Biomedical subjects
A Urabe
Publications and source records attributed to A Urabe.
Modulation of normal myelopoiesis in vitro by retinoic acid.
The effects of retinoic acid (RA) on the proliferation and differentiation of normal myeloid progenitor cells (CFU-C) were studied. In general, RA at 10(-10) to 10(-6) M enhanced primary myeloid colony formation in the presence of colony-stimulating factor(s). However, macrophage colony formation was strongly inhibited by RA. This may be related to the finding that RA is able to differentiate bipotential HL-60 cells into granulocytes but not into macrophages. Moreover, secondary colony formation was always suppressed by the addition of RA to the primary cultures. It means that self-renewal capacity of CFU-C was suppressed by RA. This finding suggests that normal myelopoiesis will be suppressed eventually by RA.
In vitro assay of erythropoietin: simple determination in a small amount of human serum samples.
An in vitro method for the determination of erythropoietin (EPO) titres in human serum samples was developed to detect low levels of EPO titres in various haematological states. Fetal mouse liver cells (FMLC) were incubated in methylcellulose-containing media, and radioiron incorporation into haem was estimated in cultured FMLC. We could determine the concentrations of EPO from around 20 to 600 mU per ml of a very small amount of serum samples from patients and normal adults. Using this method, EPO titres of normal adults (54 +/- 31 mU/ml), chronic renal failure patients (29 +/- 23 mU/ml), aplastic anaemia patients (545 +/- 74 mU/ml), and polycythaemia vera patients (16 +/- 7 mU/ml) were determined.
[A case of bronchogenic adenocarcinoma successfully treated with human leukocyte interferon].
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Translation of erythropoietin-mRNA extracted from a human hepatocellular carcinoma.
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[Immunosuppression or androgen therapy for aplastic anemia: a cooperative study].
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[Bolus methylprednisolone therapy for aplastic anemia: a case report].
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[Analysis of peripheral lymphocyte subsets in patients with diffuse panbronchiolitis].
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[Effects of domperidone suppository against adverse reactions in digestive organs induced by cancer chemotherapy].
We examined the effects of domperidone suppository against adverse reactions in digestive organs to antitumor agents. Suppositories containing 60 mg of domperidone were given to 15 patients who were suffering from vomiting and nausea occurring with the use of antitumor agents, and the changes in each digestive symptom were evaluated overall. As a result, 13 patients out of 15 (86.7%) showed improvement of symptoms. There were no adverse reactions to domperidone suppositories.
Serum erythropoietin titres in the anaemia of premature infants.
Erythropoietin (EPO) titres in the serum of premature infants were determined by an in vitro method using radioiron incorporation into haem in fetal mouse liver cells in culture. The serum EPO titres in 12 premature infants at birth were significantly lower than those of normal adults. In those premature infants who developed anaemia the serum EPO titres increased significantly by 4-6 weeks after birth, confirming that EPO production increases in premature infants in early days of life.
Smouldering leukemia: cytochemical changes of leukemic cells associated with karyotypic evolution in transition to overt leukemia.
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Enhancement of human T lymphocyte colony formation by 12-O-tetradecanoylphorbol-13-acetate (TPA).
The effects of 12-O-tetradecanoylphorbol-13-acetate (TPA) on human T lymphocyte lymphocyte colony formation in vitro were investigated. The number of T lymphocyte colonies was increased 4-5 times over that of controls by the addition of TPA (10(-7) - 10(-9) M) to phytohemagglutinin (PHA)-containing cultures. Few colonies were observed when stimulated with TPA in the absence of PHA. In the cultures containing a sufficient amount of exogenous T cell growth factor (TCGF), the enhancement of T lymphocyte colony formation by TPA was not observed. TPA enhanced TCGF production by peripheral lymphocytes stimulated with PHA. The optimal concentrations of TPA for T lymphocyte colony formation were similar to those for TCGF production. These findings suggest that TPA enhanced T lymphocyte colony formation by stimulating endogenous TCGF production. Interestingly, T lymphocyte colony formation was not inhibited even at high concentrations of TPA that usually inhibit myeloid and erythroid colony formation. This difference may be due to different sensitivities to TPA between T lymphocyte colony-forming cells and myeloid and erythroid colony-forming cells.
Effects of 12-O-tetradecanoylphorbol-13-acetate on the proliferation and differentiation of normal and leukemic myeloid progenitor cells.
The effects of 12-O-tetradecanoylphorbol-13-acetate (TPA) on myeloid colony formation were investigated by initial and delayed addition of TPA to the cultures. In the human placental conditioned medium-stimulated cultures, TPA inhibited normal myeloid colony formation without any change in colony morphology when added at the beginning of culture. However, macrophage-like transformation of myeloid colonies by TPA was clearly observed after the delayed addition of TPA. Colonies and clusters already formed at the time of TPA addition wee exclusively neutrophilic. Two days after TPA addition, many colonies apparently contained macrophage-like cells. Within 4 days after TPA addition, almost all myeloid colonies transformed into the macrophage type. Parallel study of initial and delayed addition of TPA revealed that this macrophage-like transformation of neutrophilic colonies occurred at high concentrations of TPA that would fully inhibit colony formation if added initially. TPA caused similar effects on leukemic colony formation.
Erythroid progenitors in paroxysmal nocturnal haemoglobinuria.
In vitro colony formation of bone-marrow erythroid progenitor cells in patients with paroxysmal nocturnal haemoglobinuria (PNH) was examined. The numbers of early and late erythroid progenitors (BFU-E and CFU-E) showed wide variations; two cases out of eight cases of PNH showed decreased erythroid colony formation, but other cases showed normal or rather increased colony formation of BFU-E and CFU-E. The number of erythroid progenitors in patients with PNH may be related to the marrow cellularity.
A new method for permanent preparations of hemopoietic cells cultured in methylcellulose medium.
To obtain permanent preparations for morphologic examination of hemopoietic cells cultured in methylcellulose medium, a new method designated as "the membrane filtration technique" has been devised. Permanent preparations of erythroid colonies, bursts and leukemic colonies, which have been grown mainly in methylcellulose medium, are illustrated in this paper. The stages of differentiation of cells within these colonies can be easily recognized by means of Wright-Giemsa staining.
Induction of delta-aminolevulinic acid synthase and delta-aminolevulinic acid dehydratase in normal human bone marrow cultures.
Activities of delta-aminolevulinic acid (ALA) synthase and ALA dehydratase, the first and the second enzymes of the heme biosynthetic pathway, were determined in erythroid colonies derived from normal human bone marrow in culture. ALA synthase and ALA dehydratase were induced when normal human bone marrow cells were incubated in the presence of erythropoietin (Ep) in culture, and the extent of induction of ALA synthase as well as ALA dehydratase was dependent on Ep concentrations and culture periods. Both ALA synthase and ALA dehydratase were increased in cultured erythroid cells before the appearance of morphologically recognizable hemoglobinized colonies, corroborating the sequential induction of heme biosynthetic pathway enzymes in human bone marrow erythroid cells.
[A case of acute panmyelosis (author's transl)].
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[A case of polycythemia rubra vera, terminating in acute myelogenous leukemia (author's transl)].
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