Effects of increasing Mg++ ion concentration on the PKU monitoring assay.

Inaccuracies in a commonly used bacterial inhibition assay for blood phenylalanine levels arise when the Mg++ ion concentration in the assay medium is increased. This has practical implications in the diagnosis and management of phenylketonuria.     

T-cell receptor delta gene rearrangements in early thymocytes

The T-cell receptor delta-chain variable region can be assembled from as many as four distinct gene segments, V, D1, D2 and J, more than any other antigen-receptor gene. In fetal thymocytes V----D joinings are as common as D----J or VDJ rearrangements and one V gene segment predominates. Analysis of rearrangements at TCR gamma and delta loci during fetal ontogeny suggests abrupt changes and possible coordinate control in the rearrangement and expression of these loci.     

Can a myosin molecule bind to two actin filaments?

It is suggested that in striated muscles the two heads of one myosin molecule are able to interact with different actin filaments. This would provide a simple explanation for the appearance and arrangement of cross-bridges in insect flight muscle in rigor.     

Zeitgeber induced modulation of activity patterns in nocturnal mammals (Chiroptera)

Summary Changing the L:D intensity ratio of a synchronizing light-dark regime leads to characteristic modulations of the activity pattern of 5 Chiroptera species. These modulations fit the predictions ofWever's oscillator model.Supported by a grant from the Deutsche Forschungsgemeinschaft (No. Er 59, 1–4).     

Comparison of genome degradation in Paratyphi A and Typhi, human-restricted serovars of Salmonella enterica that cause typhoid

Salmonella enterica serovars often have a broad host range, and some cause both gastrointestinal and systemic disease. But the serovars Paratyphi A and Typhi are restricted to humans and cause only systemic disease. It has been estimated that Typhi arose in the last few thousand years. The sequence and microarray analysis of the Paratyphi A genome indicates that it is similar to the Typhi genome but suggests that it has a more recent evolutionary origin. Both genomes have independently accumulated many pseudogenes among their approximately 4,400 protein coding sequences: 173 in Paratyphi A and approximately 210 in Typhi. The recent convergence of these two similar genomes on a similar phenotype is subtly reflected in their genotypes: only 30 genes are degraded in both serovars. Nevertheless, these 30 genes include three known to be important in gastroenteritis, which does not occur in these serovars, and four for Salmonella-translocated effectors, which are normally secreted into host cells to subvert host functions. Loss of function also occurs by mutation in different genes in the same pathway (e.g., in chemotaxis and in the production of fimbriae).     

Meta-analysis of genome-wide association studies of asthma in ethnically diverse North American populations

Asthma is a common disease with a complex risk architecture including both genetic and environmental factors. We performed a meta-analysis of North American genome-wide association studies of asthma in 5,416 individuals with asthma (cases) including individuals of European American, African American or African Caribbean, and Latino ancestry, with replication in an additional 12,649 individuals from the same ethnic groups. We identified five susceptibility loci. Four were at previously reported loci on 17q21, near IL1RL1, TSLP and IL33, but we report for the first time, to our knowledge, that these loci are associated with asthma risk in three ethnic groups. In addition, we identified a new asthma susceptibility locus at PYHIN1, with the association being specific to individuals of African descent (P = 3.9 × 10(-9)). These results suggest that some asthma susceptibility loci are robust to differences in ancestry when sufficiently large samples sizes are investigated, and that ancestry-specific associations also contribute to the complex genetic architecture of asthma.     

杭州湾大通道和港口建设现状分析及战略构思——系列研究之一

在杭州湾大通道及港口建设对宁波地区经济发展影响的系统分析中，率先分析杭州湾大通道建设的依据、设计规划和意义，以及宁波建设的现状，并进一步研究杭州湾大通道与宁波港之间建设和发展中的协调关系，从而提出和论证了杭州湾大通道和港口建设的战略构思，供决策部门参考。