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Biomedical subjects

K E Wilson

Publications and source records attributed to K E Wilson.

46 records · Page 3Linked to original sources

Difficidin and oxydifficidin: novel broad spectrum antibacterial antibiotics produced by Bacillus subtilis. II. Isolation and physico-chemical characterization.

The isolation of difficidin (1) and oxydifficidin (2) from fermentation broth of Bacillus subtilis ATCC 39320 and the physico-chemical characterization of these labile antibiotics are described. The structures of the compounds represent a new class of antibiotics, characterized as highly unsaturated 22-membered macrolide phosphates. Difficidin and oxydifficidin undergo reversible thermal isomerization to 3 and 4 respectively. Biological evaluation of the isomers is presented.

Alkaline Phosphatase↗

N2-(1-carboxyethyl)methionine. A 'pseudo-opine' in octopine-type crown-gall tumours.

A novel methionine-containing plasmid-determined compound, N2-(1-carboxyethyl)methionine (NCEM) has been identified in crown-gall tumours induced by octopine-type strains of Agrobacterium tumefaciens. NCEM is probably synthesized by octopine synthase. Cell-free preparations from octopine-type strains of A. tumefaciens can degrade NCEM; however, the bacterium cannot transport the compound into the cell, although these strains can take up and degrade the octopine family of opines.

Arginine↗

Biosynthesis of the beta-lactam antibiotic, thienamycin, by Streptomyces cattleya.

Radioactive- and stable isotope-containing substrates were used to identify the biosynthetic precursors of the beta-lactam antibiotic, thienamycin, in Streptomyces cattleya. Acetate is utilized by the organism to form C(6) and C(7) of the beta-lactam ring. The two carbons of the hydroxyethyl group attached to C(6) are both derived from the methyl of methionine. The cysteaminyl side chain attached to C(2) is derived from cysteine. Selective inhibition of thienamycin and cephamycin C biosynthesis has been achieved either through the addition of metabolic inhibitors or through manipulation of the growth medium. These results suggest that the two beta-lactam antibiotics, thienamycin and cephamycin C, are formed by different biosynthetic pathways.

Magnetic Resonance Spectroscopy↗

Northienamycin and 8-epi-thienamycin, new carbapenems from Streptomyces cattleya.

Two new carbapenem antibiotics, northienamycin and 8-epi-thienamycin have been isolated from culture broth of Streptomyces cattleya grown under conditions for thienamycin production. The isolation, structure elucidation and in vitro antibacterial spectra of the new carbapenems are reported. In addition, comparison of the in vitro potency of the corresponding formamidine derivatives to that of MK787 is presented.

Anti-Bacterial Agents↗

Amenability to counseling of opiate addicts on probation or parole.

Fifty-two opiate addicts were classified as abstainers or continued abusers by their probation or parole officer. Eighteen variables--nine demographic and nine psychological--were evaluated for all subjects. Following factor analysis, 13 remaining variables were entered into a stepwise discriminant function analysis which significantly differentiated the abstaining and abusing groups. Abstainers were characterized by less dogmatism, higher education and personality integration, fewer aggressive incidents and previous drug arrests, and older age. The discriminant function classified 78.8% of the observations correctly and accounted for 27% of the variance. Rokeach's Dogmatism Scale, the Personality Integration Subscale of the Tennessee Self-Concept Scale, and the effective demographic discriminators have been included in a screening battery for counseling amenability by which incoming opiate addicts scoring like abstainers are granted priority in treatment assignment.

Age Factors↗

Avermectins, new family of potent anthelmintic agents: isolation and chromatographic properties.

The avermectins, a family of new anthelmintic agents, were isolated from the mycelia of Streptomyces avermitilis. Four closely related major components and four homologous minor components were separated from the complex. Solvent extraction, solvent partition, and adsorption methods were used to isolate and purify the complex; novel partition chromatography systems using Sephadex LH-20 were used to separate the components. A reverse-phase high-pressure liquid chromatography assay for the quantitative determination of all components was used extensively to monitor the purification methods.

Anthelmintics↗