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We describe the Phase II HapMap, which characterizes over 3.1 million human single nucleotide polymorphisms (SNPs) genotyped in 270 individuals from four geographically diverse populations and includes 25-35% of common SNP variation in the populations surveyed. The map is estimated to capture untyped common variation with an average maximum r2 of between(More)
With the advent of dense maps of human genetic variation, it is now possible to detect positive natural selection across the human genome. Here we report an analysis of over 3 million polymorphisms from the International HapMap Project Phase 2 (HapMap2). We used 'long-range haplotype' methods, which were developed to identify alleles segregating in a(More)
Enteric neural crest cells (NCCs) migrate and colonize the entire gut and proliferate and differentiate into neurons and glia of the enteric nervous system in vertebrate embryos. We have investigated the mitogenic and morphogenic functions of Sonic hedgehog (Shh) on enteric NCCs in cell and organ culture. Enteric NCCs expressed Shh receptor Patched and(More)
The quantitative comparison of two or more microarrays can reveal, for example, the distinct patterns of gene expression that define different cellular phenotypes or the genes that are induced in the cellular response to certain stimulations. Normalization of the measured intensities is a prerequisite of such comparisons. However, a fundamental problem in(More)
The major gene for Hirschsprung disease (HSCR) encodes the receptor tyrosine kinase RET. In a study of 690 European- and 192 Chinese-descent probands and their parents or controls, we demonstrate the ubiquity of a >4-fold susceptibility from a C-->T allele (rs2435357: p = 3.9 x 10(-43) in European ancestry; p = 1.1 x 10(-21) in Chinese samples) that(More)
LPS is a main causative agent of septic shock. There is a lack of effective therapies. In vitro studies have shown that uptake of apoptotic cells actively inhibits the secretion by activated macrophages (Mphi) of proinflammatory mediators such as TNF-alpha and that such uptake increases the antiinflammatory and immunosuppressive cytokine TGF-beta. We(More)
Severe acute respiratory syndrome (SARS) is a new infectious disease with a global impact. Understanding its pathogenesis and developing specific diagnostic methods for its early diagnosis are crucial for the effective management and control of this disease. By using proteomic technology, truncated forms of alpha(1)-antitrypsin (TF-alpha(1)-AT) were found(More)
HOX genes from paralogous groups 4 and 5 are particularly relevant to the gut neuromusculature development because these genes are expressed at the splanchnic mesoderm surrounding the gut diverticulum, and at the level of the neural tube from where the vagal neural crest cells (NCCs) originate. In this study, we examined the migration and differentiation of(More)
A semilinear in-slide model is introduced to remove the intensity effect in the scanning process. It is demonstrated that the intensity effect can be estimated accurately and removed effectively. This normalization step is vital for Affymetrix arrays to reveal relevant biological results when comparing gene expression in multiple arrays. The normalized(More)
Hirschsprung's disease (HSCR) is a congenital disorder characterised by the absence of ganglia along variable lengths of the intestine. The RET gene is the major HSCR gene. Reduced penetrance of RET mutations and phenotypic variability suggest the involvement of additional modifying genes in the disease. A RET-dependent modifier locus was mapped to 9q31 in(More)