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Biomedical subjects

B W Fry

Publications and source records attributed to B W Fry.

15 recordsLinked to original sources
PubMed1990

Perdeuteration of methoxyflurane reduces production of fluorometabolites in mice.

The fluorometabolites of perdeuterated methoxyflurane (D-MOF) compared to the nondeuterated form (H-MOF) were studied in mice. Inorganic fluoride (F) and an organic acid labile fluorometabolite (OALF) were determined at various post-administration times. At 100 minutes after D-MOF, F was decreased 32-38% and OALF was down to 33-45%. After 300 minutes F was 56% less and OALF was 46% less after D-MOF administration. OALF increased 35-38% when H-MOF and D-MOF were diluted in oil compared to the undiluted forms. At three times (10, 30, and 100 minutes) D-MOF resulted in reductions of F to 31-38% of values produced by H-MOF. Also, OALF was reduced to 38-46% with D-MOF compared to H-MOF. These studies suggest that the use of D-MOF in mice results in a significant decrease in the appearance of the fluorometabolites F and OALF. The accumulation of metabolites is thought to be responsible for nephrotoxicity of MOF; therefore, D-MOF should be a much safer agent for use in general anesthesia.

Animals↗
PubMed1985

The effect of cimetidine on the formation of methoxyflurane fluorometabolites in mice.

Pre-dosing of mice with cimetidine reduced the plasma levels of inorganic fluoride, one of the fluorometabolites of methoxyflurane. The reduction occurred as early as 10 and as late as 160 minutes after cimetidine injection, and it was seen at both 30 and 100 minutes after subsequent methoxyflurane administration. Multiple pre-dosings with cimetidine did not notably affect the fluoride response. These results may be of use in avoiding methoxyflurane toxicity, which is thought to be due to markedly elevated fluoride levels in some patients.

Animals↗
PubMed1984

Fluoride levels in dentin after iontophoresis of 2% NaF.

The fluoride in successive layers of dentin (from 3-6 micron were removed per etch) has been measured following topical or iontophoretic application of 2% aqueous sodium fluoride to coronal exposed dentin of freshly extracted human third molar teeth. The fluoride contents of the topical and iontophoresed first etches were, respectively, 12 and 22-31 times greater than that of control (untreated) teeth. Similarly, the fourth etches were 12 and 50-70 times greater, and the seventh (last sampled) etches were 5 and 28-41 times greater. There was no apparent change in acid solubility of the dentin as its fluoride content varied under the conditions of this study. This is the first report studying the fluoride content of extremely thin layers of dentin successively removed by acid etch and relating topical to iontophoretic uptake.

Acid Etching, Dental↗
PubMed1980

Early appearance of methoxyflurane fluorometabolites in mice.

The biotransformation of methoxyflurane produces two fluorometabolites: inorganic fluoride (F) and an acid-labile fluorocompound (OALF). These have been assayed in the serum of male mice 10, 30, and 100 minutes after either ip or sc injections of 0.7 microliter of methoxyflurane (MOF) per gram of body weight, as either the volatile liquid itself or as a 1:10 dilution in corn oil. During the 10- to 100-minute intervals, the mice were observed for loss of the righting reflex. Corn oil dilution significantly altered the production of MOF fluorometabolites, usually decreasing them, but after 100 minutes, the serum concentration of OALF was 25% greater. Loss of righting reflex was also altered; 11 of 18 mice given undiluted MOF experienced it, whereas only 2 of 18 given the diluted agent did. Compared to the tip route, the sc route resulted in less fluoride at all three time intervals, but more of the OALF after 30 and 100 minutes. None of the sc-dosed mice lost his righting reflex.

Animals↗