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Biomedical subjects

M Akashi

Publications and source records attributed to M Akashi.

At least 127 records · Page 7Linked to original sources
PubMed1988

Simultaneous expression of lymphoid and myeloid phenotypes in acute leukemia arising from myelodysplastic syndrome.

A 57-year-old female developed myelodysplastic syndrome (MDS) that terminated as a biphenotypic leukemia after exposure to chemoradiotherapy. Double staining of blast cells, using monoclonal antibodies specific for myeloid and lymphoid lineage, demonstrated that one-third of the leukemic cells simultaneously expressed the E rosette-associated antigen (OKT11) and myeloid-associated antigen (MY7). This finding suggests the possibility that some cases of MDS are clonal disorders that arise in a pluripotent stem cell that can also differentiate to T cell lineage.

Acute Disease↗
PubMed1988

Neutral and sialosyl glycosphingolipid composition and metabolism of human T-lymphoblastic cell line MOLT-3 cells: distinctive changes as markers specific for their differentiation.

Changes in the composition and metabolism of glycosphingolipid (GSL), which is one of the cell surface constituents, during cell differentiation of human T-lymphoblastic leukemia cell line MOLT-3 cells were examined with special reference to their alterations in E rosette-forming capacity and expression of surface antigens specific for T-cell lineage. Three molecular species of neutral GSL and greater than or equal to 13 molecular species of acidic sialosyl-GSL (ganglioside) were detectable on high-performance thin-layer chromatography (HPTLC) in untreated MOLT-3 cells. The major components were ceramide monohexoside and gangliosides GM3 and GD1a. When the cells were induced by 12-O-tetradecanoyl phorbol 13-acetate (TPA) to differentiate into more mature T cells, the ganglioside composition changed distinctively, and the total ganglioside content increased considerably; mono-, di-, and tri-sialosyl gangliosides concomitantly showed significant increase, but no new molecular species of GSL specific for the differentiation were detected. The activity of one sialyltransferases, CMP-sialic acid:CDH sialyltransferase, which synthesizes ganglioside GM3 and the total sialic acid content of the cell surface, parallelled the extent of cell differentiation. Examination of another human T-lymphoblastic leukemia cell line, HPB-ALL, indicated that TPA could also induce the cells to differentiate along T-cell lineage and that changes in the ganglioside pattern during differentiation are similar to those of MOLT-3 cells. The results indicate that human T-lymphoid cell differentiation intimately involves elongation of neutral oligosaccharide-moieties and the addition of sialic acid residues to gangliosides, resulting in more mature T cells containing higher gangliosides. Both the sialyltransferase activity and the sialic acid content, as well as the ganglioside pattern, might be new biochemical markers specific for human T-lymphoblastic cell differentiation.

Antigens, Surface↗
PubMed1987

[The clinical effect of low-dose Ara-C in patients with refractory acute nonlymphocytic leukemia and myelodysplastic syndrome].

Twenty-one patients with refractory acute nonlymphocytic leukemia (ANLL) and myelodysplastic syndrome were treated with low-dose cytosine arabinoside (LDARC). LDARC was administered by subcutaneous injection every 12 hours at a dose of 10 mg/m2 (regimen A) or at a dose of 20 mg/m2 by continuous intravenous infusion (CIV) or continuous subcutaneous injection (CSC) (regimen B). Among 22 courses, two elderly patients with ANLL (M4 and M5) and one M4 patient with myelofibrosis obtained complete remission (CR) and three elderly patients with ANLL (one M1 and two M2) and one patient with ANLL developed from RAEB in transformation obtained partial remission (PR). The overall remission rate (CR + PR) was 31.8%. The CR durations were 2.5, 5 and 2 months, respectively. The plasma concentration of Ara-C determined in regimen B was 8.26 +/- 4.12 ng/ml. There was no difference in the plasma concentration of Ara-C between CIV and CSC. We consider that the major mode of action of LDARC lies in its cytotoxic effect, since all patients who obtained remission exhibited pancytopenia and bone marrow hypoplasia. However, in several patients, we observed transient monocytosis and granulocytosis which were considered to be suggestive evidence of differentiation of leukemia cells.

Acute Disease↗
PubMed1985

Affinity chromatography of nucleosides and nucleic acid base derivatives with nucleic acid bases or nitrobenzeneboronic acid substituted silicas.

Nucleic acid bases such as adenine and uracil, and nitrobenzeneboronic acid substituted silicas were prepared by the reaction of chloromethylbenzene substituted silica with adenine sodium salt and trimethylsilylated uracil, and nitration of benzeneboronic acid substituted silica, respectively. From the results of HPLC of nucleosides and N-ethyl derivatives of nucleic acid bases using modified silicas, hydrophobic base stacking interaction, selective hydrogen bonding interaction between purine and pyrimidine bases, and reversible cyclic boronate ester formation between diols of nucleosides with boronic acid were effective for the separation of nucleic acid related compounds. Moreover, association constants for hydrogen bonding formation of nucleic acid bases were estimated.

Boronic Acids↗