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Biomedical subjects

M Amano

Publications and source records attributed to M Amano.

At least 235 records · Page 13Linked to original sources
PubMed1983

Regulation of protein synthesis by estradiol 17 beta, dexamethasone and insulin in primary cultured Xenopus hepatocytes.

Changes in the protein synthesis of Xenopus hepatocytes caused by insulin, estradiol-17 beta (estradiol) and dexamethasone were studied by using a primary culture in serum-free medium. All of these hormones stimulated the synthesis of secretory and intracellular proteins. Dexamethasone induced or stimulated the synthesis of many proteins (though limited in number), whereas estradiol induced or stimulated relatively few proteins, including the yolk precursor protein vitellogenin. The majority of these proteins differed in molecular weight and/or isoelectric point. When hepatocytes were treated with both steroids, most of the proteins were synthesized at the rates expected from the single treatment of the respective steroids. Thus, each steroid selectively stimulated the synthesis of its specific proteins. However, exceptional proteins were observed, whose syntheses were stimulated only by double treatment. In contrast, insulin seemed to cause an overall increase in individual secretory protein synthesis.

Animals↗
PubMed1983

Chronic phencyclidine increases methionine-enkephalin level in mouse striatum.

The chronic administration of phencyclidine-HCl (PCP-HCl), 10 mg/kg, for 6-7 days resulted in a significant increase in the striatal methionine-enkephalin level, although acute administration induced no change of methionine-enkephalin level in this area. The methionine-enkephalin levels in other areas investigated, i.e. the medulla oblongata/pons, the midbrain, the hypothalamus and the cortex, were unchanged after chronic PCP treatment. These results suggest that chronic administration of PCP alters the enkephalinergic neuronal activity in the striatum.

Animals↗
PubMed1983

A Burkitt-type 8;14 translocation in a case of plasma cell leukemia.

In a 50-year-old patient with plasma cell leukemia, the leukemic cells were found to have a 14q+ marker chromosome derived from the same translocation as that seen in Burkitt's lymphoma, namely, t(8;14)(q24;q32). A 14q+ marker has been reported so far in 13 cases of plasma cell dyscrasia, but only in 3 of them was the origin of the extra material on the 14q+ identified by banding analysis. The present case is the first one shown to involve a 14q+ marker derived from a Burkitt-type 8;14 translocation. Of particular interest is the association of the 8;14 translocation with lymphoid malignancies of the B-cell lineage.

Chromosomes, Human, 13-15↗
PubMed1983

Two cases of acute promyelocytic leukemia with variant translocations: the importance of chromosome No. 17 abnormality.

Two patients with acute promyelocytic leukemia (APL) were found to have chromosomal translocations in their leukemic cells; one had a 46,XX,t(7;17)(q36;q22) and another a 46,XY,t(1;17)(p36;q21) karyotype. These two cases of APL seem to be the first involving variant translocations instead of the standard t(15q+; 17q-) translocation. The present cases strongly suggest that the rearrangement of chromosome #17, which occurs in bands of the q21-22 region of the long arm, is crucially important in the pathogenesis of APL.

Adult↗
PubMed1983

Enrichment of the poly (A) sequence and lack of enhancement of total RNA synthesis in cultured Xenopus hepatocytes by estradiol-17 beta.

The effect of estradiol-17 beta on RNA synthesis and the amounts of total RNA and polyadenylic acid were determined in primary cultures of Xenopus laevis liver parenchymal cells. Results showed that estradiol did not alter the RNA content significantly; control cells contained 11.9 +/- 0.34 micrograms and estradiol-treated cells 12.4 +/- 0.17 micrograms per 10(6) cells on day 2 of estradiol treatment, and 22.0 +/- 0.61 micrograms and 24.0 +/- 1.09 micrograms on day 5. Hybridization with [3H]poly(U) revealed that estradiol increased the poly(A) content about 1.2-fold more than in the controls on day 2 and 1.6-fold on day 5 of estradiol treatment. The actual rate of RNA synthesis was estimated from analyses of the kinetics of [3H]adenosine incorporation into the ATP pool and into RNA. The initial rate of incorporation of ATP into RNA on day 5 of estradiol treatment was 29.38 pmol/min/10(6) cells and the rate of the controls of 29.35. Subsequent accumulation kinetics of [3H]adenosine into RNA showed no difference between estradiol and the control cells. Thus, estradiol did not alter the rate of total RNA synthesis and the total RNA content significantly, but it did increase the poly(A) content.

Adenosine↗
PubMed1983

Quantitative study of deoxycytidine incorporation in large and small lymphocytes of the mouse.

Using radioautographic smear preparations of thymocytes and mesenteric lymph node (MLN) cells labelled with three different tritiated pyrimidine deoxyribonucleosides, the incorporation of DNA precursors was studied separately on large lymphocytes and small lymphocytes. Radioautographic reaction due to generally tritiated deoxycytidine ( [G-3H]CdR) labelling in vivo in large lymphocytes was more intense than that in small lymphocytes. When mice were sacrificed 6 hr after the administration of tritiated thymidine ( [3H]TdR), small lymphocytes were labelled more heavily than large lymphocytes. However, labelling intensity with [3H]TdR in large lymphocytes was greatly enhanced by the administration of 5-fluoro-deoxyuridine, whereas in small lymphocytes labelling intensity was only fairly enhanced by the same treatment. When cells were incubated in vitro with 5-tritium labelled deoxycytidine [( 5-3H]CdR) for 10 min, there was no significant difference in labelling intensities between large and small lymphocytes. In the case of [G-3H]CdR incorporation, the labelling intensity in large lymphocytes was found to be significantly stronger than that in small lymphocytes. Large as well as small lymphocytes incorporated [3H]TdR very well in vitro. However, addition of 5 X 0 X 10(-5) M of non-radioactive CdR to the medium greatly decreased the incorporation of [3H]TdR by large lymphocytes, whereas the effect of non-radioactive CdR in small lymphocytes was not so marked as that in large lymphocytes. Furthermore, the [3H]TdR-labelling percentages were decreased at the same rate by the addition of non-radioactive CdR in both large and small lymphocytes. These results indicate that large lymphocytes and a proportion of small lymphocytes have a strong tendency to convert CdR to thymidine mono-phosphate, which is utilized for DNA synthesis, whereas this ability is relatively weak in the rest of small lymphocytes. Thus, it is probably that this metabolic ability changes during the transition of the large lymphocyte to the small lymphocyte.

Animals↗