Biomedical subjects
Publications and source records attributed to M B Davies.
A new physical sign (the 'toe up' sign) is described in relation to an irreducible Lisfranc injury, the cause being the interposed lateral slip of the tibialis anterior tendon. Surgical exploration is advocated.
In order to be able to compare the results of research work carried out in different centres on Alzheimer's disease and dementia, it is necessary for there to be standardised assessment methods. The Medical Research Council organised a workshop in order to see whether workers in Britain in the field of dementia research could agree on such standardised assessment methods. The workshop agreed guidelines for the minimum data which should be collected, in clinical and pathological studies, on patients with presumed Alzheimer's disease and dementia. These recommendations are compared with other approaches based on research diagnostic criteria.
When the EEG is averaged time-locked to blinks, and the part of the potential that is proportional to the EOG is subtracted, a signal (the 'residuum') remains which resembles an event-related potential (ERP). The blink time-locked average (BTA) was investigated to determine whether the components of the residuum are due to a cerebral blink-related potential or to artifacts of the EOG which subtraction failed to remove. The BTA was obtained from 12 subjects using voluntary blinking in the light and in complete darkness. Differences between the potentials in light and dark indicate that a major component of the residuum is a visual evoked response elicited by the off-on light stimulus associated with blink eye closure. The results are discussed in relation to attempts to correct blink artifacts in ERP experiments and, by drawing parallels between the residuum and the lambda potential associated with saccades, similar inferences are made for the correction of eye movement artifacts.
beta-glucosidase, cellulase, alpha-mannosidase, beta-galactosidase, and N-acetyl-beta-glucosaminidase were tested for their ability to hydrolyse the carboxymethylcellulose contained in 'Rely' tampons (R-CMC). The end-products of the hydrolysis were determined by chromatography. Only beta-glucosidase and cellulase hydrolysed R-CMC and the major product detectable after enzymic degradation was glucose, as confirmed chromatographically and by the glucose oxidase test. The enzymic-degradation products of R-CMC were able to support the growth of a toxic-shock-syndrome strain of Staphylococcus aureus. This finding suggests that as it is degraded by enzymes in the vaginal cavity R-CMC may become an exogenous source of nutrients for pathogenic organisms.
Transport of radioactively labelled peptides has been used to characterize a common transport system for di- and tripeptides in Candida albicans. This permease is energy-dependent and has a requirement for L-amino acid residues, an alpha-linkage between residues and a free amino terminus. Transport was followed by the accumulation inside the cell of intact peptides and component amino acids. After transport of glycyl-[U-14C]phenylalanine the radioactive material was accumulated inside the cell and subsequently leaked into the medium under certain conditions.