Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026986 (myelodysplastic syndrome)
 14,926 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An increasing amount of data provides strong evidence for the complex multifactorial control of primary hemopoietic functions. Here we present a new multicellular functional unit, the Hematon, isolated from the light-density floating fraction of normal human bone marrow (BM) aspirates. The Hematon is organized in a compact, three-dimensional spheroid complex from central adipocytes, fibroblastoid cells, and resident macrophages that compartmentalize myeloid, erythroid, and megakaryocyte progenitor cells and their progenies. The Hematon fraction is more than twofold more abundant in progenitor cells when compared to the mononuclear cell (MNC) fraction as gauged by cytological techniques and by analysis of granulocyte-macrophage colony-forming unit (GM-CFU) populations. Individual Hematons may produce, within 2-3 weeks, up to 50,000 hemopoietic cells of different cell lineages in organotypic microcultures. Recombinant human hematopoietic growth factors interleukin 3 (IL-3), granulocyte-macrophage colony-stimulating factor (GM-CSF), granulocyte colony-stimulating factor (G-CSF), and macrophage colony-stimulating factor (M-CSF) significantly stimulated the endogenous cell production of some but not all of the individually treated Hematons, indicating the heterogeneity of factor-responsive cells within the Hematon population. Comparative observations of 184 BM aspirates support the hypothesis that the presence of Hematons in a BM aspirate correlates positively with homeostatic blood cell production, because the Hematon was present in normal BM (31/40) and it was rare among patients with myelodysplastic syndromes (15/53), acute myeloblastic leukemia (7/39), and chronic myelocytic leukemia (5/52). We suggest that the Hematon represents a unifying model around which the variability of fundamental BM functions and dysfunctions can be explored.
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PMID:Hematon, a multicellular functional unit in normal human bone marrow: structural organization, hemopoietic activity, and its relationship to myelodysplasia and myeloid leukemias. 218 30

DNA samples from 76 patients with the myelodysplastic syndromes, including 10 cases with a partial deletion of the long arm of chromosome 5 (5q-), were examined for structural rearrangements of the granulocyte/macrophage colony-stimulating factor (GM-CSF) gene. No abnormalities were detected, indicating that structural aberrations of this gene are not a feature of the myelodysplastic syndromes.
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PMID:Structure of the granulocyte macrophage colony-stimulating factor gene in patients with the myelodysplastic syndromes. 198 90

The major hematopoietic growth factors have been produced through recombinant DNA technology and have entered initial clinical trials; results of these trials will be reviewed here. Granulocyte colony-stimulating factor (G-CSF) has been tested in patients with bladder cancer and small-cell carcinoma of the lung. In these studies, G-CSF ameliorated the leukopenia associated with combination chemotherapy, reduced the incidence of mucositis in the bladder cancer patients, and nearly eliminated the occurrence of serious infections in the lung cancer patients. Trials involving another factor, granulocyte macrophage colony-stimulating factor (GM-CSF), have resulted in a marked increase in white blood cell (WBC) counts in patients with myelodysplastic syndromes, and has accelerated the appearance of leukocytes and platelets after autologous bone marrow transplants. GM-CSF can also increase the WBC counts in acquired immunodeficiency syndrome patients treated with zidovudine. Both G-CSF and GM-CSF may produce multilineage effects in certain clinical settings and dose ranges. Finally, interleukin-1 (IL-1) and IL-3, which commit very early stem cells to a myeloid pathway, may be used in combination with G-CSF or GM-CSF to produce a synergistic response to various clinical situations.
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PMID:Status of colony-stimulating factors in cancer and AIDS. 240 93

The FMS gene encodes the functional cell surface receptor for colony-stimulating factor 1, the macrophage- and monocyte-specific growth factor. Codons 969 and 301 have been identified as potentially involved in promoting the transforming activity of FMS. Mutations at codon 301 are believed to lead to neoplastic transformation by ligand independence and constitutive tyrosine kinase activity of the receptor. The tyrosine residue at codon 969 has been shown to be involved in a negative regulatory activity, which is disrupted by amino acid substitutions. This study reports on the frequency of point mutations at these codons, in vivo, in human myeloid malignancies and in normal subjects. We studied 110 patients [67 with myelodysplasia (MDS) and 48 with acute myeloblastic leukemia (AML)], 5 patients being studied at the MDS and the later AML stage of the disease. There was a total incidence of 12.7% (14/110) with mutations in codon 969 and 1.8% (2/110) with mutations in codon 301. Two patients had mutations in the AML stage of the disease but not in the preceding MDS and one had a mutation in the MDS stage but not upon transformation of AML. This is consistent with the somatic origin of these mutations. FMS mutations were most prevalent (20%) in chronic myelomonocytic leukemia and AML type M4 (23%), both of which are characterized by monocytic differentiation. One of 51 normal subjects had a constitutional codon 969 mutation, which may represent a marker for predisposition to myeloid malignancy.
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PMID:FMS mutations in myelodysplastic, leukemic, and normal subjects. 240 20

A number of cloned biologic factors are currently available that are candidates for therapy of myelodysplastic syndromes and, by extension, acute nonlymphoblastic leukemia. gamma-Interferon and, to a greater extent, tumor necrosis factor exhibit leukemic differentiative effects without the potential for stimulation of leukemic clones. These effects may be enhanced by combinations of these with one another or with chemical inducers of differentiation such as retinoic acid or vitamin D derivatives. The colony-stimulating factors clearly have potent in vivo effects upon hematopoiesis. The lineage specific factors (G- or M-CSF) may have greater differentiation induction potential and less risk of accelerating emergence of leukemic clones than the earlier acting factors (GM- or multi-CSF). Thus, several potentially fruitful avenues for clinical research are currently available.
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PMID:The basis for treatment of myelodysplastic syndrome and acute nonlymphoblastic leukemia with biologic agents. 245 61

[3H]thymidine uptake by NFS-60 cells in microcultures was found to increase in a linear fashion with the increasing doses of purified recombinant human granulocyte colony-stimulating factor (rhG-CSF). Such increases were found neither with rhG-CSF samples pretreated with rabbit anti-rhG-CSF serum nor with other human colony-stimulating factors such as granulocyte-macrophage colony-stimulating factor (hGM-CSF) or macrophage colony-stimulating factor (hM-CSF). Based on these findings, sera from normal persons and patients with severe infections or various hematological disorders were tested after dialysis using this system in order to determine whether G-CSF levels in sera can be estimated or not. In ten normal persons, five patients with acute myelogenous leukemia (AML M1, M2, and M3), five with myelodysplastic syndrome, and four with chronic myelogenous leukemia, no increases in [3H]thymidine uptake were found within the dose range of 0.4 microliters to 50 microliters. In contrast, linear dose responses parallel to a G-CSF standard curve were observed in one patient with a severe bacterial infection, four with aplastic anemia, two with acute myelomonocytic leukemia (AMMoL) (M4), and two with idiopathic neutropenia tested. From the standard curve, the probable levels of G-CSF were calculated as follows: approximately 200 pg/ml with infection, 130-220 pg/ml with aplastic anemia, 150 and 200 pg/ml with AMMoL, and 1120 and 1200 pg/ml with idiopathic neutropenia. The activities of sera were reduced by the anti-rhG-CSF serum pretreatment in the same way as documented in the case of rhG-CSF. Furthermore, the level in a patient with a severe infection became undetectable soon after elimination of the infection and blood neutrophil counts had returned to normal. These findings indicate that the microbioassay system will be useful for measuring circulating G-CSF levels which would fluctuate in accord with requirements for stimulating neutrophil production or with abnormal production of hG-CSF.
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PMID:A new bioassay for human granulocyte colony-stimulating factor (hG-CSF) using murine myeloblastic NFS-60 cells as targets and estimation of its levels in sera from normal healthy persons and patients with infectious and hematological disorders. 246 30

The myeloid growth factors are a promising new class of therapeutic agents with the potential for broad clinical application. Four recombinant myeloid growth factors, granulocyte macrophage colony-stimulating factor (GM-CSF), granulocyte colony-stimulating factor (G-CSF), macrophage colony-stimulating factor (M-CSF), and interleukin (IL)-3 are available for clinical trials. GM-CSF has been studied in leukopenia related to acquired immunodeficiency syndrome (AIDS), aplastic anemia, and myelodysplasia, as well as in patients receiving chemotherapy and those undergoing autologous bone marrow transplantation. In these trials, GM-CSF was demonstrated to increase the number of neutrophils, eosinophils, and monocytes with corresponding bone marrow changes. Toxicity is dose-related, and maximum tolerated dosages are in the range of 16 to 32 micrograms/kg/day. The effects of daily subcutaneous administration of GM-CSF appear to be similar to those of intravenous (IV) administration. G-CSF, studied mainly in the treatment of neutropenia following cytotoxic chemotherapy, was found to decrease the duration of severe neutropenia as well as the risk of infections. G-CSF causes prominent increases in neutrophil levels without affecting eosinophils or monocytes. Associated toxicity is minimal, and subcutaneous administration is efficacious. Preliminary evidence suggests that G-CSF may also have a therapeutic role in indolent lymphoid neoplasms complicated by neutropenia. Administration of natural M-CSF to patients receiving chemotherapy and those with chronic childhood neutropenia has shown modest neutrophil increases. Preclinical data on IL-3 suggest that this agent increases neutrophils, eosinophils, basophils, reticulocytes, and possibly platelets.
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PMID:Clinical applications of the myeloid growth factors. 247 Dec 74

Recombinant DNA technology has allowed for the production of large quantities of several hematopoietic growth factors as cloned gene products. Three of these factors--recombinant human erythropoietin (r-HuEPO), granulocyte macrophage colony-stimulating factor (GM-CSF), and granulocyte colony-stimulating factor (G-CSF)--are currently undergoing clinical trials and appear to offer considerable promise for the treatment of a variety of hematopoietic abnormalities. Therapy with r-HuEPO can raise the hematocrit levels of patients with end-stage renal disease. Therapy with GM-CSF in patients undergoing marrow transplantation results in acceleration of granulocyte and platelet recovery by 1 to 2 weeks, leading to fewer infections and earlier discharge from the hospital. Other demonstrated uses of GM-CSF include treatment for aplastic anemia, myelodysplastic syndromes, chemotherapy-induced neutropenia, and neutropenia associated with the acquired immunodeficiency syndrome (AIDS). Similar beneficial effects have been reported with G-CSF. Other hematopoietic growth factors, including the interleukins (IL)-1, -3, and -6, will soon be entering clinical trials. For the first time, the availability of a large number of hematopoietic growth factors may allow physicians to regulate closely the entire hematopoietic system of their patients.
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PMID:The clinical use of hematopoietic growth factors. 247 5

Regulation of haemopoiesis in the marrow of patients with myelodysplastic syndromes (MDS) was evaluated by assaying (1) the production of haemopoietic regulators acting upon multipotent and committed progenitors by MDS marrow cells, and (2) the responsiveness of MDS marrow progenitors to stimulation with granulocyte colony-stimulating factor (G-CSF). The levels of multipotent progenitor cell colony-stimulating activity (CFU-GEMMCSA) in 7 d bone marrow-conditioned medium (BMCM) from MDS patients were markedly reduced as compared to controls. MDS BMCM also exhibited reduced levels of burst-promoting activity (BPA) for primitive erythroid (BFU-E) progenitors. Both CFU-GEMMCSA and BPA detected in BMCM were completely neutralized by antibodies directed against interleukin-3. MDS BMCM exhibited markedly reduced levels of murine-active CSA. This activity was partially neutralized by anti-CSF-1 antibodies. Levels of regulators in BMCM of refractory anaemia (RA), sideroblastic anaemia. RA with excess blasts, and chronic myelomonocyte leukaemia were virtually the same. CFU-GEMM and BFU-E growth in MDS marrow (n = 9) was markedly reduced. A 5-fold saturating dose of G-CSF induced an approximately 2-fold increase in CFU-GEMM in four of eight MDS and a 1.5-fold increase of BFU-E in five of nine MDS, but not in control (n = 5) marrow cell cultures. Impaired haemopoiesis in MDS marrow may be related to abnormalities both in regulator production by marrow accessory cells and in regulator responsiveness of multipotent and committed progenitors.
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PMID:Regulatory abnormalities in the marrow of patients with myelodysplastic syndromes. 247 8

Five glycoprotein growth factors capable of stimulating the proliferation and differentiation of haemopoietic progenitor cells in vitro have been identified and sequenced over the past ten years. Recombinant DNA technology has recently enabled the production of sufficient amounts of these agents for preclinical testing. Erythropoietin (EPO), granulocyte-macrophage colony-stimulating factor (GM-CSF), and granulocyte colony-stimulating factor (G-CSF) have already entered clinical studies in humans. Interleukin-3 (IL-3) and macrophage colony-stimulating factor (M-CSF) should soon be available for use in humans. EPO corrects the anaemia of end stage renal failure, improving the quality of life for such patients and preventing the need for red cell transfusions. At high dose it increases platelet production in vitro and in vivo and may be of value in humans to prevent the thrombocytopaenia associated with chemotherapy. G-CSF and GM-CSF have been used in several clinical studies. Administration of both growth factors results in a leucocytosis, G-CSF predominantly increasing neutrophil production and GM-CSF increasing production of neutrophils, eosinophils and monocytes. The optimal administration of these agents is via continuous intravenous infusion or daily subcutaneous injections at doses of 3-10 micrograms/kg/24 h. GM-CSF has shown promising results in patients with AIDS and the myelodysplastic syndrome and both G-CSF and GM-CSF have reduced the duration of neutropaenia and incidence of infection associated with chemotherapy. These agents may allow an escalation of the dose-intensity of chemotherapy in the future and thereby, hopefully, increase the response rate and survival for patients with a variety of neoplasms. Several other potential roles for these haemopoietic growth factors are discussed.
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PMID:Clinical trials with haemopoietic growth factors. 249 Dec 51


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