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Query: UMLS:C0002871 (anemia)
 52,094 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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.
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PMID:Erythropoiesis and erythropoietin in hypo- and hyperthyroidism. 111 76

Seven patients with sickle cell anemia were treated with oxymetholone for at least 2 mo. Markedly increased basal rates of hemolysis and erythropoiesis were confirmed. The urinary erythropoietin excretion was either normal or lower than expected for the red cell mass, and an expanded blood volume was due primarily to an increased plasma volume. After androgen therapy, six patients demonstrated more than a fivefold increase in urinary erythropoietin, with an increase in red cell mass ranging from 17%-75% above the control value. All showed a decline in serum iron level to the 25-75 mug/100 ml range within 4 wk after the start of therapy. Less marked changes followed lower oxymetholone doses. Reversible hepatic toxicity, with a serum bilirubin concentration exceeding 50 mg/100 ml, occurred in one patient. Androgenic hormone therapy may be useful for selected adult patients with sickle cell disease when severe anemia contributes to disease morbidity.
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PMID:Oxymetholone treatment for sickle cell anemia. 112 26

The effects of sera from anephric rabbits on the rate of heme synthesis in erythroid cells were studied in vitro in rabbit bone marrow cultures. Sera from nephrectomized rabbits significantly (p smaller than 0.05) inhibited 59-Fe incorporation into heme in normal rabbit bone marrow cultures incubated with erythropoietin (ESF) when compared with the response in control culutres with normal serum and ESF. This inhibitory activity increased exponentially with increasing concentrations of the serum in cultures suggesting that a higher concentration of the inhibitor is present in uremia and may be the result of the failure to excrete the inhibitor. This suggests that the retention of this inhibitor may play an important role in the mechanism of the anemia of uremia. The inhibitor of heme synthesis is a low molecular weight substance.
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PMID:Studies on an inhibitor of erythropoiesis. II. Inhibitory effects of serum from uremic rabbits on heme synthesis in rabbit bone marrow cultures (38483). 112 79

A high negative correlation (coefficient similar to 0.9) between increased 59Fe absorption from a diagnostic 0.56 mg 59Fe2+ dose and the depletion of available storage iron was observed in menstruating and pregnant women, fullterm and premature infants, blood donors, patients with infections, inflammations, tumors, hepatic cirrhosis, gastric surgery, increased urogenital or gastrointestinal blood loss. The increased diagnostic 59Fe2+ absorption is a reliable and sensitive indicator of at least depleted iron stores or prelatent iron deficiency as caused by iron malnutrition or maldigestion, increased iron requirement in pregnancy, infancy, urogenital or gastrointestinal blood loss. Although the messenger system which signalyzes the depletion of iron stores to the iron absorbing enterocytes of the duodenal and jejunal mucosa is not yet known available storage iron seems to control intestinal iron absorption under normal and the great majority o pathological condition in humans. Anemia per se or high erythropoietin levels in blood do not influence iron absorption since patients with even severe erythroblastic hypoplasia, aplastic anemia and megaloblastic anemia due to vitamin B12 deficiency absorb iron according to their iron stores. An only mild hyperplasia of the erythropoietic system in the bone marrow does also not effect iron absorption which was still under the control of available storage iron in patients with hereditary spherocytosis, nonspherocytic congenital hemolytic anemia due to glucose-6-phosphate dehydrogenase deficiency, acquired hemolytic anemia and vitamin B12 deficiency induced megaloblastic anemia..
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PMID:Intestinal iron absorption under the influence of available storage iron and erythroblastic hyperplasia. Comparative studies in children with hereditary spherocytosis, nonspherocytic enzymopenic hemolytic anemia, acquired hemolytic anemia, vitamin B12 deficiency induced megaloblastic anemia, erythroblastic hypoplasia and aplastic anemia. 113 Jan 21

An 18-yr-old female with chronic active hepatitis developed a severe anemia due to a lack of red cell production. Her bone marrow showed many large proerythroblasts but an almost complete lack of more mature erythroblasts. Incubation of the marrow cells in a normal medium with erythropoietin concentrate led to increased erythropoiesis as indicated by the development of mature erythroblasts as well as a ninefold increase in hemoglobin synthesis. The patient's plasma was cytotoxic for erythroblasts. Following splenectomy, a remission of the disease occurred. This study indicates that in some cases the anemia associated with abundant marrow proerythroblasts and the absence of mature erythroblasts has the same pathogenesis as pure red cell aplasia and that splenectomy may be beneficial when there is a lack of response to immunosuppressive drugs.
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PMID:Studies on pure red cell aplasia. VII. Presence of proerythroblasts and response to splenectomy: a case report. 113 41

Splenomegaly accompanied by anaemia, increased reticulocyte and decreased thrombocyte counts, was induced in Wistar rats by a long-term intraperitoneal administration of methylcellulose. Compared to controls, hypersplenic rats showed significantly enhanced utilization of 59-Fe by red cells and increased titre of erythropoietin. After the exposure of rats to hypoxic hypoxia corresponding to an altitude of 7,000 m for 6 h, no difference in the erythropoietin titre was found in either group. The results suggest that experimental hypersplenism alone does not affect the production of erythropoietin and does not stimulate the formation of an inhibitor of erythropoietin or erythropoiesis. The increased titre of erythropoietin and enhanced utilization of radioiron by red cells in rats with hypersplenism were found to be due to haemolytic anaemia leading to the stimulation of erythropoiesis.
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PMID:Erythropoietin formation in rats with experimental hypersplenism. 114 16

A highly purified erythropoietin (ESF) preparation (12,000 units per milligram of protein) was labeled with Na'125I using the Chloramine-T method. Undamaged immunoreative labeled ESF was separated from the damaged, nonimmunologically receiveESF by Sephadex G-150 fractionation. This undamaged immunreactive ESF was usedin radioimmunoassay for human erythropoietin. Separation of bound from free antigen was acheived using the double-antibody technique. Approximately 55 per cent binding wasobserved at an antiserum dilution of 1:1500. This assay appears to be sensitive enough to detect as little as 0.025 milliunits of the International Reference Preparation erythropoietin. The estimated levels of thid hormone in normal and anemic uremic human subjects suggests that immunoreactive serum erythropoietin levels are elevated above normal in anemia of uremia.
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PMID:Studies on a radioimmunoassay for human erythopoietin. 115 Nov 36

The effect of phenylhydrazine (PHZ) on the hematopoietic events in the embryonic spleen of C57Bl/6J mice was examined by light and electron microscopy. Following PHZ in injections to the mothers, the embryonic spleen revealed a marked increase in erythroid precursors, with a shift to mature cells. This phenomenon was part of a more generalized stimulation of erythorpoiesis, expressed by a shift to mature red cell precursors in the embryonic livers and an increase in the percentage of non-nucleated cells in the embryonic peripheral blood. Concomitantly stimulation of phagocytosis in the spleen of embryos in the early gestational days and increased vascularity were observed, and a later effect of granulocytopoietic stimulation. The effect on erythropoiesis in the embryonic spleen might be a sequence of erythropoietin stimulation, either in the mothers or the fetuses, due to anemia and hypoxia following PHZ injections.
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PMID:Hematopoiesis in the embryonic mouse spleen. II. Alterations after phenylhydrazine administration to the mothers. 115 87

Bone marrow cells of patients with chronic renal failure were studied in short-term in vitro cultures to determine erythropietin responsiveness. Seven normals and fourtheen patients on hemodialysis were studied. Bone marrow cells of normal subjects and of patients with chronic renal failure responded similarly to erythropoietin. Total heme synthesis was significantly lower in cultures prepared with uremic serum than normal serum. We conclude that there is a substance in the serum of uremic patients which suppresses general heme synthesis and that this "uremic toxin" may be responsible, in part, for the clinically severe anemia seen in these patients.
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PMID:The anemia of chronic renal failure: in vitro response of bone marrow to erythropoietin. 116 90

Anemia is known as one of the earliest manifestations of chronic renal insufficiency. Anemia begins at a serum creatinine level of 2 mg/100 ml. There is no correlation between the degree of anemia and the etiology of renal disease. Patients on chronic hemodialysis shown an average hematocrit of 23%. In the pathogenesis of renal anemia various factors may be discussed, especially a deficiency of iron and erythropoietin. A method of conservative therapy which would allow optimal treatment of renal anemia is not yet available. Successful renal transplantation has to be considered the best therapeutic measure in terminal renal insufficiency.
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PMID:[Anemia in chronic renal insufficiency]. 119 26


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