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Biomedical subjects

H Pang

Publications and source records attributed to H Pang.

107 records · Page 6Linked to original sources
PubMed1982

Lysine tRNAs from Bacillus subtilis 168: structural analysis.

The primary sequence was established for two lysine tRNA isoacceptors which differ in abundance during development in Bacillus subtilis. Both tRNAs shared the same primary sequence but differed in the degree of post-transcriptional modification in the anticodon loop. The earlier eluting species, tRNA lys 1, had an unmodified C in position 32 and a mixture of N-[9-beta-ribofuranosyl) purin-6-ylcarbamoyl]-L-threonine, t6A, and N-[(9-beta-D-ribofuranosyl-2-methylthio-purin-6-yl)carbamoyl]threonine, ms2t6A, in position 37. The later eluting species, tRNA Lys 3, which is the more efficient in protein synthesis, had a modified C in position 32 and only ms2t6A in position 37. The possibility exists that modification to make a more efficient tRNA species may be part of a functional interaction between the translational and transcriptional changes that are part of the differentiation process in B. subtilis.

Anticodon↗
PubMed1982

Structure of a modified nucleoside in archaebacterial tRNA which replaces ribosylthymine. 1-Methylpseudouridine.

The structure of a modified nucleoside isolated from Halococcus morrhuae tRNA has been established as 1-methylpseudouridine, based on mass spectrometry and gas chromatography carried out on 0.2 A260 unit of material. Not previously found in nucleic acids, 1-methylpseudouridine appears to be unique to archaebacterial tRNA, where it replaces ribosylthymine in the T psi C loop of most of the tRNAs examined thus far.

Chromatography, Gas↗
PubMed1982

Identification of nucleosides in hydrolysates of transfer RNA by high-resolution mass spectrometry.

High-resolution mass spectrometry has been investigated as a technique for identification of modified nucleosides in unfractionated hydrolysates of transfer RNA. The method is based on recognition of predetermined sets of exact mass values which are characteristic of individual nucleoside components. Mass spectra are photographically recorded in a non-time-resolved fashion, so that differing rates of nucleoside vaporization are of no consequence. Experimental parameters of sensitivity, spectrometer resolution and rates of vaporization were studied. Under typical conditions, 1-4 micrograms of tRNA are hydrolyzed, converted to volatile trimethylsilyl derivatives, and mass spectra of the resulting mixture recorded during 3 min at resolution 20 000; 75-100% of the minor nucleosides are usually identified in a single recording. The method is complementary to conventional methods of identification which rely on chromatographic mobilities, and can in principle be generally applied to recognition of biologically or chemically modified bases in nucleic acid.

Chemical Phenomena↗
PubMedDate not supplied

Gender identity disorder and HIV disease.

Four cases of male-to-female transsexuals with HIV infection are described, showing that individuals with gender identity disorder are vulnerable to HIV infection through unsafe sexual behaviour and intravenous drug use. The various practical problems associated with carrying out major surgery on this group of individuals are discussed, as well as some of the ethical issues raised by their treatment needs.

Adult↗