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)

Peripheral cytopenias are common in patients with myelodysplastic syndromes. We previously successfully treated three such patients with improvement of some cytopenias with the impeded androgen danazol. To confirm this finding and elucidate the mechanism of response, we treated an additional 22 patients with myelodysplasia with oral danazol (600-800 mg daily) for 3-12 months. Eleven of 22 evaluable patients taking danazol met our criteria for improvement of peripheral counts, mainly thrombocytopenia. Chromosome analysis, marrow culture studies and serial bone marrow biopsies revealed no alteration of the abnormal clone or normal haematopoiesis in patients on danazol therapy. This suggested that improvement in blood counts was not related to modulation of ineffective haematopoiesis. Investigation of the thrombocytopenia in these patients revealed that most patients presented with markedly elevated platelet associated IgG (PAIgG), elevated plasma platelet-bindable IgG (PBIgG), and an elevated number of monocyte Fc gamma receptors. Treatment with danazol was associated with a decline in monocyte Fc gamma receptor number without significantly altering the elevated PAIgG or PBIgG levels. These results are similar to our observations in patients treated with danazol for chronic idiopathic thrombocytopenia purpura (ITP). Our data suggest that a component of the thrombocytopenia occurring in patients with myelodysplasia may be due to enhanced peripheral blood cell destruction by abnormal macrophages. Danazol may modulate cytopenia by decreasing the number of monocyte Fc gamma receptors. Danazol treatment was associated with minimal toxicity, but clinically meaningful responses were rare.
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PMID:Danazol treatment of myelodysplastic syndromes. 825 1

A novel human cultured cell line, P39/Tsugane, was established from leukemic cells in the peripheral blood of a 69-year-old male with overt leukemia following myelodysplastic syndrome (MDS). P39/Tsugane cells were characterized by blastic appearance, presence of NaF-sensitive alpha-naphthyl butylate esterase activity, Fc gamma-receptor, C3-receptor, capacity to phagocytize sensitized erythrocytes, and reactivity with monoclonal antibodies such as OKT4, My4, VIMD5, MCS-2 and My7. These data indicate that P39/Tsugane cells are of myelomonocytoid nature. P39/Tsugane had a hypodiploid chromosome constitution with a gain of a consistent marker, 6q+, the presence of less consistent markers 9q+ and rcp(14;16), and random and non-random losses of autosomes: in accordance with the reported cytogenetic profiles of MDS, a representative karyotype of the present cell line is 45,XY,+del(6)(q15),9q+, t(14;16)-(q24;q21),-16,-17. P39/Tsugane cells were transplantable intraperitoneally into nude mice, and produced abdominal tumors and hemorrhagic ascites. These results indicate that P39/Tsugane is the first cultured cell line of myelomonocytoid nature to be derived from overt leukemia following MDS. Therefore, P39/Tsugane cells should be useful for studies on the differentiation of leukemia cells, the pathogenesis of MDS and in vitro-in vivo experimental chemotherapy.
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PMID:A novel human myelomonocytoid cell line, P39/Tsugane, derived from overt leukemia following myelodysplastic syndrome. 659 19

Activation of monocytes and granulocytes in vitro by cytokines, in vivo administration of cytokines, as well as in vivo cytokine production due to infectious and inflammatory diseases causes changes of the surface expression density of certain membrane molecules. In recent studies we attempted to determine the feasibility of using flow cytometric immunophenotyping as a tool to develop a sensitive parameter for detecting infections at an early stage of disease when clinical parameters are still negative. Since infections are an important factor determining the clinical course of myelodysplastic syndromes (MDS), early detection of infection might be beneficial for these immunocompromised patients. We indeed found activation-associated immunophenotypic changes of cell surface antigens on monocytes and granulocytes of clinically infection free MDS patients suggesting enhanced immune activity in these patients, most likely due to latent or beginning infections. In particular, analyses of the expression density of receptors for IgG (Fc gamma Rs), complement receptors, and certain activation-associated surface molecules such as the CD67 and the M5 molecule seem to be of clinical relevance. We will also discuss findings concerning changes of cytokine levels and functional alterations of immunologic parameters in MDS patients.
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PMID:Immunological findings in patients with myelodysplastic syndrome. 786 69

The surface expression of effector cell molecules on neutrophils was examined in 18 patients with myelodysplastic syndromes (MDS) and 20 healthy control subjects. The MDS patients were further classified as low clinical risk (L-MDS, n=7) and high clinical risk (H-MDS, n=11). The expression of Fc receptors for IgG (FcR), complement receptors (CR) and cellular adhesion molecules on neutrophils was determined by flow cytometry and monoclonal antibodies. The effect of granulocyte colony-stimulating factor (G-CSF) and tumour necrosis factor-alpha (TNF) on L-selectin shedding and CR up-regulation on neutrophils was also examined. The percentage of FcRI-positive neutrophils and CD11b/CR3 expression on neutrophils were significantly increased in the H-MDS patients when compared to the controls. In contrast, the expression of FcRII, FcRIII, L-selectin, LFA-1 and CD18 on neutrophils was significantly reduced in the H-MDS patients compared with the controls. The L-MDS neutrophils exhibited lower expressions of CR1, L-selectin, LFA-1 and CD18 than those of the controls. Neutrophils from some H-MDS patients showed impaired L-selectin shedding and CR up-regulation after stimulation with G-CSF or TNF, although these were not significantly different when assessed in the whole H-MDS group. These findings suggest that an altered surface expression of effector cell molecules and an impaired modulation of cellular adhesion molecules on neutrophils may contribute to the increased susceptibility to bacterial infections in MDS patients.
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PMID:Altered surface expression of effector cell molecules on neutrophils in myelodysplastic syndromes. 923 72