Biomedical subjects

Ingrid A F van der Mei

Publications and source records attributed to Ingrid A F van der Mei.

3 recordsLinked to original sources

PubMed2005

Multiple sclerosis: a haplotype association study.

Results are presented from a genomewide haplotype association study on multiple sclerosis (MS) cases from Tasmania, an island state of Australia. Cases were ascertained on strict clinical and radiological grounds and on the fact that they had at least one grandparent born in the state. This enriched for early settler chromosomes among present day Tasmanians with MS and increased the chances of finding common haplotype sharing at disease predisposition loci in distant relatives sharing common ancestral haplotypes. Four-to-five close relatives were also collected for each of 170 cases and 105 population-based controls. All were genotyped at a 5cM resolution, haplotypes reconstructed and sharing estimated using an empirical approach based on sorting haplotypes to find the most common at each locus and then generating a test statistic for excess sharing in the cases based on permutation testing. Five initial loci were found where there was an excess sharing in the cases. These were fine-mapped with 10-12 additional markers. Only loci on chromosomes 6 and 10 remained after fine mapping. These loci demonstrate an increase in sharing of multi-marker haplotypes in MS cases compared to both population control transmitted haplotypes and case non-transmitted haplotypes.

Haplotypes↗

PubMed2004

What affects your MS? Responses to an anonymous, Internet-based epidemiological survey.

Evolving information technology has raised the possibility of new methods of data collection in multiple sclerosis (MS) research. An anonymous, self-report, Internet-based survey was developed, which asked people with MS their opinion on how various extrinsic factors affected their condition. From September 2001 to July 2002, a total of 2529 people completed the questionnaire. The demographic and clinical profiles of the anonymous respondents indicated that most were likely to have MS. Common factors reported as beneficial were cannabis, cold baths, meditation and dietary factors. Common adverse factors reported were high stress, exposure to high temperatures and viral infections. There was an increasing report of high temperatures as being adverse with increasing respondent age (test for trend, P < 0.001). The adverse report of high temperatures correlated significantly with the report of strong sunlight apparently making MS worse (r = 0.35, P < 0.0001). In Australia, high temperatures were more likely to be reported as adverse in warmer, lower latitude regions. The association between strong sunlight as adverse and age or region did not persist after adjustment for high temperatures. Thus, this apparent adverse factor appeared to relate to solar heat, not solar light. People with MS may risk vitamin D deficiency because of sun avoidance due to heat-related fatigue or intolerance. This is of clinical significance not only for bone health but because vitamin D may have beneficial immunomodulatory properties. The present study provides new information from people with MS on factors that may influence symptoms or clinical course. This information will now be used in the design of formal epidemiological cohort studies.

Adolescent↗

PubMed2002

Misclassification due to body hair and seasonal variation on melanin density estimates for skin type using spectrophotometry.

Recent advances have enabled quite accurate estimations of cutaneous melanin density by spectrophotometry using reflectance of light at wavelengths 400 and 420 nm. Our purpose was to assess the effect of body hair and seasonal variation at the upper inner arm and buttock on measurements of melanin density. We estimated melanin density of 104 volunteers at 3-monthly intervals over 12 months both before and after shaving. Removing body hair at the upper inner arm had no effect, but substantially reduced melanin estimates at the buttock in men. Significant seasonal variation was only observed at the upper inner arm, with highest readings in summer-autumn. In case-control studies, misclassification due to body hair at the buttock and seasonal variation at the upper inner arm could affect the observed odds ratio substantially. However, both sources of error can be reduced by careful attention to key aspects of study design.

Adult↗