Protein interactions in Xenopus germ plasm RNP particles

Hermes is an RNA-binding protein that we have previously reported to be found in the ribonucleoprotein (RNP) particles of Xenopus germ plasm, where it is associated with various RNAs, including that encoding the germ line determinant Nanos1. To further define the composition of these RNPs, we performed a screen for Hermes-binding partners using the yeast two-hybrid system. We have identified and validated four proteins that interact with Hermes in germ plasm: two isoforms of Xvelo1 (a homologue of zebrafish Bucky ball) and Rbm24b and Rbm42b, both RNA-binding proteins containing the RRM motif. GFP-Xvelo fusion proteins and their endogenous counterparts, identified with antisera, were found to localize with Hermes in the germ plasm particles of large oocytes and eggs. Only the larger Xvelo isoform was naturally found in the Balbiani body of previtellogenic oocytes. Bimolecular fluorescence complementation (BiFC) experiments confirmed that Hermes and the Xvelo variants interact in germ plasm, as do Rbm24b and 42b. Depletion of the shorter Xvelo variant with antisense oligonucleotides caused a decrease in the size of germ plasm aggregates and loosening of associated mitochondria from these structures. This suggests that the short Xvelo variant, or less likely its RNA, has a role in organizing and maintaining the integrity of germ plasm in Xenopus oocytes. While GFP fusion proteins for Rbm24b and 42b did not localize into germ plasm as specifically as Hermes or Xvelo, BiFC analysis indicated that both interact with Hermes in germ plasm RNPs. They are very stable in the face of RNA depletion, but additive effects of combinations of antisense oligos suggest they may have a role in germ plasm structure and may influence the ability of Hermes protein to effectively enter RNP particles

Testing for vitamin D and other trends in the clinical management of osteoporosis

This descriptive paper identifies some salient trends in the Australian management of osteoporosis. Changes in pharmaceutical consumption and medical utilisation are analysed. The total national consumption of four pharmaceuticals is estimated. From 2001 to 2011, the consumption of bisphosphonates and vitamin D increased. After 2006, the management rate for osteoporosis decreased. Purpose: During the first decade of the millennia, the total cost of vitamin D tests has increased significantly within many health care jurisdictions worldwide. Australia reports a 100-fold increase. Legitimately, concerns regarding the economic effectiveness of this test exist. The purpose of this paper is to identify what other salient clinical trends could affect the efficacy of this test when treating osteoporosis. Methods: Longitudinal data from two Australian datasets are analysed. The first are data obtained from Medicare Australia, which report pharmaceutical consumption. The second are data obtained from a national survey of general practitioners. Results: The management of osteoporosis has been characterised by a movement away from single to combination formularies. The consumption of calcium carbonate has declined, and the use of bisphosphonates has increased. While the gross consumption of risedronate increased steadily over the decade (8.4 to 186.5 kg), the consumption of alendronate declined after 2007. The consumption of vitamin D (over-the-counter and prescription) has increased from 0.58 to 2.8 kg over the decade. While prescription vitamin D comprised just 10 % of the total, its consumption has undergone a 20-fold increase since 2006. Importantly, we can also report that the management of osteoporosis by Australia's general practitioners increased steadily until 2007-2008, before declining by 36 %. Conclusions: Further research is required to determine possible casual relationships that may exist between these data. Until a formal economic evaluation of vitamin D testing in this clinical setting is completed, no conclusions regarding its economic effectiveness should be drawn

Recent applications of mineral magnetic methods in sediment pollution studies : a review

This paper reviews recent progress in applying mineral magnetic methods in sediment pollution studies. Such applications include its use as a dating marker, as a proxy for heavy metal concentrations and to trace metal pollutant dispersal. The mineral magnetic method has been found to be a promising tool in a wide range of sediment metal pollution studies. However, its use as a proxy of heavy metal concentrations is not always straightforward. This reflects the potentially mixed origins of magnetic minerals in sediments which may have an anthropogenic, natural or mixed source. Furthermore, anthropogenic magnetic particles may not have a common source with heavy metals. The possible linkage between magnetic minerals and heavy metals is discussed. The role of sorting, sorption/desorption and post-depositional diagenesis on the magnetic mineral-heavy metal linkage is highlighted as still requiring careful consideration. It is suggested that detailed characterisation of magnetic mineralogy using combined magnetic, geochemical and mineralogical methods is critical to the optimization of sediment pollution studies using a mineral magnetic approach

Assessment of vitamin D and its association with cardiovascular disease risk factors in an adult migrant population: An audit of patient records at a Community Health Centre in Kensington, Melbourne, Australia

Background: Vitamin D deficiency is a global public health problem associated with increased risk of cardio-metabolic diseases and osteoarthritis. Migrants with dark skin settled in temperate climates are at greater risk of both vitamin D deficiency and cardiovascular diseases. This study aims to identify the risk of vitamin D deficiency and associations with cardiovascular disease in a migrant population in Australia. Methods: An audit was carried out at a Community Health Service in Kensington, Melbourne which, services a large migrant population. Data from the clinical records of all adults who visited the medical centre at least once during the period from 1st January 2010 to 31st December 2012 was extracted. The future (10 year) coronary heart disease risk was estimated using Framingham Risk Score. Results: The centre has given higher priority to vitamin D testing in migrants, those middle-aged, females and those with diabetes and osteoarthritis. Migrants from countries located in lower latitude regions (Latitude N230 to S230) were 1.48 (95% C.I. 1.32-1.65) times more likely to develop vitamin D deficiency post migration and 0.44 (95% C.I. 0.31-0.62) times less likely to have a >15% 10-year risk of coronary heart disease when compared to their Australian-born counterparts. Conclusions: Adherence to a high risk strategy for vitamin D testing was observed in the centre. Pre-migration latitude is an important factor for vitamin D deficiency (lower the latitude higher the risk) and in predicting future risk of cardiovascular disease in migrants. These findings suggest that a targeted approach for vitamin D testing, including zone of origin might better identify individuals at higher risk of both vitamin D deficiency and cardiovascular disease