Are Long-Range Structural Correlations Behind the Aggregration Phenomena of Polyglutamine Diseases?

We have characterized the conformational ensembles of polyglutamine peptides of various lengths (ranging from to ), both with and without the presence of a C-terminal polyproline hexapeptide. For this, we used state-of-the-art molecular dynamics simulations combined with a novel statistical analysis to characterize the various properties of the backbone dihedral angles and secondary structural motifs of the glutamine residues. For (i.e., just above the pathological length for Huntington's disease), the equilibrium conformations of the monomer consist primarily of disordered, compact structures with non-negligible -helical and turn content. We also observed a relatively small population of extended structures suitable for forming aggregates including - and -strands, and - and -hairpins. Most importantly, for we find that there exists a long-range correlation (ranging for at least residues) among the backbone dihedral angles of the Q residues. For polyglutamine peptides below the pathological length, the population of the extended strands and hairpins is considerably smaller, and the correlations are short-range (at most residues apart). Adding a C-terminal hexaproline to suppresses both the population of these rare motifs and the long-range correlation of the dihedral angles. We argue that the long-range correlation of the polyglutamine homopeptide, along with the presence of these rare motifs, could be responsible for its aggregation phenomena

Genital anomalies in Klinefelter's syndrome

10.1159/000106375Hormone Research683150-15

Street-level concentrations of nitrogen dioxide and suspended particulate matter in Hong Kong

The concentrations of respirable suspended particulates (PM10), fine suspended particulates (PM2.5) and nitrogen dioxide (NO2) were measured in various locations over the territory of Hong Kong. In order to study the contributions of these pollutants from motor vehicles and their characteristics, the attention was focused on the roadside, street-level concentrations. A statistical analysis of the sampling results was conducted to obtain general characteristics of the roadside particulate and nitrogen dioxide pollution and to investigate the effects of traffic volume and meteorological factors on the pollution levels. High correlation coeffiCientS are found between PM10, PM2.5 and NO2 concentration.link_to_subscribed_fulltex

An update on the epidemiology of childhood diabetes in Hong Kong

Objectives: To update the incidence of type 1 and type 2 diabetes in children aged <19 years from 1997 to 2007 in Hong Kong. Methods: Retrospective population-based incidence study. Primary ascertainment: reviewing medical records of diabetes patients in all public hospitals. Secondary ascertainment: impractical upon implementation of personal data privacy ordinance in Hong Kong. Results: Type 1 diabetes: Standardised age-adjusted incidence was 2.4/100,000/yr for children aged <15 years. Significant increase in incidence rate was shown (Slope=0.11/100,000/yr; R 2=0.40; p=0.036). There was a significant increase in incidence in 0-4-year age-group. Type 2 diabetes: Standardised age-adjusted incidence was 2.1/100,000/yr for 10-18-year age-group. Significant increase in incidence rate was shown (Slope=0.314/100,000/yr; R 2= 0.711; p=0.001), with a sharp rise after 2004. Conclusions: Standardised age-adjusted incidence of childhood type 1 diabetes remained low while that for type 2 diabetes was newly determined. A definite increase in incidence for both types was shown (1997-2007), with a trend towards younger age of onset.link_to_subscribed_fulltex