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Biomedical subjects

S F Liu

Publications and source records attributed to S F Liu.

At least 91 records · Page 5Linked to original sources
PubMed1986

[Morphology of fungi in the slides prepared from esophageal balloons].

1,762 cases were selected at random from 17,000 persons screened by esophageal balloon in 4 communes of Linxian County. The morphologic appearance of fungi was studied in 4 slides of each case selected. According to the shape of clumps formed by fungi and bacteria in the slides, morphologic 4 types were seen: cotton-like, camel hair-like, hair-like and tree-branch-like. In the preliminary microscopic analysis, the following species of fungi were noted: Candida, Leptothrix, Actinomyces, Alternaria, Fusarium and Penicillium. Some of the fungi in the slides may have been taken from the oral or pharyngeal cavity, which may be due to, at least in part, the poor oral hygiene in the population examined. A positive association was shown between the quantity of fungi in the slides and the esophageal epithelial dysplasia and carcinoma, but its biological significance should be studied further.

Actinomyces↗
PubMed1984

Reductive fragmentation of 2-nitroimidazoles: amines and aldehydes.

Glyoxal has been identified as a product in the fragmentation of reduced 2-nitroimidazole radiosensitizers. Quantitative analysis of glyoxal as its bis (2,4-dinitrophenylhydrazone) derivative shows that it is formed in good yield (9-23%) in a variety of 2-nitroimidazoles. In addition to glyoxal a second as-yet-unidentified carbonyl compound, and a series of amines are formed when reduced 2-nitromidazoles fragment in the presence of water. One of the amines derived from misonidazole is identified as 1-amino-3-methoxypropan-2-ol, the product of extensive ring cleavage. Radiation chemical reduction of the 2-nitromidazoles proceeds with the consumption of 3 electrons for each molecule reduced. This could imply that a radical disproportionation or dimerization step is involved in the reductive degradation of 2-nitroimidazoles.

Amines↗
PubMed1978

Identification of a nitrone as an in vitro metabolite of N-methylamphetamine.

The relatively labile nitrone, alpha-methyl-(N-methylene) benzeneethanamine N-oxide was isolated from incubates of (+/-)-N-methylamphetamine with fortified liver honogenates from rats and rabbit. Identification of the nitrone was confirmed directly by gas chromatography and gas chromatography mass spectrometry and, after its conversion to isoxazolidine adducts by the action of methyl and ethyl acrylate. An authentic sample of the nitrone was synthesized unequivocally form N-hydroxyamphetamine and formaldehyde. The isomeric nitrone, N-(alpha-methylbenzeneethylidene) methylamine N-oxide, was also synthesized and its gas chromatographic and gas chromatographic mass spectrometric characteristics determined to confirm that the metabolically formed nitrone was not N-(alpha-methylbenzeneethylidene) methylamine N-oxide. Two previously unreported metabolites of (+/-)-Nmethylamphetamine, N-hydroxyamphetamine and 1-hydroxy-1-phenyl-2-propanone, were isolated from rat in vitro experiments; the latter metabolite was not produced in vitro by rabbit liver homogenates.

Amphetamines↗