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Biomedical subjects

W G Taylor

Publications and source records attributed to W G Taylor.

At least 73 records · Page 4Linked to original sources
PubMed1978

Population density as a factor in the evolution of neoplastic cell lines.

The influence of population density in the progression from the nonneoplastic to the neoplastic state has been reassessed. Two twice-cloned, nonneoplastic mouse lines, NCTC 7914 and 7915, were transferred each 3 to 4 days at inoculum sizes selected to minimize or maximize cell-cell contact, 1 X 10(5) or 4 X 10(5) cells/T-15, respectively. As tested by in vivo assay, the regime designed to minimize cell-cell contact did not reproducibly delay transformation, and tumor production was observed in all lines, irrespective of inoculum size. Also, results of tumorigenesis assays correlated with blind evaluation of morphological and cytological alterations, growth in agarose, and susceptibility to killing by activated macrophages. Generally higher saturation densities were seen as a function of period in culture, and no significant differences in glucose utilization or lactic acid production were observed between nonneoplastic and neoplastic cell populations.

BCG Vaccine↗
PubMed1977

Mitomycin antibiotics. Synthesis and activity of 1,2-disubstituted mitosenes.

cis-1-Acetamido-2-acetoxy-7-methoxy-N-methylmitosene was prepared in 11 steps from 7-methoxy-6-methyl-2,3-dihydro-1H-pyrrolo[1,2-a]indol-1-one by a route involving bromination of the pyrrolidineenamine or trimethylsilyl enol ether of starting material, displacement of bromide by acetate, oxime formation, and reductive acetylation, followed by elaboration of the quinone and methyl carbamate functions according to previously established methods. An unsubstituted carbamate could not be prepared. The mitosene thus synthesized differs from previously reported 1,2-disubstituted mitosenes, which are derived from the solvolysis of mitomycins, in that it has the opposite arrangement of oxygen and nitrogen substituents at the 1 and 2 positions. It showed antibacterial activities in disk-plate assays superior to those of cis-diacetylapomitomycin A and equivalent to those of certain 1-substituted mitosenes; however, it was less active than mitomycin A in these assays. It was inactive in inducing lambda-bacteriophage in Escherichia coli and inactive against P388 leukemia in mice. In contrast, certain 1-substituted mitosenes were active in prophage induction and 2b and mitomycin A were active in both assays.

Animals↗
PubMed1975

Evaluation of nuclear-substituted styryl ketones and related compounds for antitumor and cytotoxic properties.

A number of nuclear-substituted styryl ketones, the related Mannich bases, and allyl alcohols were synthesized and evaluated for antitumor activity, principally in the L-1210 lymphoid leukemia and P-388 lymphocytic leukemia screening tests. The cytotoxicity of some of these compounds assessed in Eagle's 9KB carcinoma cell culture system was also recorded. Two of the Mannich bases showed promising levels of activity in the P-388 screening; of the results obtained to date, over one-third of the derivatives showed cytotoxicity at dose levels of 1-3 ppm. Other pharmacological results of these compounds are briefly reported.

Animals↗
PubMed1975

Structure and stereochemistry of some 1,2-disubstituted mitosenes from solvolysis of mitomycin C and mitomycin A.

Starting with mitomycin C (1), a number of solvolytic reactions were investigated and were found to result in opening of the aziridine ring with loss or migration of the 9a-methoxy group. A careful examination of the resulting 1,2-disubstituted 7-aminomitosenes indicated that there was a strong tendency for the azridine ring on opening to furnish mainly one stereoisomer, always with the oxygen stom at C-1 and the nitrogen atom at C-2. Thus the hydrolysis of 1withdition to small amounts of the trans-aminohydrin (10). Mitomycin A (2) BEHAVED ANALOGOUSLY. Both 1 and 2 generated a cis-1-acetoxy-2-acetamide when they were allowed to react with acetic anhydride. Acetolysis of mitomycin C was found to give the cis-1-hydroxy-2-acetamide (5), the trans-1-acetoxy-2-amine (14), and a cis-trans mixture of 1-acetoxy-2-acetamides (4 and 11, respectively). Routes to cis-1-methoxy-2-acetamide (9) were possible through the methanolysis of 1 or through the methylation of 5. For comparison, the trans-1-methoxy-2-acetamide (16) was obtained through a dnown resin-catalyzed methoxy migration from C-9A TO C-1 IN MITOMYCIN C. The use of 1-H nmr spectroscopy to asign configurations to 1,2-disubstituted mitosenes is discussed.

Hydrolysis↗
PubMedDate not supplied

Studies on isometheptene metabolism. Identification and stereochemistry of a major metabolite isolated from rat urine.

By gas chromatography-mass spectrometry of both underivatized samples and N-acetates, the major urinary metabolite of the antispasmodic drug (+/-)-isometheptene in the rat was identified as trans-2-methyl-6-methylamino-2-hepten-1-ol. The structure and stereochemistry of the metabolites was confirmed by comparing the properties of its N-acetate with those of an authentic sample of the N-acetate of trans-2-methyl-6-methylamino-2-hepten-1-ol which was obtained by a stereospecific trans-allylic hydroxylation of isometheptene acetate with selenium dioxide in ethanol. cis-2-Methyl-6-methylamino-2-hepten-1-ol was identified as a minor urinary metabolite of isometheptene in the rat.

Alkenes↗