The formation of cyanide by a Chromobacte?ium violaceum strain was studied with growing cultures and with nonproliferating cells grown in complex and chemically defined media. Most of the cyanide was produced during the log-phase growth of the organism, and accumulated in the culture supernatant fluid. A synergistic effect of glycine and methionine on cyanide formation in a chemically defined medium was observed, and the amount of cyanide formed was found to be dependent on the concentrations of the two substances. Cyanide formation by nonproliferating cells was stimulated by preincubation with glycine and methionine. Cyanide formation by adapted cells in the presence of glycine and methionine was stimulated by succinate, malate, or fumarate, and depressed by azide and 2,4-dinitrophenol. Methionine could be replaced by betaine, dimethylglycine, and choline.
The effects of transcendental meditation (TM) on plasma renin activity (PRA) and plasma concentrations of aldosterone, cortisol, and lactate were studied by measuring these variables before, during, and after 20--30 min of meditation. Subjects, who rested quietly rather than meditating, served as controls. There were no differences in the basal values for these variables between meditators and controls, but controls, in contrast to meditators, showed a significant increase in cortisol between the first (A) and second (B) samples of the control period. PRA increased slightly (14%) but significantly (p less than 0.03) during TM, but not during quiet rest in controls. Cortisol decreased progressively (after sample B) throughout the experiment to the same degree in both groups. Aldosterone and lactate did not change. The data do not support the hypothesis that TM induces a unique state characterized by decreased sympathetic activity or release from stress, but do suggest that meditators may be less responsive to an acute stress.
There is currently considerable interest in the physiological function(s) of polyamines. Investigations have shown many in vitro interactions of polyamines with various cellular components, particularly deoxyribonucleic acid (DNA), ribonucleic acid (RNA), and ribosomes; the in vivo role(s) of polyamines is still unclear (H. Tabor and C. W. Tabor, Pharmacol. Rev. 16:245, 1964). This is owing largely to the uncertainty concerning the in vivo distribution of polyamines within the cell. Extrapolation of in vitro binding studies of the polyamines to subcellular components to in vivo localization of the polyamines is complicated by the redistribution of these highly basic substances after cell disintegration. Recently, Adler et al. (Proc. Natl. Acad. Sci. U.S. 57:321, 1967) reported the isolation of a strain of Escherichia coli (K-12 P678-54) which produces miniature DNA-deficient cells designated "minicells." This unique property of this strain of E. coli provides a system to test whether there exists a pronounced preferential binding of the polyamines, or of a particular polyamine, to the DNA. If such were the case, one might expect the minicells to contain relatively less polyamines. We therefore examined the amounts of DNA, RNA, and polyamines of E. coli K-12 P678-54 and its minicells and have found no evidence for preferential binding of the polyamines to DNA. Growth of the organism (kindly provided to us by Dr. Adler) and the separation of the minicells from normal cells were carried out as described by Adler et al.
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