Synthesis of cytochrome c oxidase in the liver of Rana catesbeiana tadpole treated with griseofulvin

The effect of griseofulvin treatment on the synthesis of cytochrome c oxidase was studied with the liver of the tadpole, Rana catesbeiana. (1) In the liver of tadpole treated with griseofulvin, a ferrochelatase inhibitor, the synthesis of heme a, but not cytochrome c oxidase protein, is inhibited. (2) The apocytochrome c oxidase which is formed in the liver of tadpole treated with griseofulvin is converted to the active holoenzyme by exogenously added heme a.     

An epidemiological study of Serratia marcescens infections by bacteriocin typing

Bacteriocin sensitivity typing according to the method of Traub (Appl. Microbiol. 1971. 21: 837-840) was carried out on 226 clinical isolates of Serratia marcescens obtained from inpatients at Nagasaki University Hospital during the period from January 1976 to December 1978. The isolates were divided into 16 different bacteriocin types, mainly 26, 4, and 9. The distribution of the types suggests that Serratia marcescens infections may be caused by cross infection. Reproducibility of bacteriocin typing and the relationship between serotypes (O-antigen) and bacteriocin types are discussed in regard to the application of this method to the study of nosocomial infections.     

Sex difference in susceptibility to teratogenic effect of maternal biotin deficiency in mouse embryos

When pregnant mice were fed biotin-deficient diets, cleft palate occurred more frequently in male fetuses than in female fetuses. Possible underlying mechanisms are speculated on, and some methodological problems in the analysis of sex-related differences in multiparous animals are discussed.     

Existence of a polar digitalis-like factor in mammalian hypothalamus

We were able to partially purify a polar digitalis-like factor from rat and bovine hypothalami based on the capacity to inhibit [3H]ouabain binding to intact human erythrocytes. This factor was characterized in reference to the digitalis-like factor that we have isolated and reported on. Hypothalamic factor shared digitalis-like activities and physicochemical properties with the one derived from human urine and mammalian plasma. These findings strongly suggest that a polar digitalis-like factor identical to the circulatory factor does exist in mammalian hypothalamus.     

Cloning of rabbit uricase cDNA reveals a conserved carboxy-terminal tripeptide in three species

cDNA clones encoding uricase have been isolated from a rabbit liver cDNA library. The nucleotide sequences of the cDNAs have been determined and those of the rat uricase cDNA have been revised. In all three uricases, the carboxy-terminal tripeptides are Ser-Arg/Lys-Leu sequences, which have recently been suggested as an essential element of peroxisomal targetting signals for many but not all peroxisomal proteins.     

Chimeric heterosis in mandibular size in mice

Morphometrical observations were carried out on the mandibles of chimeras made from the embryos of C57BL/6 and BALB/c mice to compare with the two strains and their reciprocal F1 crosses. The results of the principal component analysis indicate that the first principal component (PC1) and the second principal component (PC2) extracted might be acceptable as size and shape factors, respectively. Variations of both PC1 and PC2 were generally larger in the chimeras than in the two component strains and their F1 crosses. The mean PC1 value of the chimeras was larger than that of the two component inbred strains, and it was similar to that of F1 crosses, or slightly larger. The overall size of the mandible represented by PC1 tended to be larger in the chimeras consisting of two component cells that were approximately equivalent than in those that shifted to either cell population. The above trend was observed in both sexes. These results indicate that chimeric heterosis due to the interaction between genetically different cells (C57BL/6 and BALB/c) has some relation to mandible size. The mean PC2 value, which was accepted as shape factor, was intermediate between the two inbred strains. The mandible size (PC1) and shape (PC2) were bilaterally symmetrical, except for the shape in the female chimeras and in (C57BL/6 x BALB/c)F1.