Inhibition of Thiamine Pyrophosphate Utilization by Thiamine or Its Monophosphate in Escherichia coli

The growth of a thiamine pyrophosphate auxotroph of Escherichi coli was inhibited by either thiamine or thiamine monophosphate, and the growth of a thiamine monophosphate auxotroph was inhibited by thiamine. The thiamine pyrophosphate-dependent oxidation of pyruvate was inhibited by thiamine with whole cells of the thiamine pyrophosphate auxotroph but not with cell extracts prepared from the same organism. In addition, the thiamine pyrophosphate uptake of the thiamine pyrophosphate auxotroph was inhibited by either thiamine or thiamine monophosphate. Although the thiamine pyrophosphate uptake of a revertant, selected for prototrophy from the thiamine monophosphate auxotroph, was inhibited by thiamine to an extent comparable to that observed with the thiamine monophosphate auxotroph, its growth was no longer inhibited by thiamine. A possible mechanism for the inhibition by thiamine and thiamine monophosphate in the utilization of thiamine pyrophosphate is discussed.     

Adenine-dependent growth of marine yeast,Rhodotorula glutinis var.salinaria under sodium chloride-hypertonic condition

Nitrate and ammonium were shown to alter the growth ofRhodotorula glutinis var.salinaria in saline and non-saline media. In saline medium in which ammonium was the sole nitrogen source, ammonium inhibited growth in the presence of molybdate ions. Detailed comparisons of the growth in saline and non-saline media when nitrate was supplemented in the presence of molybdate ions showed that differences in utilizability of purine bases of nucleic acid were responsible for the differences in growth,i.e. adenine increased the growth in such saline medium, but decreased it in non-saline medium. There was not such a specific requirement for adenine in saline medium in the presence of molybdate ions when nitrate was substituted for ammonium as the sole nitrogen source. It was suggested that adenine might provide the necessary skeleton of nucleic acid for serving nitrate reduction in saline medium.     

Occurrence of beta-chain conformation in poly-gamma-methyl glutamate membranes

Molecular chain conformations of poly-γ-methyl-L -glutamate, poly-γ-methyl-D -glutamate, and poly-γ-methyl-D ,L -glutamate in membranes prepared by using mainly trifluoroacetic acid and formic acid as solvents were investigated by infrared, X-ray diffraction, and optical rotatory dispersion measurements. It was pointed that these polymers exist in the α-helix form in membranes cast from trifluoroacetic acid solutions, but in the β-chain form in membrances swollen in formic acid. The β-chain structure was also observed in crystals precipitated from dilute solutions including formic acid. The formation of the β-chain structure was discussed.     

Electrocardiographic studies in the Japanese monkey (Macaca fuscata) with special reference to the effect of anesthesia with barbiturates

The electrocardiograms of 157 healthy Japanese monkeys (Macaca fuscata), covering a wide range of ages in both sexes, were recorded under light pentobarbital (Nembutal) anesthesia. Although results were generally similar to those reported for other macaque species, some quantitative differences were observed.The heart rate was about 160 per minute in all monkeys examined; the P-Q interval was 0.11±0.06 sec.; the duration of QRS was 0.04±0.01 sec.; the Q-T interval was 0.24±0.06 sec. The mean axis of QRS was +59° and the pattern of the QRS complex was qR type in most cases.The comparison with the human electrocardiogram shows that the heart rate ofM. fuscata is about twice that of man, while the P-Q, QRS, and Q-T intervals were about one-half of those found in human subjects. In the monkey, however, the P wave was sharp and the T wave flat.In order to estimate the effect of anesthesia on the electrocardiogram, the records of several monkeys before, during, and after intravenous administration of barbiturates were compared. Although some animals showed extrasystoles after barbiturate was administered, generally no essential changes were noted in the records, except for the retardation of the rate and proportional prolongation of intervals.This work was presented at the 10th Annual Meeting of the Primate Research Association held in Inuyama, March 13, 1966.     

Histochemical detection of l-gulonolactone: phenazine methosulfate oxidoreductase activity in several mammals with special reference to synthesis of vitamin C in primates

Summary An improved detection of activity of l-gulonolactone oxidase, which is responsible for the final oxidative step in the synthetic process of l-ascorbate from glucose in animals, was achieved using phenazine methosulfate and cyanide. Cold acetone fixation eliminated non-specific deposition of formazan on lipid droplets. The specificity of the method was tested and proven by a biological control, histochemical controls, inhibitors and activators. By application of the method, strong reactivity was found in the cytoplasm of centrilobular parenchymal cells of livers of the opossum, rat, ground squirrel and flying squirrel. Staining of dog liver was moderate and centrilobular. Prosimians were strongly positive: The centrilobular localization was found in the tree shrew and galago; slow lorises and some pottos showed strong reactivity in centrilobular cells and some peripheral cells as well. These prosimians seem to be able to synthesize l-ascorbate as many lower mammals are. On the contrary, true simians (i.e. the squirrel monkey, spider monkey, rhesus monkey and chimpanzee) were negative as guinea pigs were, suggesting their probable inability for l-ascorbate synthesis.Visiting scientist from the Department of Anatomy, Tokyo Medical and Dental University, Tokyo, Japan. T. R. Shanthaveerappa in previous publications, also fellow, Department of Anesthesiology, Emory University.     

Histochemical studies on urate oxidase in several mammals with special reference to uricolytic ability of primates

Summary Strong reactivity for urate oxidase was found in the liver parenchymal cells of the prosimians (i.e. the tree shrew, slow loris, potto and galago) as well as those of lower mammals. The liver parenchymal cells of the platyrrhine monkeys (i.e. the marmoset, owl monkey, squirrel monkey, capuchin monkey and spider monkey) were moderately positive. There was no preferential distribution of granular reaction products in zones of liver lobules of these species. The prosimians and platyrrhine monkeys seem to be uricolytic as lower mammals are. On the other hand, the old world monkeys (i.e. Java monkey and rhesus monkey) and the apes (i.e. the orang-utan and chimpanzee) were histochemically negative.