Crystallization and preliminary X-ray diffraction studies of Drosophila melanogaster Gαo-subunit of heterotrimeric G protein in complex with the RGS domain of CG5036.

Regulator of G-protein signalling (RGS) proteins negatively regulate heterotrimeric G-protein signalling through their conserved RGS domains. RGS domains act as GTPase-activating proteins, accelerating the GTP hydrolysis rate of the activated form of Gα-subunits. Although omnipresent in eukaryotes, RGS proteins have not been adequately analysed in non-mammalian organisms. The Drosophila melanogaster Gαo-subunit and the RGS domain of its interacting partner CG5036 have been overproduced and purified; the crystallization of the complex of the two proteins using PEG 4000 as a crystallizing agent and preliminary X-ray crystallographic analysis are reported. Diffraction data were collected to 2.0 Å resolution using a synchrotron-radiation source.

Exposure of the Swiss population by medical x-rays: 2008 review.

Nationwide surveys on radiation dose to the population from medical radiology are recommended in order to follow the trends in population exposure and ensure radiation protection. The last survey in Switzerland was conducted in 1998, and the annual effective dose from medical radiology was estimated to be 1 mSv y(-1) per capita. The purpose of this work was to follow the trends in diagnostic radiology between 1998 and 2008 in Switzerland and determine the contribution of different modalities and types of examinations to the collective effective dose from medical x-rays. For this reason, an online database (www.raddose.ch) was developed. All healthcare providers who hold a license to run an x-ray unit in the country were invited to participate in the survey. More than 225 examinations, covering eight radiological modalities, were included in the survey. The average effective dose for each examination was reassessed. Data from about 3,500 users were collected (42% response rate). The survey showed that the annual effective dose was 1.2 mSv/capita in 2008. The most frequent examinations are conventional and dental radiographies (88%). The contribution of computed tomography was only 6% in terms of examination frequency but 68% in terms of effective dose. The comparison with other countries showed that the effective dose per capita in Switzerland was in the same range as in other countries with similar healthcare systems, although the annual number of examinations performed in Switzerland was higher.