PubMed Health⌕ Search

Biomedical subjects

Ray Jupp

Publications and source records attributed to Ray Jupp.

3 recordsLinked to original sources

Making sense of microarray data distributions.

MOTIVATION: Typical analysis of microarray data has focused on spot by spot comparisons within a single organism. Less analysis has been done on the comparison of the entire distribution of spot intensities between experiments and between organisms. RESULTS: Here we show that mRNA transcription data from a wide range of organisms and measured with a range of experimental platforms show close agreement with Benford's law (Benford, PROC: Am. Phil. Soc., 78, 551-572, 1938) and Zipf's law (Zipf, The Psycho-biology of Language: an Introduction to Dynamic Philology, 1936 and Human Behaviour and the Principle of Least Effort, 1949). The distribution of the bulk of microarray spot intensities is well approximated by a log-normal with the tail of the distribution being closer to power law. The variance, sigma(2), of log spot intensity shows a positive correlation with genome size (in terms of number of genes) and is therefore relatively fixed within some range for a given organism. The measured value of sigma(2) can be significantly smaller than the expected value if the mRNA is extracted from a sample of mixed cell types. Our research demonstrates that useful biological findings may result from analyzing microarray data at the level of entire intensity distributions.

Algorithms↗

Molecular characterization of antigen-induced lung inflammation in a murine model of asthma.

Asthma is one of the foremost contributors to morbidity and mortality in industrialized countries. Our objective was to characterize the acute response to allergen and to identify potentially novel molecular targets for pharmacological intervention in asthma. We therefore designed a study to identify genes whose regulation was altered following ovalbumin (OVA) challenge in the presence and absence of treatment with glucocorticoids in BALB/c mice. RNA was isolated from lungs for gene profiling from 8-week-old sensitized mice, 3 and 18 hours post OVA challenge on days 1, 4, and 7 of aerosol challenge. Taqman (real time RT-PCR) analysis of marker genes indicative of Th2 (IL-4, IL-13), eosinophil (RANTES, eotaxin), Th1/macrophage (IFNgamma) and epithelial cell (MUC5AC) phenotypes were used to characterize responses to allergen challenge. Histological evaluation of lungs from additional challenged animals revealed inflammatory infiltrates on days 4 and 7, but not on day 1 post challenge. We postulate that expression of IL-4, IL-13 and other genes by OVA at day 1 probably reflects activation of resident cells, whereas the fivefold increase in the number of regulated genes at day 7 reflects the contribution of recruited cells. Of the regulated genes, only a subset was counter-regulated by dexamethasone treatment. Although regulated genes included genes in many protein families, herein we report regulation of two proteases whose role in response to OVA challenge has not been characterized. This model will be used to generate disease hypotheses for which may play an important role in initiating disease pathology in this model.

Animals↗