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Biomedical subjects

D J Cameron

Publications and source records attributed to D J Cameron.

79 records · Page 5Linked to original sources
PubMed1976

The aetiology of diarrhoea in newborn infants.

Diarrhoea is a common problem in newborn infants in hospital nurseries. In the past, sporadic diarrhoea was often attributed to dietary indiscretion by the mother, and epidemic diarrhoea was though to be caused by an unknown infectious agent. Techniques with which to locate non-cultivable viruses and untypable enteropathogenic strains of Escherichia coli allow reevaluation of the aetiology of diarrhoea in newborn infants. Preliminary results from Melbourne, Australia, suggest that most diarrhoea in newborn infants is induced by a specific infectious agent. During 1975 the agent most often identified from sporadic and epidemic diarrhoea in hospital nurseries was a reovirus-like particle ("duovirus"). Enterotoxin-producing strains of E. coli were rarely isolated. Future attempts to protect newborn infants from developing diarrhoea must be based on an accurate understanding of the aetiology of this disease.

Australia↗
PubMed1976

An enzyme-linked procedure for the detection and estimation of surface receptors on cells.

An enzyme immunoassay procedure has been developed for the visualization and estimation of lymphocyte surface receptors. beta-Galactosidase (beta-gal'ase) was covalently linked to sheep anti-rabbit immunoglobulin (SARIg), to ovalbumin (OA), and to adenosine (A). Exposure of rabbit peripheral lymphocytes to SARIg-beta-gal'ase and subsequent incubation with the fluorogenic substrate fluorescein-beta-digalactopyranoside allowed visualization of B cells by fluorescence microscopy. Treatment with each of the above beta-gal'ase conjugates and incubation with another fluorogenic substrate, 4-methyl-beta-D-umbelliferylgalactopyranoside, made possible the estimation of the various receptors by spectro fluorimetry. Procedures used for enrichment of T and B cell populations could be monitored. Among the findings was that immunoglobulin-bearing cells (presumably B cells) formed rosettes with sheep erythrocytes. The quantitative procedure was used to study lymphocyte population changes during immunization with an A-O A conjugate. An increase in the binding of A-beta-gal'ase, SARIg-beta-gal'ase, and OA-beta-gal'ase by peripheral lymphocytes occurred repeatedly 6 to 8 days after immunization but lasted only a few days despite a continued high circulating antibody titer. These results are consistent with the possibility that immunization induces migration of lymphocytes into the circulation from bone marrow and/or thymus.

Adenosine↗
PubMedDate not supplied

Upper and lower gastrointestinal endoscopy in children and adolescents with Crohn's disease: a prospective study.

Fifty-six children and adolescents with Crohn's disease were prospectively investigated with gastroscopy and colonoscopy irrespective of localizing symptoms or signs. Routine biopsies were taken from endoscopically normal and abnormal areas. A high incidence (71%) of upper gastrointestinal (GI) involvement was found. In 41%, these findings were instrumental in making the diagnosis. The ileum was viewed in 49 of the 56 cases. Overall, the upper GI tract was involved in 71%, the terminal ileum in 53%, and the colon in 86% (oesophagus 16%, body of stomach 46%, antrum 36%, duodenum 21%, terminal ileum 53%, caecum 69%, transverse colon 71%, sigmoid 60% and rectum 41%). Upper and lower gastrointestinal endoscopy with systematic biopsies should be performed early in the diagnostic assessment of children and adolescents with suspected inflammatory bowel disease to enable accurate diagnosis and assessment of extent of disease.

Adolescent↗
PubMedDate not supplied

Helicobacter pylori infection in children.

Helicobacter pylori was sought prospectively by culture of antral biopsy, histology and serology (IgG and IgA) in 440 consecutive endoscopies on children to determine the prevalence, clinical presentation and histological features of H. pylori infection in our population. Twenty-eight patients had H. pylori (8% overall). The mean age of infected patients was significantly higher than that of non-infected patients (P less than 0.0001). No patient under 5 years of age had H. pylori isolated. Overall, there was no significant difference in clinical presentation between those with and those without H. pylori infection, but 23% of patients 5 and 26 years of age who presented with abdominal pain as the indication for their endoscopy had H. pylori isolated. Macroscopic changes ranged from no abnormality to frank ulceration, but the typical antral mamilliform changes were 100% predictive of infection. Fifty-eight per cent of patients with duodenal ulcers, but only 17% with gastric ulcers had H. pylori infection. Histological gastritis was present in 144 patients (including all H. pylori positive patients). None of the patients with another definable cause for gastritis had H. pylori isolated. In conclusion, H. pylori is an important cause of primary gastritis in our population, occurring in children over 5 years of age. Culture of an antral biopsy should be performed in children over this age undergoing endoscopy for the investigation of abdominal pain and, more particularly, in those with peptic ulceration.

Adolescent↗