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Biomedical subjects

J C Vickery

Publications and source records attributed to J C Vickery.

8 recordsLinked to original sources
PubMed1988

Multichannel digital recording of intraluminal temperature in the upper gastrointestinal tract of man: techniques and analyses.

A recording system has been developed to measure intraluminal temperature changes from six sites simultaneously in the upper gastrointestinal tract at rates up to 10 Hz from each site. The temperature probe contains six type K thermocouples mounted in 14 French gauge orogastric tube. The data is logged, after digital conversion and signal multiplexing, onto disc storage by a dedicated microcomputer. The fluctuating temperature profile, defined as temperature spikes, has been subjected to novel computer analysis to allow definition of temperature load and dissipation within the oesophagus, stomach and duodenum. This system enables the effects of drinking and eating hot and cold foods on the physiological functions of the gastrointestinal tract to be studied accurately.

Body Temperature↗
PubMed1980

Plasmid-mediated tissue invasiveness in Yersinia enterocolitica.

Plasmids have an important role in the pathogenicity of certain bacterial species, and Escherichia coli provides the most complete example of the relationship involved. Enterotoxigenic strains of E. coli, in addition to producing heat-stable and/or heat-labile enterotoxins, may also produce a haemolysin and fimbriate cell surface antigens which facilitate the adherence of the bacterial cell to the mucosa of the small bowel. Numerous studies have shown that these properties are plasmid-mediated and that the plasmids act in concert to confer on the host bacterium the ability to produce enteric disease in man and in animals. Moreover, studies with invasive strains of E. coli have shown that the Col V plasmid, which codes for the synthesis of colicin V, significantly enhances the pathogenicity of its host bacterium. Although the relationship between Col V plasmids and virulence is unclear, reports indicate that Col V-containing strains of E. coli are better able to survive in the alimentary tract and that colicine V itself inhibits macrophage function. It is probable that bacterial virulence is a complex phenomenon involving both chromosomal and plasmid genes. We describe here a virulence plasmid which mediates tissue invasiveness in human pathogenic strains of Yersinia enterocolitica.

Bacterial Toxins↗
PubMed1979

Implementing a computer-based electro-oculographic analysis system.

Electro-oculographic recordings of caloric-induced nystagmus were conducted in a number of normal and disordered subjects. On the basis of the results, implementation of a clinical measuring system is considered; this is based on the interbeat interval, selected in view of its favourable sensitivity and stability. Two stages of processing are involved; first, the determination of the interbeat intervals, second the analysis. The first stage has been implemented off-line on a general purpose computer and also, in on-line mode, by special purpose electronics. The second stage requires computer analysis. We have used the rank magnitude sequences of interbeat intervals as the basis of the analysis.

Adult↗