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R Notenboom

Publications and source records attributed to R Notenboom.

4 recordsLinked to original sources
PubMed2000

Serological analysis of a cryptosporidiosis epidemic.

BACKGROUND: A cryptosporidiosis epidemic occurred among residents and visitors to Collingwood, Ontario, during March 1996. Fifty-five per cent of 36 confirmed cases were Collingwood visitors and 57% of Collingwood resident cases were under 10 years of age. The low level of reported diarrhoeal illness among adult Collingwood residents caused government officials and physicians to question whether an epidemic had occurred in Collingwood. METHODS: To better evaluate the extent of the epidemic, anonymous surplus sera from 89 adult Collingwood residents, collected for routine tests prior to, during and after the epidemic, and from 80 adult Toronto residents were tested using a Western blot assay for IgG antibody response to two Cryptosporidium antigen groups (15/17-kDa and 27-kDa). RESULTS: For sera collected from 1 January 1996 to 17 June 1996, a higher fraction of Collingwood residents had a detectable serological response (P < 0.002) and the mean intensity of serological responses was higher for Collingwood than Toronto residents (P < 0.001). The mean intensity of serological responses for Collingwood residents was higher in specimens drawn during the 8 weeks following the initial case reports compared to those drawn before or after this period (15/17-kDa, P < 0.02; 27-kDa, P < 0.10). CONCLUSIONS: These elevated serological responses indicate that Cryptosporidium infections among Collingwood residents likely occurred more commonly than illness reports suggested, consistent with a community-wide cryptosporidiosis epidemic. Similar studies should be considered in future suspected cryptosporidiosis epidemic investigations.

Adult↗
PubMed1994

Seroreactivity to bacterial antigens is not a unique phenomenon in patients with autoimmune thyroid diseases in Canada.

It has been suggested elsewhere that the enteric pathogen Yersinia enterocolitica (Y.e.) might be implicated etiologically in autoimmune thyroid disease (AITD). To reevaluate this hypothesis in the Canadian population, where the prevalence of anti-Y.e. antibodies in the general population is very low (< 1%), we have studied the occurrence of antibacterial reactivity (against Y.e. 0:3 and 0:9, Escherichia coli and Staphylococcus aureus) in the sera of patients with Hashimoto's thyroiditis (HT), Graves' disease (GD), nontoxic nodular goiter (NTG), and autoimmune rheumatic diseases (ARD) as well as normal controls (C). Using the tube agglutination method, no single positive sample was detected in these subjects. No differences in the mean levels of anti-Y.e. 0:3 or 0:9 by ELISA were observed between various groups of patients. Immunoreactivity in the course of medical therapy during 5-12 months did not show significant changes in any of 12 ARD and AITD patients. Some serological reactivity to the plasmid containing strain of Y.e. 0:3 was demonstrated in all subjects by the Western blotting technique. However, weaker signals and fewer bands were noticed in these sera compared to sera from patients with acute yersiniosis. Analysis of the pattern of reactivity did not show any difference in reactivity to any protein between the groups of subjects. The immunodominant antigen in Y.e. 0:3 to which IgG reacted in almost all subjects was the plasmid encoded 240-kDa protein. Our study favors the view that there is a merely coincidental incidence of seroreactivity to bacterial antigens, which appears to be irrespective of diagnosis.

Antibodies, Bacterial↗
PubMed1980

Basilea rabbit immunoglobulins: detection and characterization by specific alloantiserum.

Evidence is provided for the existence of the Fbbas (Basilea) gene product (allotype). Specific antisera were raised by immunization of rabbits that did not possess the Basilea genes. With the help of these antisera, the Basilea allotype was detected in sera from rabbits, homozygous and heterozygous with respect to Basilea gene. The Basilea gene is expressed on a very low proportion of immunoglobulin molecules. The isoelectric point of the Basilea light chains is distinct from that of the lambda-light chains (peaks at pH 4.7 and 5.5, respectively). Sera from a large proportion of Ab9-positive rabbits of the Basel Institute for Immunology that were heterozygous at the Ab locus reacted with the anti-Basilea serum, even though they could no possess the Basilea gene at the Ab locus. Sera from Ab9-positive rabbits from Toronto were Basilea-negative. It was suggested that Ab9 and Basilea allotypes are controlled at closely linked loci. Ab9 haplotype prevalent in the Basel animal colony, possesses both Ab9 and Basilea genes, whereas the corresponding Toronto haplotype has only the Ab9, but not Basilea gene. The formation of the Basilea genotype was attributed to a crossing over, during which the Ab9 and Basilea genes separated.

Animals↗