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Biomedical subjects

R J Miles

Publications and source records attributed to R J Miles.

69 records · Page 4Linked to original sources
PubMed1983

Study of the interaction of Saccharomyces cerevisiae with glucose by particle microelectrophoresis.

Saccharomyces cerevisiae NCYC 239 in the presence of glucose at temperatures under 303 K shows a time-dependent lowering of electrophoreric mobility v. At temperatures above 303 K, this time-dependent change in v is in the direction of increased mobilities. Cells suspended in buffer indicate a surface pKa of less than 4, whereas for cells suspended in buffered glucose it is impossible to derive a surface pKa. A kinetic study of the interaction of S. cerevisiae with glucose as a function of temperature allows calculation of an activation energy of 140 kJ X mol-1 for the combined processes of (i) uptake of glucose onto the cell wall, (ii) transfer through the cell wall and membrane, and (iii) the establishment of a steady glucose flux through the wall and membrane.

Biological Transport, Active↗
PubMed1983

Effect of some cultural factors on T1 broth vaccine for contagious bovine pleuropneumonia.

The effect of some aspects of buffering capacity, glucose concentration, length of incubation and extent of exposure to air during the preparation of live Mycoplasma mycoides var. mycoides strain T1 broth culture vaccine was investigated. A consistently good vaccine was obtained using 0.07 M phosphate buffered medium containing 0.1% glucose and incubating in stoppered bottles. The shelf-life of this vaccine stored at 4 degrees C was up to 12 weeks. The effect of other storage temperatures on the viability of the vaccine is given.

Animals↗
PubMed1980

Antibiotic bioassay by flow microcalorimetry.

A rapid, sensitive microcalorimetric bioassay of good reproducibility has been developed for the antibiotics penicillin-G, carbenicillin, ampicillin and cefoxitin. The use of growing organisms as responding agents allows discussion of the results for systems which may involve biological fluids.

Anti-Bacterial Agents↗
PubMed1980

Bioassay of phenol disinfectants by flow microcalorimetry.

A rapid flow microcalorimetric method for the bioassay of phenol disinfectants is described. The assay may be used for phenol within the range 50-80 mM with a reproducibility of +/- 2%. Assay results on other phenols examined indicate the range of the assay. Commercial disinfectants may be assayed directly (the flow microcalorimetric technique makes no demands for optical clarity nor absence of suspended material on the solutions used) with the same reproducibility. An in-use concentration of the chosen disinfectant may be selected from the experimental data since the flow microcalorimetric output permits "time-to-death' of the test organism to be observed directly.

Calorimetry↗
PubMed1979

Antibiotic sensitivity testing by flow microcalorimetry.

The proposed flow microcalorimetric method for the diagnosis of bacteriuria has been extended to include antibiotic sensitivity testing. Sensitive organisms rapidly (4-8 min) show thermal responses to the added antibiotics over the normal range of concentrations (1 x, 2x, MIC value).

Anti-Bacterial Agents↗
PubMed1979

The application of cryobiology to the microbiological assay of nystatin.

Improvements in the reproducibility of nystatin agar diffusion assays have been achieved by the use of liquid nitrogen stored inocula and deep frozen standard stock solutions. The overall percentage variability of the assay has been reduced from over 5% with daily prepared standards and inocula to around 1% with a frozen inocula and to 0.6% with a combination of frozen inocula and standards. The implications of these improvements in the standardization of nystatin assays, and microbiological assays generally are discussed.

Biological Assay↗
PubMed1979

A comparative study of the microbiological assays currently available for nystatin raw material.

The classical agar diffusion and turbidimetric methods of assay for nystatin are compared with the more recently documented assays for this antibiotic which depend upon physicochemical measurement of the response of micro-organisms. Liquid nitrogen stored inocula were used throughout. It is concluded that the newer methods of assay are as reproducible and reliable as the agar diffusion and turbidimetric methods and that they are generally more sensitive. The choice between the assay methods compared can thus be based on speed, cost and sample through-put.

Biological Assay↗
PubMed1978

In vitro studies of amphotericin B in combination with the imidazole antifungal compounds clotrimazole and miconazole.

The clinically important polyene antibiotic amphotericin B, in combination with two antifungal imidazole compounds, clotrimazole and miconazole, was studied in vitro. With use of results of cytoplasmic leakage, metabolic heat output, and minimal inhibitory concentration studies, a definite antagonistic response was demonstrated. It is suggested that, if combined antifungal drug therapy is clinically indicated, the drug combination be tested against the isolate by the simple technique of measuring cytoplasmic leakage or by the more elaborate method of flow microcalorimetry.

Adsorption↗
PubMed1970

Scale design of metric rules and slide rules.

The design of metric draughtsmen's scale rules is discussed as if they were indicating instruments with straight scales. A minimum distance between marks of 1 mm is recommended and some suggestions for experimental designs are made. Slide rules are also considered with a view to improving their legibility.

Journal Article↗
PubMedDate not supplied

Successful use of a feeding obturator for an infant with a cleft palate.

The report of case presents the postnatal and early infancy period for a child born with a cleft of the soft palate. The infant was admitted to the hospital several times for failure to thrive as a result of feeding difficulties. The feeding problems resulted from both the cleft and a lack of consistent and concerted effort by the family to nourish the infant. When the child was 3 months old, a feeding obturator was constructed that resulted in improvement in the child's weight gain. The feeding problems of an infant with a cleft palate and the pressures that these problems present to the parents are discussed.

Cleft Palate↗