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Biomedical subjects

Y Takagi

Publications and source records attributed to Y Takagi.

At least 739 records · Page 41Linked to original sources
PubMed1978

Enhancement of the action of colony stimulating factor (CSF) by soluble component(s) of erythrocytes in mouse bone marrow cells cultures.

Rat erythrocytes, separated from other blood cells by SE-cellulose chromatography, were lysed by exposure to hypotonic solution, dialyzed and ultracentrifuged. The supernatant contained a substance which enhanced the activity of colony stimulating factor (CSF) in soft agar cultures of granulocyte-macrophage progenitor cells (CFU-C) from normal mouse bone marrow. The growth-enhancing effect of the erythrocyte factor was observed when mouse L-cell conditioned medium was used as the CSF source and also when serum from endotoxin-treated mice or from mice undergoing graft-versus-host reaction was used as the stimulant. The erythrocyte factor effect was also detected by 3H-thymidine uptake of bone marrow cells in liquid cultures. These results suggest that the effect of the erythrocyte factor on CSF is not restricted to CSF from a specific source nor to semi-solid agar cultures.

Animals↗
PubMed1978

Creatine kinase isoenzyme of high relative molecular mass in serum of a cancer patient.

We describe an atypical serum creatine kinase isoenzyme in the serum of a woman with cancer of the left breast. This isoenzyme migrated toward the cathode, closely following the MM isoenzyme on agarose gel electrophoresis. Its relative molecular mass was estimated to be about 325,000, fourfold that of normal creatine kinase. It is more heat-stable and is inhibited more by urea than the normal MM isoenzyme. Isoenzyme monomer B activity was observed to be 20 U/liter in the serum, as measured with use of an antibody against the M monomer. On anion-exchange column analysis, creatine kinase activity was observed only in the MM fraction, in spite of the fact that B activity was observed in the patient's serum. Results of the immunological investigation make it unlikely that the atypical isoenzyme is linked to immunoglobulin or beta-lipoprotein. It may have been present as the result of modification of normal creatine kinase by the therapeutic radiation the patient was receiving.

Breast Neoplasms↗
PubMed1977

Expression of a bacterial gene for guanine synthesis inserted into colicin E1 factor by an in vitro recombination.

Regulation of expression of a bacterial guaA gene inserted into colicin E1 DNA by an in vitro recombination was studied under various growth conditions. In Escherichia coli K-12 cells that carried this hybrid ColEl plasmid the level of guaA enzyme activity was not regulated by the concentration of guanine in the medium, but by the number of plasmid DNA copies. The optimal conditions for amplifying the guaA gene product by chloramphenicol treatment were determined. The level of guaA enzyme activity found under the optimal conditions was about 37 times that in extracts of wild-type E. coli cultured in guanine-free medium. The properties of the promoter for the guaA gene and applicability of this hybrid ColEl plasmid for amplification of various gene products were discussed.

Chloramphenicol↗
PubMed1977

Precocious induction of secretory granules by hormones in convoluted tubules of mouse submandibular glands.

Precocious differentiation of convoluted tubules of the submandibular glands of mice was induced by daily injection of thyroxine, insulin, hydrocortisone and 5alpha-dihydrotestosterone from day 4 after birth. This treatment induced enlargement of the tubules and synthesis of secretory granules in the tubules. Treatment with 5alpha-dihydrotestosterone alone had no effect on enlargement of the tubules or synthesis of the granules. These findings suggest that, besides androgenic hormones, these three hormones are also involved in synthesis of granules in developing mice.

Animals↗
PubMed1977

Purification and properties of human pancreatic deoxyribonuclease I.

Human pancreatic DNase I was purified extensively from duodenal juice of healthy subjects by a procedure including ammonium sulfate fractionation, ethanol fractionation, phosphocellulose fractionation, isoelectric focusing, and gel filtration. The final preparation was free of DNase II, pancreatic RNase, alkaline phosphatase, and protease. The enzyme had a molecular weight of approximately 30,000, as determined by gel filtration on Sephadex G-100, and showed maximum activity at pH 7.2-7.6. It required divalent cations for activity, and caused single-strand breaks by endonucleolytic attack on double- as well as single-stranded DNA molecules. The enzyme was inhibited by actin and bovine pancreatic DNase I antibody.

Deoxyribonucleases↗