Biomedical subjects

R P Watson

Publications and source records attributed to R P Watson.

5 recordsLinked to original sources

PubMed2001

Histopathology of experimental plague in cats.

Formalin-fixed paraffin-embedded archival tissues of seven adult cats of both sexes that died after being experimentally infected with Yersinia pestis were examined light microscopically to characterize the lesions. The cats were exposed in two groups using two routes of infection: ingestion of Y. pestis-infected rodent or a subcutaneous injection of Y. pestis to simulate a flea bite. Immunohistochemistry was performed on tissues from all organ systems from a representative cat from each group to determine the distribution of Y. pestis bacilli during infection. In all seven cats, bubonic plague lesions were seen. The lesions of pneumonic plague were present in two cats. Septicemic plague was confirmed in all seven cats by bacteriologic culture. Aggregations of bacteria were seen in lymphoid tissue in all cats and in lung tissues from the two cats with pneumonic plague. The most consistent histologic finding was necrosuppurative inflammation in the lymph nodes. Invariably, Y. pestis bacteria were present in large numbers at affected sites. Orally infected cats had more numerous lesions in the lymph nodes of the head and neck regions. These experimentally induced cases of feline plague document that cats are unique among carnivores in exhibiting bubonic, pneumonic, and septicemic plague following exposure to Y. pestis. The lesions of the orally infected cats were consistent with those previously described for naturally occurring Y. pestis infections in cats and corroborate the contention that cats most commonly contract plague by eating Y. pestis-infected rodents and not via flea bite. The histopathology of Y. pestis disease in these cats is comparable to that described for human plague.

Animals↗

PubMed2001

Intestinal permeability tests in coeliac disease.

Intestinal permeability tests have been used to screen for a wide range of small intestinal diseases, including coeliac disease and enteric infections. Several probe molecules have been used to investigate intestinal permeability including monosaccharides, disaccharides, 51Cr-EDTA and polyethyleneglycol. While many factors may affect intestinal permeability tests, the use of two probe molecules, for example, lactulose and mannitol, and the expression of the result as a ratio minimises the effects of these extraneous factors. Rendering the test solution hyperosmolar was also found to increase the sensitivity of the test in detecting coeliac disease. Intestinal permeability is characteristically elevated in untreated coeliac disease, with a sensitivity of up to 96% for the dual sugar techniques. The reason for this is a consistent increase in the absorption of lactulose (via the paracellular route) due to increased "leakiness" of the intestine and a reduction in the absorption of mannitol (via the transcellular route) due to a reduction in surface area as a result of villous atrophy. The intestinal permeability test allows subjects to be selected for jejunal biopsy in whom the clinical features are compatible with coeliac disease and in timing a follow-up biopsy. It has been postulated that raised intestinal permeability may be involved in the pathogenesis of coeliac disease. Recently, serum measurements of the probe molecules may have a valuable role, particularly in paediatric patients. Sucrose permeability has also been proposed as an accurate marker of adult coeliac disease and shows promise as a noninvasive test.

Celiac Disease↗

PubMed2000

Characterisation, chromosomal localisation and expression of the mouse Kid3 gene.

Kid1 encodes a transcriptional repressor implicated in the differentiation of renal epithelial cells. Here we report the characterisation of Kid3, a novel mouse gene related to Kid1. Kid3 encodes a C2H2 zinc finger protein with an N-terminal KRAB transcriptional repression domain. It maps to chromosome 11, adjacent to Kid1 and another related gene Kid2. Northern analysis shows that Kid3 is highly expressed in embryonic and adult brain, with lower levels in adult and embryonic (E16.5) kidney, gut, lung and heart. Expression of Kid3 in the kidney is developmentally regulated and suggests a role for Kid3 in the early stages of nephrogenesis.

Amino Acid Sequence↗

PubMed1996

Factors associated with serum antibodies to reticulin, endomysium, and gliadin in an adult population.

BACKGROUND: Gluten sensitivity is thought to be significantly under-diagnosed in the population. AIMS: The aims of this study were to investigate the prevalence of antibodies associated with coeliac disease in a large representative sample of the adult population and to determine factors that are associated with their presence. PATIENTS: Serum samples from 5420 subjects with approximately equal numbers in each five year group from ages 15 to 65 years were obtained from the Belfast MONICA project and Change of Heart surveys, set up to monitor and assess risk factors associated with coronary heart disease in the population. METHODS: Using immunofluorescence and enzyme linked immunosorbent assay (ELISA) techniques autoantibodies, including those to reticulin, endomysium, and gliadin were determined. RESULTS: The results establish that IgA antigliadin antibody prevalence is high at 5.7%. Antiendomysial antibody was present in 1.2% of samples and gliadin and endomysial antibodies in 0.4%. No significant differences were found between men and women, area of residence in Northern Ireland or the year of sampling over the eight year period. However, there was a significant increase in the prevalence of IgA gliadin antibody, and to a lesser extent IgA endomysial antibody, with increasing age. CONCLUSION: The high prevalence of these positive antibodies suggests that coeliac disease may be relatively common in Northern Ireland.

Adolescent↗

PubMed1991

Intergroup violence and intergroup attributions.

Pettigrew's (1979) prediction that relative to in-group behaviour, negative out-group behaviour would be attributed to internal characteristics, was tested in the context of Northern Ireland's continued conflict. Catholic and Protestant respondents were presented with newsreel footage depicting scenes of in- and out-group violence. One showed a Protestant attack on mourners at a Catholic funeral. The other showed a Catholic attack on a car containing two plain clothes soldiers at a Catholic funeral. Using a free response format, subjects' explanations were classified into internal and external attributions. The results showed strong support for Pettigrew's hypothesis. The implications of these findings with regard to the maintenance of intergroup conflict are discussed.

Adult↗