University of Queensland

About: University of Queensland is a education organization based out in Brisbane, Queensland, Australia. It is known for research contribution in the topics: Population & Poison control. The organization has 51138 authors who have published 155721 publications receiving 5717659 citations. The organization is also known as: UQ & The University of Queensland.

Effect of obesity on survival of women with breast cancer: systematic review and meta-analysis

Abstract: Obesity is a risk factor for the development of new cases of breast cancer and also affects survival in women who have already been diagnosed with breast cancer. Early studies of obesity and breast cancer survival have been summarised in two meta-analyses, but the latest of these only included studies that recruited women diagnosed as recently as 1991. The primary aim of this study was to conduct a meta-analysis that included the more recent studies. A systematic search of MEDLINE, EMBASE and CINAHL was conducted to identify original data evaluating the effects of obesity on survival in newly diagnosed breast cancer patients. Adjusted hazard ratios (HR) from individual studies were pooled using a random effects model. A series of pre-specified sensitivity analyses were conducted on factors such as overall versus breast cancer survival and treatment versus observational cohort. The meta-analysis included 43 studies that enrolled women diagnosed with breast cancer between 1963 and 2005. Sample size ranged from 100 to 424168 (median 1192). The meta-analysis showed poorer survival among obese compared with non-obese women with breast cancer, which was similar for overall (HR = 1.33; 95% confidence interval (CI): 1.21, 1.47) and breast cancer specific survival (HR = 1.33; 95% CI: 1.19, 1.50). The survival differential varied only slightly, depending on whether body mass index (1.33; 1.21, 1.47) or waist-hip ratio (1.31; 1.08, 1.58) was used as the measure of obesity. There were larger differences by whether the woman was pre-menopausal (1.47) or post-menopausal (1.22); whether the cohort included women diagnosed before (1.31) or after 1995 (1.49); or whether the women were in a treatment (1.22) or observational cohort (1.36), but none of the differences were statistically significant. Women with breast cancer, who are obese, have poorer survival than women with breast cancer, who are not obese. However, no study has elucidated the causal mechanism and there is currently no evidence that weight loss after diagnosis improves survival. Consequently, there is currently no reason to place the additional burden of weight loss on women already burdened with a diagnosis of cancer. Further research should concentrate on assessing whether factors such as diabetes or type of chemotherapy modify the obesity effect and on understanding the causal mechanism, in particular the role of relative under-dosing.

An atlas of human long non-coding RNAs with accurate 5′ ends

Abstract: Long non-coding RNAs (lncRNAs) are largely heterogeneous and functionally uncharacterized. Here, using FANTOM5 cap analysis of gene expression (CAGE) data, we integrate multiple transcript collections to generate a comprehensive atlas of 27,919 human lncRNA genes with high-confidence 5' ends and expression profiles across 1,829 samples from the major human primary cell types and tissues. Genomic and epigenomic classification of these lncRNAs reveals that most intergenic lncRNAs originate from enhancers rather than from promoters. Incorporating genetic and expression data, we show that lncRNAs overlapping trait-associated single nucleotide polymorphisms are specifically expressed in cell types relevant to the traits, implicating these lncRNAs in multiple diseases. We further demonstrate that lncRNAs overlapping expression quantitative trait loci (eQTL)-associated single nucleotide polymorphisms of messenger RNAs are co-expressed with the corresponding messenger RNAs, suggesting their potential roles in transcriptional regulation. Combining these findings with conservation data, we identify 19,175 potentially functional lncRNAs in the human genome.

Phylogenomics of the Reproductive Parasite Wolbachia pipientis wMel: A Streamlined Genome Overrun by Mobile Genetic Elements

Abstract: The complete sequence of the 1,267,782 bp genome of Wolbachia pipientis wMel, an obligate intracellular bacteria of Drosophila melanogaster, has been determined. Wolbachia, which are found in a variety of invertebrate species, are of great interest due to their diverse interactions with different hosts, which range from many forms of reproductive parasitism to mutualistic symbioses. Analysis of the wMel genome, in particular phylogenomic comparisons with other intracellular bacteria, has revealed many insights into the biology and evolution of wMel and Wolbachia in general. For example, the wMel genome is unique among sequenced obligate intracellular species in both being highly streamlined and containing very high levels of repetitive DNA and mobile DNA elements. This observation, coupled with multiple evolutionary reconstructions, suggests that natural selection is somewhat inefficient in wMel, most likely owing to the occurrence of repeated population bottlenecks. Genome analysis predicts many metabolic differences with the closely related Rickettsia species, including the presence of intact glycolysis and purine synthesis, which may compensate for an inability to obtain ATP directly from its host, as Rickettsia can. Other discoveries include the apparent inability of wMel to synthesize lipopolysaccharide and the presence of the most genes encoding proteins with ankyrin repeat domains of any prokaryotic genome yet sequenced. Despite the ability of wMel to infect the germline of its host, we find no evidence for either recent lateral gene transfer between wMel and D. melanogaster or older transfers between Wolbachia and any host. Evolutionary analysis further supports the hypothesis that mitochondria share a common ancestor with the alpha-Proteobacteria, but shows little support for the grouping of mitochondria with species in the order Rickettsiales. With the availability of the complete genomes of both species and excellent genetic tools for the host, the wMel-D. melanogaster symbiosis is now an ideal system for studying the biology and evolution of Wolbachia infections.

Ras proteins: different signals from different locations

Abstract: Ras signalling has classically been thought to occur exclusively at the inner surface of a relatively uniform plasma membrane. Recent studies have shown that Ras proteins interact dynamically with specific microdomains of the plasma membrane as well as with other internal cell membranes. These different membrane microenvironments modulate Ras signal output and highlight the complex interplay between Ras location and function.