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Biomedical subjects

S R Heard

Publications and source records attributed to S R Heard.

26 records · Page 2Linked to original sources
PubMed1987

Association between production of toxins A and B and types of Clostridium difficile.

One hundred and seventy two strains of Clostridium difficile isolated from 62 patients with antibiotic associated diarrhoea or pseudomembranous colitis were analysed for the production of toxins A and B and typed using 35S-methionine labelling followed by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). There was a correlation between production of toxins A and B and the type of C difficile. One hundred and forty four of 172 strains were either high or low producers of both toxins. Toxins were not detected in 28 of 172 strains. Types A and Y were consistently non-toxin producers; types B and E were high toxin producers. Type X, the epidemic strain, showed variable toxin production. Symptoms of 49 patients with haematological malignant pathology who were part of a documented outbreak of antibiotic associated diarrhoea, were analysed in relation to toxin production and type of the clinical strains isolated. In general, there was a correlation between symptoms of antibiotic associated diarrhoea, the type of C difficile, and its potential for producing toxins.

Anti-Bacterial Agents↗
PubMed1987

Teaching medical ethics symposium. A student-led approach to teaching.

It is increasingly agreed that ethics has a place in undergraduate medical education. There is, however, debate about how it should be taught, and by whom. We present our experience of teaching ethics in a general practice module over six years. During this period there has been a shift from a teacher-centred to a student-centred approach in which students choose ethical issues to explore within a framework provided. The issues raised are discussed with examples, and the future directions of our ethics teaching outlined.

Bioethical Issues↗
PubMed1986

Immunoblotting to demonstrate antigenic and immunogenic differences among nine standard strains of Clostridium difficile.

The epidemiology of Clostridium difficile-associated disease is being elucidated with the development of typing schemes for the organism. We recently described a new typing scheme based on the incorporation of [35S]methionine into bacterial proteins followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography. Nine standard strains were identified. We report here some observations on the antigenic differences among these nine strains when studied by immunoblotting. Type-specific rabbit antiserum was raised against each of the nine standard strains. Immunoblotting of the strains with these antisera demonstrated, in addition to the presence of shared, common proteins, a type-specific response with homologous antisera. When [35S]methionine-labeled C. difficile proteins were immunoblotted with homologous and heterologous antisera, both the immunoblots and the autoradiographs demonstrated the same strain-specific response. These strain-specific proteins, which have been so useful for epidemiological and typing purposes, were also immunogenic.

Animals↗
PubMed1985

Gastrointestinal colonization and septicaemia with Pseudomonas aeruginosa due to contaminated thymol mouthwash in immunocompromised patients.

An outbreak of septicaemia with Pseudomonas aeruginosa amongst adult men with haematological malignancy involved eight patients on the same ward during a period of 5 weeks. The strains isolated from blood cultures from seven patients were indistinguishable by conventional typing methods. Thymol mouthwash which had been made up and distributed in communal jugs was found to be contaminated with the epidemic strain and was the likely source for this outbreak. A high rate of gastrointestinal colonization with the epidemic strain was found in the patients receiving the contaminated mouthwash. Only those patients with prolonged severe leucopenia developed septicaemia. Communal medications are an unnecessary hazard, particularly in oncology wards.

Adolescent↗