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Biomedical subjects

S C Bailey

Publications and source records attributed to S C Bailey.

25 records · Page 2Linked to original sources
PubMed1988

Enhancement of gamma-glutamyl transpeptidase expression in bone marrow cells by colony stimulating factors.

Studies on blood serum from mammary carcinoma (MC) hosts, which promoted gamma-glutamyl transpeptidase (GGT) expression by normal rat bone marrow cells in liquid culture, were extended to various granulocyte-macrophage colony stimulating factors (CSFs). GGT concentration per cell was found to increase (without change in total cell number) by incubation for 48 h with purified CSF-2 gamma and CSF-1 (but not interleukin-3), with human giant cell elaborated GM-CSF and L-cell conditioned medium, as well as with the 3 MC preparations (host serum, MC extract and MC conditioned medium). GGT-inducing ability (per milligram protein) ranked the 7 preparations in the same order as did their proliferative effect (number of colonies per milligram protein) in the standard mouse bone marrow agar culture system. The quantitative correlation between these two kinds of activities (linear for their logarithmic values) was highly significant, r = 0.976, p less than 0.001. The alkaline phosphatase concentration of bone marrow cells in liquid culture was also increased in the presence of the same 7 preparations, and this again was proportional (r = 0.985, p less than 0.001) to their colony stimulating potential.

Animals↗
PubMed1987

Characterization of a mammary carcinoma elaborated factor stimulating gamma-glutamyltranspeptidase expression in bone marrow cells.

The elevation of bone marrow gamma-glutamyltranspeptidase (GGT) and alkaline phosphatase (AP) content in rats carrying mammary carcinoma 5A (MC), reproduced in a short-term (48-h) liquid culture of normal bone marrow cells, was found to be attributable to a blood-borne protein factor with an apparent molecular weight of 60,000. Partial purification, based on the extent of stimulation of GGT expression in this culture, increased the specific activity of the host serum from 1.5 to 40 units and that of MC extracts from 6 to 560 units. Production of the factor by MC in vitro, however, resulted in specific activities of 3000 units in the conditioned medium, and a further 60-fold purification was achieved by DEAE-cellulose, Sephadex G-100, and hydroxylapatite chromatography. The chemical characteristics of the MC-elaborated protein indicate nonidentity to previously isolated colony formation stimulating factors which also induced GGT (and AP) expression by rat bone marrow cells. Most of the AP inducing ability of the MC-serum and MC-conditioned medium copurified with and was still present in preparations with the highest specific activity vis à vis GGT. In mouse (instead of rat) bone marrow cells, however, no AP response accompanied the stimulation of GGT expression by MC (or colony formation stimulating factor) preparations.

Alkaline Phosphatase↗
PubMed1979

Repetitive DNA in Escherichia coli: multiple sequences complementary to small stable RNAs.

Radioactively labeled 4.5S, 6S, and 10S RNAs from Escherichia coli were hybridized to EcoRI fragments from the E. coli genome. Each of these molecules bound to more than one DNA fragment. Cot curve analysis of the kinetics of the annealing of these RNAs to denatured E. coli DNA suggests that the DNA corresponding to each of these molecules is reiterated in the genome. These experiments also suggest that these reiterated sequences are non adjacent.

DNA, Bacterial↗
PubMed1978

Small stable RNAs from Escherichia coli: evidence for the existence of new molecules and for a new ribonucleoprotein particle containing 6S RNA.

Small stable RNA molecules of Escherichia coli other than 5S (rRNA) and 4S (tRNA) were studied. Two of the molecules corresponded to 4.5S and 6S RNA, which have been reported previously. The third stable RNA molecule, 10S RNA, has not been described before. RNA labeled with (32)P(i) or [(14)C]uracil for a relatively long time, when separated in 5%/12% tandem polyacrylamide gels, displayed three bands corresponding to 10S, 6S, and 4.5S RNA in addition to rRNA and tRNA bands. These RNAs were stable in pulse-chase-labeling experiments. The amount of these RNAs was small, comprising only 0.2 to 0.5% of the total (32)P incorporation. However, this amount represented a large number of molecules; for 6S and 4.5S, it was about 1,000/DNA molecule. These three RNAs were found in the postribosomal supernatant fraction. None of them was found in purified nucleoid fractions in which the tightly coiled DNA molecules were contained. Of these three RNAs, 6S RNA was unique in that it seemed to exist in a ribonucleoprotein particle. All these RNAs, as well as tRNA, were very stable in the cell under various physiological conditions. 5S RNA was less stable. On the other hand, purified 6S RNA was more susceptible than tRNA to cell nucleases when incubated with cell extracts, suggesting that, being in a particle, it is protected from cell nucleases.

Electrophoresis, Polyacrylamide Gel↗
PubMed1977

Identification of lipopolysaccharides and phospholipids of Escherichia coli in polyacrylamide gels.

Polyacrylamide gel electrophoresis of unfractionated lysates of radioactively labeled cells resolves not only proteins and polynucleotides into discrete bands but also cellular lipopolysaccharides and phospholipids. This allows a determination of the intracellular amounts of all of these macromolecules. In addition, this technique is sensitive enough to detect mutational alterations in lipopolysaccharide structure. Polyacrylamide gel electrophoresis is herein shown to be a useful tool for investigations into the structure of lipopolysaccharides and the synthesis of lipopolysaccharides and phospholipids.

Electrophoresis, Polyacrylamide Gel↗