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)

Pre- and post-transplant bone marrow samples from 20 patients with aplastic anemia were studied. Morphologic evidence of marrow reconstitution was noted in 18 patients one to three weeks following transplantation. In most instances the engrafted marrow elements in early weeks appeared as small clusters of erythroid or myeloid precursors. Bone marrow biopsy or clot sections obtained four to eight weeks after transplantation were more cellular with larger clusters of hematopoietic cells, which were most often composed of mixed cellular elements, including megakaryocytes. Two patients with morphologic evidence of engraftment died shortly after transplantation and were excluded from further analysis. In four of the remaining 16 patients grafts were "rejected" three to eight weeks after transplant. A fifth patient who received a marrow graft from his identical twin showed a transient increase in marrow cellularity without clinical improvement. However, the second marrow transplantation in this patient using the same donor after conditioning with cyclophosphamide resulted in moderate clinical improvement. In four of the five patients developing graft "rejection" or failure there was an increase in marrow mast cells in pre- and post-transplant marrow samples. In contrast, only two of 11 patients with successful engraftment had an increase in mast cells. Although the pathophysiologic role of mast cells in marrow transplantation is unclear, the present study suggests a possible inverse correlation between the numbers of marrow mast cells and the likelihood of successful engraftment. Bone marrow samples in patients with graft versus host disease displayed a slight increase in the number of eosinophils, lymphocytes, and plasma cells.
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PMID:Morphologic aspects of bone marrow transplantation in patients with aplastic anemia. 2 34

Fetal erythropoiesis occurs during chronic bone marrow failure, or during recovery from marrow suppression. Fetal erythrocytes have HB F, with more G gamma than A gamma chains, "i" antigen, large MCV, characteristic enzyme levels, low carbonic anhydrase, low HB A2, and short life span. Many of these fetal characteristics are present in the red cells of patients with temporary or chronic hematopoietic stress. In those in whom normal hematopoiesis ensues, the fetal erythrocytes disappear. The fetal phase of recovery may be with homologous stem cells after bone marrow engraftment, or with autologous cells. Chronic fetal erythropoiesis is seen in patients with constitutional aplastic anemia, such as Fanconi's anemia or Diamond-Blackfan anemia. In one patient with the latter disorder, fetal erythropoiesis accompanied chronic anemia, and actually decreased slightly during the acute phase of clinical improvement. Culture of late erythroid precursor cells (CFU-Es) from a patient with transient erythroblastopenia of childhood led to in vitro development of colonies with HB F, an event not seen in normal marrow cultures. Thus fetal erythropoiesis occurs during hematopoietic stress, whether chronic or transient, if there is some marrow activity, and may be due to expansion of fetal clones.
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PMID:Fetal erythropoiesis in stress hematopoiesis. 9 16

Bone marrow biopsies (244) performed with a Jamshidi needle were evaluated in 53 children with leukemia or aplastic anemia. Adequate specimens were obtained in 85%. Results of cellularity estimated by biopsy were compared to the cellularity of the aspirate versus volumetric determination of the myeloid-erythroid layer (buffy coat). A wide discrepancy was noted between marrow cellularity confirmed by biopsy versus the aspirate or buffy coat. The greatest variance was seen in the hypercellular or normocellular marrows, as estimated by biopsy, in which 39% were misinterpreted as moderately or severely hypocellular by aspirate. Volumetric measurement of buffy coat was least acceptable for estimating cellularity. Thus the biopsy has proved to be an important and reliable indicator of bone marrow cellularity.
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PMID:Bone marrow cellularity determination: comparison of the biopsy, aspirate, and buffy coat. 26 73

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

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

One hundred and twenty-nine Chinese patients with aplastic anaemia, were studied. In ten it was induced by drugs, one followed hepatitis and the remainder were of unkown cause. Mortality within the first six months was 47.3 per cent. Features associated with poor prognosis included a short duration of symptoms of three months or less, neutropenia of less than 0.5 x 10(9)/l and severe thrombocytopenia. On the other hand, some preservation of erythroid activity of the bone marrow was associated with long survival. Remission occurred in 47 patients and this was associated with androgen therapy in 33. Remission was complete in 18 and partial in 29. In the latter group, persistent thrombocytopenia was the main abnormality and treatment with calusterone led to an increase in platelets although the effect was not sustained after its withdrawal. Hepatotoxicity was seen in 16.0 per cent of patients treated with androgens and this occurred even with non-17alpha-alkylated compounds. It is concluded that androgen therapy was useful and should be started as early as possible after diagnosis. Hepatic intolerance to androgens may be an indication for bone marrow transplantation.
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PMID:Aplastic anaemia: a study of prognosis and the effect of androgen therapy. 59

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

In 11 patients with megaloblastic anemia, transfusion of packed erythrocytes or washed erythrocytes invariably resulted in a decline in plasma iron concentration to a range of 20-90 microgram/dl (3.6-16 mumol/l) after 36 to 48 hours. The same phenomenon was observed in two of six cases of ineffective erythropoiesis without megaloblastosis and in none of five cases of aplastic anemia. The observed changes did not result from a specific hematinic response or from iron uptake by a non-erythroid compartment. In megaloblastic anemia, alteration in marrow function in response to transfusion was reflected by plasma iron kinetics and serum lactate dehydrogenase values, which indicated marked reductions in both marrow hyperplasia and ineffective erythropoiesis. Transfusion in megalobastic anemia was also responsible for a 50% reduction in platelet count after 2 to 6 days. The significance of these changes is discussed.
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PMID:Effects of transfusion on serum iron, serum lactate dehydrogenase and platelets in megaloblastic anemia. 90 75

The cell composition of peripheral blood, bone marrow and spleen of CBA mice after the transplantation ca. 20.10(6) lymph node cells of a Wistar rat, sensitized against mouse liver antigens 10--15 days prior to the transplantation, during first 24 hrs after birth was studied. The runt disease developed in 100% recipients and was characterized by sharp disturbances of the formation of immuno- and hemopoietic systems. All runting animals suffered from aplastic anemia, leukopenia with predominance of hyperlobular neutrophils and histio-monocytes in the peripheral blood. The total number of cells in bone marrow decreased almost 15 times. The elimination of erythroid line was coupled with relative augmentation of undifferentiated myeloid and monocytoid cells. The cellular pool of spleen increased twice and more. The intensive proliferation of histio-monocytes and macrophages was accompanied by the destruction and depletion of lymphatic structures. A suggestion is put forward to the effect that the incorporation of "not-self" genetic information, such as non-syngeneic lymphocytes, during the early postnatal period may not only induced some genuine immunological effects, but inhibit the normal way of differentiation in proliferating cell systems due to the lack of their mutual adaptation as well.
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PMID:[Disorders in the formation of the hematologic status of mice following rat lymph node transplantation during the early postnatal period]. 105 39


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