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)

C57BL mice inoculated with radiation leukemia virus (RadLV) develop preleukemic cells long before the onset of leukemia. These cells are potentially immunogenic but fail to elicit an immune response in the host because of the appearance of virus-specific suppressor T cells. We have studied the effect of polysaccharide K (PSK) on the generation of RadLV-specific cell-mediated immune responses in vitro. Long-term exposure to PSK in culture potentiated the ability of immunized T cells to respond to a RadLV-induced lymphoma. It also abrogated the suppressive activity of suppressor T cells and simultaneously boosted the ability of reactive T cells to respond. The dual immunostimulating activity of PSK resulted in the generation of T cytotoxic lymphocytes that could lyse lymphoma cells in vitro. The results suggest that PSK could be used as a prophylactic immune response modifier in preleukemia.
Cancer Immunol Immunother 1991
PMID:Potentiation of T cell immunity against radiation-leukemia-virus-induced lymphoma by polysaccharide K. 176 Aug 17

C-myc expression was studied semi-quantitatively in bone marrow biopsies obtained from normal individuals, patients with non-malignant haematological disorders and patients with various haematological malignancies. In normal bone marrow and in the bone marrow of patients with non-malignant haematological disorders, cells containing c-myc protein are present in small clones (average 7 +/- 2.5 cells/clone) located in the centre of the histotopographic region of the biopsy. In contrast, c-myc-containing cells are diffusely distributed in the bone marrow of patients with acute myelogenous leukaemia (AML). In the marrow of patients with myelodysplastic syndromes evolving to AML and in patients with AML in early relapse, the clones of cells containing c-myc are larger than those present in normal marrows (average clone size = 17.5 +/- 3.5 cells). Additionally, the proportion of the cells in normal bone marrow which express c-myc protein is less than that present in AML marrows (23.3 +/- 10.17 v. 60.2 +/- 6.17) and the intensity of staining is also less. Non-Hodgkin's lymphoma patients with bone marrow involvement had distribution of c-myc positive cells similar to those with leukaemic infiltration.
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PMID:Studies of the geographic patterns of c-myc expression in bone marrow. 176 35

The activity of microsomal HMG-CoA reductase in freshly isolated leukocytes from patients with a variety of hematologic malignancies was significantly increased (up to 20-fold) when compared to enzyme activity in leukocytes from normal subjects (average 10.3 +/- 0.8 pmol/min per mg). Increased enzyme activity was not due to nonspecific leukocyte stimulation or to the presence of a malignancy, since normal enzyme activity was observed in subjects with either viral illnesses or solid tumors. Increased HMG-CoA reductase activity accompanying hematologic malignancy could also not be attributed to alterations in enzyme-substrate kinetic parameters (Km), or to alterations in the phosphorylation state or thiol-disulfide status of the enzyme, nor was it correlated with differences in serum lipid or lipoprotein concentrations. The increase (3.6-fold) in HMG-CoA reductase activity in leukocytes from patients with preleukemia was due entirely to a rise in enzyme catalytic efficiency (specific activity), whereas the increase (4.3-fold) observed in leukocytes from patients with overt leukemia or non-Hodgkin's lymphoma was due to a concomitant increase in both enzyme catalytic efficiency (2.5-fold) and enzyme protein concentration (1.6-fold). Similar increases in HMG-CoA reductase activity and catalytic efficiency were also noted for both transformed, nonmalignant, and malignant cultured leukocytes, suggesting that increased enzyme catalytic efficiency is not a nonspecific consequence of physiological changes occurring in response to the malignancy but may be an integral aspect of the malignant phenotype. HMG-CoA reductase protein concentrations, however, were not elevated in either transformed, nonmalignant, or malignant cultured leukocytes, suggesting that increases in enzyme protein levels may be secondary to other physiological changes that occur during the development of overt leukemia. Taken together, these observations suggest that an increase in the activity of HMG-CoA reductase, the rate-controlling enzyme in cholesterol synthesis, is a common occurrence in human hematologic malignancies and that a biphasic elevation of enzyme activity may exist in malignant leukocytes, such that changes in catalytic activity may occur early in tumorigenesis and may be followed by secondary changes in enzyme levels.
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PMID:In vivo regulation of human leukocyte 3-hydroxy-3-methylglutaryl coenzyme A reductase: increased enzyme protein concentration and catalytic efficiency in human leukemia and lymphoma. 177 Mar 7

Evidence has been presented for two potential methods of administering lipid A derivatives for the reduction of endotoxicity: 1. Use of low doses of agonists to induce early-phase tolerance for a sufficiently long period to protect patients at risk of endotoxin shock. 2. Administration of high doses of antagonists to the LPS-induced release of proinflammatory cytokines. The strengths and weaknesses of both approaches can be summarized as follows: Approach 1 appears promising for patients at risk for septicemias, based on iatrogenic induction of neutropenias or genetically caused neutropenic states, e.g., in cancer patients receiving aggressive chemotherapy or irradiation and in patients receiving immunosuppressive therapy (transplantations, myelodysplastic syndromes, and so forth.) Strengths. A long lasting effect can be expected. Broad protection against many types of infectious organisms. Strong potentiation of antibiotic chemotherapy anticipated irrespective of resistance patterns to antibiotics. Weaknesses. Only prophylactic treatment appears possible. Potential for endotoxic side-effects remains. Approach 2, the administration of LPS antagonists, appears most promising in clinical situations when interference with acute endotoxic shock symptoms subsequent to polytrauma is necessary. Strengths. Immediate onset of activity would be expected. Lower risk of side-effects. Weaknesses. Therapy may already be too late. Activity is restricted to endotoxicity, there being no anti-infectious potential. High drug levels might be required for a prolonged period. Synergism with antibiotics is not yet established. Together, these new lipid A derivatives open up new potential therapeutic avenues for the prophylaxis and therapy of septic shock, septicemias, and infections. Clinical studies will soon show whether the exciting pharmacologic effects observed in animals can be translated into humans.
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PMID:Lipid A analogs aimed at preventing the detrimental effects of endotoxin. 178 72

Erythropoietin is a glycoprotein hormone that plays a vital role in erythropoiesis. It is mainly produced in the fetal liver till the third trimester of pregnancy. At that point, the kidney interstitium takes over this function and becomes the main source of erythropoietin. Hypoxia stimulates erythropoietin production by a mechanism that may require a heme protein as a second messenger. Erythropoietin stimulates the maturation of erythroid precursors (colony-forming unit-erythroid and burst-forming unit-erythroid) via at least two types of cell surface receptors. The higher-affinity receptors appear to be more important in modulating the effects of erythropoietin in vivo. Changes in intracellular calcium may ultimately mediate the action of erythropoietin on erythroid precursors. A specific and sensitive radioimmunoassay is now available for accurately measuring erythropoietin levels. All forms of erythrocytosis except polycythemia vera are associated with elevated erythropoietin levels. Levels are also high in cord blood obtained following fetal asphyxia. Reduced levels are seen in patients with anemia due to renal diseases. The response of erythropoietin to the degree of anemia appears to be attenuated in patients with cancer, chronic diseases, and human immunodeficiency virus (HIV) infection. Erythropoietin has been successfully used for treating patients with anemia due to renal failure. Its use has also been approved for the treatment of anemia patients receiving zidovudine for HIV infection. Encouraging results have been observed when erythropoietin was used to treat anemia due to rheumatoid arthritis, hematological malignancies, and prematurity. It has also been used to increase the yield of autologous blood collected prior to an elective surgical procedure. However, it has not proved to be useful in sickle cell anemia and myelodysplastic syndromes.
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PMID:Erythropoietin. Biology and clinical applications. 178 66

The human recombinant GM-CSF (hrGM-CSF) is a glycosylated hematopoietic growth factor, derived from CHO cells (Schering Plough/Sandoz) used in these studies. The hrGM-CSF can be given intravenously (i.v.) in 4- to 24-h infusions or subcutaneously (scx) once or twice a day. Many patients (more than a thousand) have been treated with the hrGM-CSF in various pathologies, in association with anti-cancer chemotherapy, after bone marrow transplants or for myelodysplasias, refractory anemias, some neutropenias and infections. The reversion of neutropenia is dose-dependent with either a sc or i.v. administration. Recommended doses are from 5.0 to 10.0 micrograms/kg/per day. When the product is given sc the effect is delayed by one day but is more prolonged than with the i.v. route. The treatment duration has been investigated in different studies: a minimal duration of 5 days seems appropriate. When given in association with high doses of cytotoxic chemotherapeutic agents 10 to 14 days are required. In bone marrow transplants (autologous or allogenic with T-cell depletion), the hrGM-CSF has been shown to significantly reduce the time necessary for engraftment. Contrary to some fears, it was not shown that hrGM-CSF increased the risk of blastic transformation in myelodysplastic syndromes. In association with cytosine-arabinoside a certain number of partial and complete responses have been obtained. The toxic effects of the product are also dose-dependent. At doses greater than 11 micrograms/kg per day, there is a risk of stimulating inflammatory phenomena whereas at lower doses, more moderate side effects (myalgia, fever, injection site reaction) occur in only 30% of the cases. The GM-CSF will certainly be important in the future in haematology, oncology and for the treatment of infectious diseases.
Bull Cancer 1991
PMID:Recombinant human GM-CSF: present clinical results and potential use in oncologic and hematologic disorders. 178 28

Recombinant human granulocyte macrophage colony-stimulating factor (rhGM-CSF) was one of the first of the myeloid growth factors to become available for clinical trials. Phase I studies have demonstrated that the optimal administration is by continuous intravenous infusion or subcutaneous injections at doses of 4-5 micrograms/kg/day. Phase II trials in patients with a variety of malignancies who receive rhGM-CSF after standard doses of chemotherapy have demonstrated significant reductions of the duration of leucocytopenia. Use of rhGM-CSF after high-dose chemotherapy (with or without bone marrow rescue) suggest that this agent decreases the time to recovery of a normal blood count and reduces infective complications. Results in myelodysplasia and aplastic anemia have been less encouraging. The potential value of rhGM-CSF in the treatment of a variety of other conditions including AIDS and the leukemias is being tested and the early results are discussed.
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PMID:Recombinant human granulocyte macrophage colony-stimulating factor: current status of clinical trials and potential future applications. 179 89

Three children, two boys and one girl, with Down syndrome (DS) who presented with preleukemia and loss of all or part of chromosome 7 were studied. Initial presentation, with cytopenias and less than 25% blasts in the bone marrow, was between 13 and 30 months of age. Progression to acute nonlymphocytic leukemia occurred 1-8 months after initial presentation. The morphologic type was megakaryoblastic in two, and undifferentiated in one. Two children achieved remission with intensive therapy, and one continues in remission off therapy; the other child died in remission of accidental causes. The third child died of respiratory distress and leukemia after no intervention was chosen. These cases represent the first examples of chromosome 7 abnormalities associated with DS and leukemia, and suggest differences from the "monosomy 7" syndrome seen in children without DS.
Cancer Genet Cytogenet 1991 Jul 01
PMID:Chromosome 7 abnormalities in children with Down syndrome and preleukemia. 182 46

14 patients with acute myeloid leukaemia (AML) and 7 with myelodysplastic syndrome (MDS) were treated with cytarabine in low dosage. In AML a complete remission rate of 43% was found and in all patients profound cytopenia was noticed without any sign of maturation induction. In MDS no effect of low-dose cytarabine could be detected. We also studied the effect of low-dose cytarabine in vitro in freshly isolated leukaemic cells of 10 patients with AML. Maturation induction was measured by a comprehensive panel of quantitative and qualitative markers of maturation. No differentiation inducing effect of low-dose cytarabine could be found. We conclude on the basis of our own results and after reviewing the literature that low-dose cytarabine exerts its effect by cytotoxicity instead of maturation induction.
Eur J Cancer 1991
PMID:Low-dose cytarabine for acute myeloid leukaemia and myelodysplastic syndromes: in vivo and in vitro cytotoxicity. 183 14

In human cancer, lysosomal hydrolases contain increased amounts of phosphorylated sugar chains. Sugar chains of the hydrolases undergo post-translational processing which is catalyzed by N-acetylglucosamine-1-phosphotransferase (GlcNAc-phosphotransferase) at the first step. In the present study we estimated serum GlcNAc-phosphotransferase in 50 adults suffering from leukemia and myelodysplastic syndrome. The serum GlcNAc-phosphotransferase was increased to moderate or high levels in patients with acute nonlymphocytic leukemia (ANLL), acute lymphoblastic leukemia and chronic myelogenous leukemia, suggesting that the serum transferase is released from leukemic cells. In many cases of ANLL examined, activity of the transferase was decreased concomitantly with reduction of peripheral blastic cells by effective chemotherapy.
Jpn J Cancer Res 1991 Jan
PMID:Increased N-acetylglucosamine-1-phosphotransferase activity in sera from patients with leukemia. 184 3


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