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T Ohgi

Publications and source records attributed to T Ohgi.

21 records · Page 2Linked to original sources

Isolation of Q nucleoside precursor present in tRNA of an E. coli mutant and its characterization as 7-(cyano)-7-deazaguanosine.

One of the E. coli mutants selected for deficiency of modified nucleoside Q was found to contain an analogue of Q and normal guanosine in place of Q. The analogue of Q, designated as preQo, was isolated on a large scale from purified tRNATyr containing preQo. The structure of preQo was determined to be 7-(cyano)-7-deazaguanosine by comparison of its ultraviolet absorption spectra, thin-layer chromatographic mobility and mass spectrum with those of synthetic material.

Escherichia coli↗

Structure determination of a nucleoside Q precursor isolated from E. coli tRNA: 7-(aminomethyl)-7-deazaguanosine.

A precursor of modified nucleoside Q isolated from E. coli methyl-deficient tRNA was determined to be 7-(aminomethyl)-7-deazaguanosine. The structure was deduced by means of its chromatographic and electrophoretic mobilities, and UV and mass spectra, in addition to comparison with the synthesized authentic compound. The same molecule is also found in tRNA of an E. coli mutant selected for deficient synthesis of modified nucleosides.

Chromatography, Thin Layer↗

Intranasal tumor of the ethmoid olfactory mucosa in sheep.

Intranasal tumors (papillary adenomas or adenocarcinomas) of the ethmoid olfactory mucosa of sheep were investigated by light and electron microscopy. The fine structure of the tumor cells was characterized by the presence of numerous secretory granules. Viral particles, which were morphologically similar to a visna-maedi virus, were detected in all tumor tissues and in 3 of 4 cultures examined. The particles (about 97 nm) had an eccentrically located electron-dense core and numerous spikes on their surfaces. The RNA-dependent DNA polymerase activities in the tumor cells or the cultured cell from the tumor were greater than those in the normal intranasal tissues or the cultured cells from the choroid plexus. Viral particles similar to herpesvirus were also detected in 1 culture.

Adenocarcinoma↗