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Biomedical subjects

D F McCafferty

Publications and source records attributed to D F McCafferty.

30 records · Page 2Linked to original sources
PubMed1987

Reduced adherence of micro-organisms to human mucosal epithelial cells following treatment with Taurolin, a novel antimicrobial agent.

Taurolin, a non-antibiotic antimicrobial agent, significantly reduced the adherence of buccal and vaginal strains of Candida albicans blastospores and urine isolates of Escherichia coli and Staphylococcus saprophyticus to epithelial cells. Light microscopy and radio-isotopic counting methods were used to quantify the adherence of the micro-organisms to either uroepithelial or buccal epithelial cells. A maximum reduction in adherence of approximately 65% was obtained. The anti-adherence capacity was time-dependent, requiring a contact time of 30 min to achieve maximum effect. Taurolin at sub-minimum inhibitory concentrations (MIC) significantly reduced the adherence of Candida and E. coli. A concentration slightly higher than the MIC was required for Staph. saprophyticus. Treatment of either epithelial cells or micro-organisms with Taurolin resulted in reduced adherence of microorganisms.

Anti-Bacterial Agents↗
PubMed1987

A comparative study of the microbial antiadherence capacities of three antimicrobial agents.

The antimicrobioal agents, taurolidine, chlorhexidine and povidone-iodine were examined for microbial anti-adherence activity. Two adherence systems were investigated using light microscopic and radio-isotopic assay methods: that of an oral isolate of Candida albicans to human buccal epithelial cells and of a urine isolate of Escherichia coli to human uroepithelial cells. Each of the three agents exhibited significant anti-adherence activity which was concentration dependent. The activity was expressed at subminimum inhibitory concentrations of the agents. Treatment of either the microbial or epithelial cells resulted in significant reductions in adhering micro-organisms. Consideration of the data in respect of the skewness coefficient and percentage clear epithelial cells indicated that the agents exhibited a broadly based anti-adherence capacity.

Anti-Bacterial Agents↗
PubMed1986

Decrease in adherence of bacteria and yeasts to human mucosal epithelial cells by noxythiolin in vitro.

Adherence of buccal and vaginal isolates of Candida albicans to buccal epithelial cells and the adherence of urine isolates of Escherichia coli and Staphylococcus saprophyticus to uroepithelial cells was quantified by light microscopy. The antimicrobial agent noxythiolin reduced the adherence of these micro-organisms in both exponential and stationary growth phases. Adherence of both the blastospore and pseudohyphal forms of C. albicans was reduced. Treatment of epithelial cells and/or micro-organisms with noxythiolin resulted in decreased adherence. No anti-adherence effect was observed with formaldehyde and N-methylthiourea, the degradative products of noxythiolin.

Adhesiveness↗
PubMed1986

Inhibition of hyphal development and kill of Candida albicans blastospores by noxythiolin in vitro.

The cidal activity of the antimicrobial agent, noxythiolin, was investigated against a laboratory strain and a fresh isolate of Candida albicans. The order of resistance to noxythiolin was hyphal form (isolate) greater than or equal to 25 degrees C-grown blastospores (isolate) greater than 37 degrees C-grown blastospores (isolate) greater than laboratory strain blastospores. Noxythiolin activity was superior to that of 'equivalent' formaldehyde concentrations. Mycelial transformation in C. albicans was examined by light and scanning electron microscopy and measured in terms of percentage germination and hyphal extension. Noxythiolin, 2.5%, in contact for 30 min prevented germination of the blastospore population whereas the decomposition products, formaldehyde and N-methylthiourea, showed no appreciable effect in the expected concentrations. The implications of these results are discussed in relation to the observed clinical efficacy of noxythiolin.

Candida albicans↗
PubMed1985

The effect of ultrasound on the percutaneous absorption of lignocaine.

The influence of ultrasound on the percutaneous absorption of lignocaine from a cream base was investigated in a double-blind cross-over trial in healthy volunteers. Mean data indicated that there was a slightly faster onset time for local anaesthesia when ultrasound was administered when compared with control values (no ultrasound). However, the differences were not statistically significant. Further controlled clinical studies are required into the effect of ultrasound on percutaneous absorption since the technique (phonophoresis) has been alleged to enhance percutaneous penetration of a number of drugs.

Double-Blind Method↗
PubMed1985

Differential pulse polarographic determination of formaldehyde in stored noxythiolin solutions.

A differential pulse polarographic method has been developed for the determination of formaldehyde, by means of its kinetic current, in noxythiolin solutions. The assay conditions have been optimized so that the noxythiolin decomposition reaction was not affected. The method had the advantage of rapidity with an analysis time of about 10 min per sample. Thus formaldehyde was determined in noxythiolin solutions prepared and stored under typical clinical conditions. The low concentrations of formaldehyde present in all solutions were insufficient to account for the known cidal action of noxythiolin. There must therefore be some doubt that the mode of action of noxythiolin is simply due to formaldehyde produced as a result of the decomposition of noxythiolin in aqueous solution.

Drug Stability↗
PubMed1985

A comparison of the antimicrobial activities of noxythiolin and formaldehyde solutions.

The availability of a rapid and highly specific polarographic method of analysis for formaldehyde enabled investigation of the rate of formaldehyde release from noxythiolin solutions and actual concentrations of formaldehyde in solutions during clinical use and storage. The antimicrobial activity of noxythiolin solutions, equivalent pure formaldehyde solutions and N-methylthiourea individually or in combination was examined against standard bacteriological strains and clinical isolates. Several interesting observations were made. Clinical isolates were found to be relatively susceptible to noxythiolin in contrast to laboratory strains. The growth phase of the organism radically affects activity, early exponential phase cells being susceptible to 1.0% noxythiolin. Levels of formaldehyde detected in fresh noxythiolin solutions are extremely low and would not appear to be solely responsible for the antimicrobial activity observed.

Bacteroides fragilis↗
PubMed1984

Stability of noxythiolin solutions stored in plastic and glass containers.

The stability of two different concentrations (1% and 2.5% w/v) of noxythiolin (Noxyflex and Noxyflex S) stored at a variety of temperatures (4, 20 and 37 degrees C) in both plastic and glass bottles has been examined over a period of 40 days. During this period noxythiolin solutions held at 20 degrees and 37 degrees C attained equilibrium (K = 0.285 +/- 0.015 mol/l). Neither noxythiolin nor its degradation products (N-methylthiourea and formaldehyde) were absorbed by the plastic (polypropylene) containers used. Therefore, noxythiolin solutions can be stored in certain plastic (polypropylene) containers under the same conditions as recommended for glass bottles.

Absorption↗
PubMed1983

A comparative assessment of a new antacid formulation based on magaldrate.

A new antacid formulation (Dynese) based on magaldrate, a discrete chemical entity with marked antacid properties, has been compared in vitro with several commercially available antacid preparations. All preparations were tested for their ability to maintain gastric pH within acceptable limits and to effectively bind bile acids. Sodium concentrations were also determined. Dynese was shown to compare very favourably with existing preparations in that it had a prolonged even neutralization profile, efficient bile acid binding properties and a low sodium content.

Aluminum Hydroxide↗
PubMed1982

Effect on particle size on the compaction mechanism and tensile strength of tablets.

The effect of particle size variation on tablet tensile strength for spray-dried lactose, Sta-Rx 1500 and Avicel PH-101 was investigated. Decreasing the particle size of spray-dried lactose and Sta-Rx 1500 resulted in stronger compacts whereas the tablet tensile strength of Avicel PH-101 was unaffected by particle size variation. The Heckel relationship, at two different contact times, was used to examine the predominant compaction mechanism. This was independent of the size fractions studied for all three materials. Angle of repose and Hausner ratio measurements indicated a correlation between the internal forces of friction and cohesion of the sized powders and the tensile strength of compacts formed from them.

Hardness↗