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Biomedical subjects

G M Davies

Publications and source records attributed to G M Davies.

13 recordsLinked to original sources

Synthesis and structure-activity relationships of cephalosporins with C-3' catechol-containing residues.

Cephalosporins with new catechol substituents at C-3' have been synthesized, including novel compounds with C-3' carbon-carbon bonds. Many of these compounds have high potency against Gram-negative bacteria, in particular against resistant strains like Pseudomonas aeruginosa. Structure-activity relationships are discussed in terms of their dependence on the pKa of the C-3' catechol and also in terms of steric and conformational factors of the C-3' substituent. The best overall properties were found in compounds with a bulky and/or conformationally restricted acidic C-3' catechol.

Animals

Children's knowledge of court proceedings.

This paper describes a study of children's legal vocabulary and their knowledge of criminal court procedures. Subjects (aged six, eight, 10 years and adults) were also asked about their feelings regarding a hypothetical court appearance as a witness. All subjects, children and adults, performed best on a vocabulary recognition section, with descriptions and concepts proving more difficult. Observed developmental trends in both legal vocabulary and conceptual appreciation of criminal law replicates previous work from Australia and America and supports the contention that children younger than 10 years are not well informed about the legal system. Results indicated clear deficits in knowledge as well as frequent misconceptions regarding legal personnel and procedures.

Adult

Six-month double-blind, controlled trial of high dose, concentrated beclomethasone dipropionate in the treatment of severe chronic asthma.

A six-month double-blind controlled trial compared a 2,000 microgram per day dose of beclomethasone dipropionate aerosol (BDP), with current upper level doses of 800 micrograms per day of the standard BDP, in asthmatics requiring oral corticosteroids in addition to BDP and bronchodilators. Both groups showed a significant reduction in their oral steroid requirements during the study, with a 34 percent reduction in the lower dose group and a 57 percent reduction in the high dose BDP group while maintaining good symptomatic control of asthma; there was an associated improvement in baseline serum cortisol levels. Over the same period, the pulmonary function of the lower dose group showed significant worsening relative to that of the group receiving the high dose BDP which improved. There was no increase in dysphonia or oropharyngeal candidiasis among those using the concentrated BDP. We conclude that high dose concentrated BDP appears to be a safe medication in long-term steroid-dependent asthma, and is effective in reducing dependence on the use of oral corticosteroid with associated improvement both in pulmonary and adrenal function.

Administration, Inhalation

Safety and efficacy of long-term treatment with inhaled beclomethasone dipropionate in steroid-dependent asthma.

An open long-term trial of inhaled beclomethasone dipropionate was carried out in 32 asthmatic patients chronically dependent on systemic corticosteroids. Our objectives were to study the efficacy and safety of beclomethasone and to determine the proportion of patients in whom systemic steroids could be replaced by the new drug. All subjects had a clear history and physical findings of asthma as well as significant improvement in respiratory function after inhalation of salbutamol. Patients were followed for 4 to 8 years. Compared with a baseline period, patients receiving beclomethasone had reduced symptoms and needed less bronchodilator therapy, but their pulmonary function was unchanged. Bronchial biopsy specimens from seven patients who had been taking beclomethasone for as long as 8 years did not differ histologically from specimens from five asthmatic patients who had never taken the drug. Nine patients were able to stop taking systemic corticosteroids within 9 months, eight required them occasionally, and in eight the requirement was substantially reduced; the requirement did not change appreciably in the remaining seven. Inhaled beclomethasone is a safe and effective drug for chronic administration to asthmatic patients, and in 78% of our subjects the need for systemic steroids was substantially reduced or eliminated.

Administration, Inhalation

Yellow nail syndrome.

The case of a patient with yellow nail syndrome (YNS), an infiltrating duct carcinoma of the breast, and giant cell interstitial pneumonitis (GIP) is presented. YNS has not been previously described in association with GIP. There was improvement of the yellow fingernails following surgery and chemotherapy for the breast cancer. The possible pathogenesis of the yellow nails in this case and its management are presented. A wide variety of conditions are associated with YNS, which has been reported to respond to various treatment modalities. The most likely cause in our case is impaired lymphatic drainage. However, treatments that do not affect lymphatic drainage also have been reported to be successful.

Breast Neoplasms

Identification of familiar and unfamiliar faces from internal and external features: some implications for theories of face recognition.

Three experiments are reported in which recognition of faces from whole faces or internal or external features was compared. In the first experiment, where the faces were of famous people, an advantage was found for identification from internal features. In the second experiment involving unfamiliar faces, however, no difference was found in recognition rates when subjects were given the internal or the external features. In a third experiment famous faces were presented and mixed with other famous faces for a recognition test. As in experiment 1, better recognition occurred from internals as compared with external features. It is argued that the internal representation for familiar faces may be qualitatively different from that for face seen just once. In particular some advantage in feature saliency may accrue to the internal or 'expressive' features of familiar faces. The implications of these results are considered in relation to general theories of face perception and recognition.

Discrimination Learning

Similarity effects in face recognition.

Three experiments are described which examine the effects of similarity on face recognition using a new application of hierarchical clustering analysis (HCS). Experiments I and II employed a within-groups design where subjects attempted to recognize targets among decoys from the same and different cluster to the target. Common cluster membership accounted for 72% and 84%, respectively, of all false alarms in the two experiments. Absolute error rates were affected by the number of targets actually present in the array and the style of the instructions given to subjects but were not influenced by whether successive or simultaneous test presentation was employed. Experiment III used a between-subject design where targets were embedded in arrays composed from same or different clusters. False alarm rates were significantly higher for the same cluster condition, but hit rates were unaffected by recognition context. The significance of these findings for theories of face identification is discussed.

Adolescent

A mortality study of coke oven workers in two South Wales integrated steelworks.

Six hundred and ten coke oven personnel were studied retrospectively over a period of 11 years (1954-65). During this time 82 died, 88 retired and 80 left, but all were treated. The Standardised Mortality Ratios (SMRs) have been calculated for four principal causes which have then been further analysed into 30 subgroups. The work was limited because the population was small and the records not detailed enough to analyse the mortality rates according to environmental exposures. Differences between SMRs obtained at the two works were quite marked (73 and 98) and the overall SMR of 85% was better than expected. The observed number of deaths from respiratory disease, malignant neoplasms and all other causes excluding cardiovascular, was very near that expected, but the numbers of deaths from cardiovascular disease and in particular arteriosclerotic disease, showed a significant deficit.

Adolescent