin levels or to reduce ineffective erythropoiesis.
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PMID:Oxymetholone and erythropoiesis: failure to detect an effect in fetal mouse liver cell cultures. 59 Apr 7

The concentration and erythropoietin dependence of erythropoietic progenitor cells (CFU-E) were examined in 13 patients with aplastic anaemia at different stages of their disease. The CFU-E incidence was shown to be quantitatively diminished in aplastic anaemia but tended to recover to normal values if the disease recovered. In addition the CFU-E showed a qualitatively different response to stimulation by erythropoietin, being resistant to low concentrations but responsive to concentrations greater than 0.2 U/ml whereas there was a linear response in the controls up to 0.5 U/ml.
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PMID:Erythroid colony forming cells in aplastic anaemia. 60 75

The results of the erytropoietin level determination in serum and urine of patients with congenital anemias are presented and compared to the results obtained in children with acute aplastic anemias. Three patients with congenital hypoplastic anemia Diamond-Blackfan, two with Fanconi's anemia, one with congenital pancythopenia with hyperplastic marrow and five patients with acute aplastic anemia were studied. The increased serum erythropoietin level was found in every patient whose blood hemoglobin was less than 12g%. Erythropoietin was detected in nonconcentrated urine when serum erythropoietin level was higher than 0,5 units/ml. The statistically significant negative correlation between the serum erythropoietin level and blood hemoglobin concentration was found. In two patients suffering from congenital anemias, in whome the significantly increased erythropoietin level (about 1.0 units/ml) was detected, increased ammount of hemoglobin F in peripheral blood as well as increased MCV--signs of so called "stress" erythropoiesis-were noted. The results presented, together with the results obtained by other authors, indicate that congenital anemias studied here are not due to the disturbance in erythropoietin production.
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PMID:[Erythropoietin in congenital anemias in children]. 61 97

Results of the investigation of 3 children aged from 2 to 7,5 with diagnosed aplastic anemia of Fanconi type are presented. Two children were females and one child was a male. Their illness symptoms appeared at the age of one, three and four respectively. All three patients had similar symptomes: palenes, tiredness, epistaxis, appearance of hemorrhagic syndrome and delayed growth. The following anomalies were also present: small size, microcephaly, mandibular hypoplasia, high palate and malformation of the urinary tract. In one child ductus Botalli persistens was also revealed. The laboratory findings showed presence of pancytopenia of the blood and increased level of both iron and erythropoietin in the serum. The karytype of two children revealed several cells with broken chromatin and with polyploid and tetraploid cells. The meiogram showed presence of all cells in bone marrow but in lowered number. Celularity I.
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PMID:[Congenital aplastic anemia-Fanconi]. 61

Pure red cell aplasia is a selective aplasia of the marrow erythroid cells. Unlike aplastic anemia, the marrow has a normal cellularity and the patients generally have normal leukocyte and platelet blood counts. The congenital form of the disease occurs in the firlst 1 1/2 years of life and is often responsive to corticosteroids. The acquired form may be secondary to infections, drugs, chemicals, or hemolytic anemia (aplastic crisis). In these cases it is often acute and self-limited with cessation of the infection or drug ingestion. It may also be secondary to systemic lupus erythematosus, rheumatoid arthritis, acute severe renal failure, severe nutritional deficiency, or diverse neoplasms, and may remit with treatment of the primary condition. When a thymoma is present, it should be resected since a remission is produced in 29 per cent of these patients. The remaining patients have an acquired primary form of the disease that tends to be chronic and in some cases may have an immune pathogenesis. A cytotoxic immunoglobulin inhibitor of the marrow erythroid cells or erythropoietin has been described and these patients may respond to prednisone and/or to cytotoxic immunosuppressive drugs such as cyclophosphamide and 6-mercaptopurine. Pure red cell aplasia appears to be more common than the literature has revealed and has stimulated much investigation into an immune pathogenesis for marrow failure.
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PMID:Diagnosis and treatment of pure red cell aplasia. 78 16

To explore the possible role of cell-mediated suppression of erythropoiesis in acquired aplastic anemia, we studied the effect of peripheral blood lymphocytes from seven patients with aplastic anemia on erythroid-colony formation by normal human bone marrow in an in vitro plasma clot-culture system. Varying numbers of peripheral blood lymphocytes (0.5 to 6 X 10(5) cells) were cocultured with 6 X 10(5) normal bone-marrow cells in the presence of 2 IU of erythropoietin for seven days. Peripheral blood lymphocytes from five of the seven patients with aplastic anemia caused a 79 to 94 per cent reduction of erythroid-colony formation. Thus, at a peripheral blood lymphocyte concentration of 2 X 10(5) cells, the numbers of erythroid colonies formed (control vs. experimental) were 374 +/- 16 (S.E.M.) vs. 22 +/- 6, 48 +/- 4, 50 +/- 16, 80 +/- 4 and 27 +/- 3. These results suggest that some patients with aplastic anemia possess a population of lymphocytes capable of suppressing in vitro erythropoiesis.
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PMID:Suppression of erythroid-colony formation by lymphocytes from patients with aplastic anemia. 83 Feb 63


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