194 research outputs found
Comprehensive assessment of the hemostatic system in polycystic ovarian syndrome
Polycystic ovarian syndrome (PCOS) affects 12 to 19% of women and has reproductive and metabolicfeatures (endothelial dysfunction, increased diabetes, and cardiovascular risk factors). It also appears to have altered coagulation and fibrinolysis with a prothrombotic state with epidemiological evidence of increased venous thromboembolism. We aimed to comprehensively assess hemostasis in women with PCOS versus control women. In an established case-control cohort of lean, overweight, and obese women with (n = 1 07) and without PCOS (n = 67), with existing measures of plasminogen activator inhibitor 1 (PAI-1 ), asymmetric dimethylarginine (ADMA), hormonal, and metabolic markers, we also assessed prothrombin fragments 1 and 2 (PF1 & 2), plasminogen, tissue plasminogen activator (tPA), and thrombin generation (TG). Higher levels of ADMA (0.70 vs. 0.39 mumol/L, p < 0.01 ), PAI-1 (4.80 vs. 3.66 U/ml, p < 0.01 ), and plasminogen (118.39 vs. 108.46%, p < 0.01) were seen in PCOS versus controls, and persisted after adjustment for age and body mass index (BMI). PF1 & 2 was marginally lower (180.0 vs. 236.0 pmolfl, p 0.05), whereas tPA and TG were not different between groups, after adjustment for age and BMI. Significant relationships were observed between hormonal and metabolic factors with ADMA and PAI-1. We demonstrate impaired fibrinolysis in PCOS. In the context of abnormal endothelial function and known hormonal and metabolic abnormalities, this finding may underpin an increased risk of cardiovascular disease and venous thrombosis in PCOS
Associations of Vitamin D with Inter- and Intra-Muscular Adipose Tissue and Insulin Resistance in Women with and without Polycystic Ovary Syndrome
Low vitamin D and insulin resistance are common in polycystic ovary syndrome (PCOS) and associated with higher inter- and intra-muscular adipose tissue (IMAT). We investigated associations between vitamin D, IMAT and insulin resistance in a cross-sectional study of 40 women with PCOS and 30 women without PCOS, and pre- and post-exercise in a 12-week intervention in 16 overweight participants (10 with PCOS and six without PCOS). A non-classical body mass index (BMI) threshold was used to differentiate lean and overweight women (BMI ≥ 27 kg/m²). Measurements included plasma 25-hydroxyvitamin D (25OHD), insulin resistance (glucose infusion rate (GIR; mg/m²/min), fasting glucose and insulin, and glycated haemoglobin), visceral fat, mid-thigh IMAT (computed tomography) and total body fat (dual-energy X-ray absorptiometry). Women with both PCOS and low 25OHD levels had the lowest GIR (all p < 0.05). Higher IMAT was associated with lower 25OHD (B = -3.95; 95% CI -6.86, -1.05) and GIR (B = -21.3; 95% CI -37.16, -5.44) in women with PCOS. Overweight women with pre-exercise 25OHD ≥30 nmol/L had significant increases in GIR, and decreases in total and visceral fat (all p < 0.044), but no associations were observed when stratified by PCOS status. Women with PCOS and low 25OHD levels have increased insulin resistance which may be partly explained by higher IMAT. Higher pre-training 25OHD levels may enhance exercise-induced changes in body composition and insulin resistance in overweight women
Exercise and insulin resistance in PCOS: muscle insulin signalling and fibrosis
OBJECTIVE:Mechanisms of insulin resistance in polycystic ovary syndrome (PCOS) remain ill-defined, contributing to sub-optimal therapies. Recognising skeletal muscle plays a key role in glucose homeostasis we investigated early insulin signalling, its association with aberrant transforming growth factor β (TGFβ) regulated tissue fibrosis. We also explored the impact of aerobic exercise on these molecular pathways. METHODS:A secondary analysis from a cross-sectional study was undertaken in women with (n=30) or without (n=29) PCOS across lean and overweight BMIs. A subset of participants with (n=8) or without (n=8) PCOS who were overweight completed 12-weeks of aerobic exercise training. Muscle was sampled before and 30 min into a euglycaemic-hyperinsulinaemic clamp pre- and post-training. RESULTS:We found reduced signalling in PCOS of mechanistic target of rapamycin (mTOR). Exercise training augmented but did not completely rescue this signalling defect in women with PCOS. Genes in the TGFβ signalling network were upregulated in skeletal muscle in the overweight women with PCOS but were unresponsive to exercise training except for genes encoding LOX, collagen 1 and 3. CONCLUSIONS:We provide new insights into defects in early insulin signalling, tissue fibrosis, and hyperandrogenism in PCOS-specific insulin resistance in lean and overweight women. PCOS-specific insulin-signalling defects were isolated to mTOR, while gene expression implicated TGFβ ligand regulating a fibrosis in the PCOS-obesity synergy in insulin resistance and altered responses to exercise. Interestingly, there was little evidence for hyperandrogenism as a mechanism for insulin resistance
The Genetics of Polycystic Ovary Syndrome: An Overview of Candidate Gene Systematic Reviews and Genome-Wide Association Studies
Polycystic Ovary Syndrome (PCOS) is a complex condition with mechanisms likely to
involve the interaction between genetics and lifestyle. Familial clustering of PCOS symptoms is
well documented, providing evidence for a genetic contribution to the condition. This overview
aims firstly to systematically summarise the current literature surrounding genetics and PCOS,
and secondly, to assess the methodological quality of current systematic reviews and identify
limitations. Four databases were searched to identify candidate gene systematic reviews, and quality
was assessed with the AMSTAR tool. Genome-wide association studies (GWAS) were identified
by a semi structured literature search. Of the candidate gene systematic reviews, 17 were of high
to moderate quality and four were of low quality. A total of 19 gene loci have been associated
with risk of PCOS in GWAS, and 11 of these have been replicated across two different ancestries.
Gene loci were located in the neuroendocrine, metabolic, and reproductive pathways. Overall,
th
Systematic review and meta-analysis : the prevalence of mental illness in child and adolescent refugees and asylum seekers
Objective
Over half of the world’s refugee population are under the age of 18 years. This systematic review aims to summarise the current body of evidence for the prevalence of mental illness in child and adolescent refugee populations.
Method
Eight electronic databases, grey literature, and Google Scholar were searched for articles from 1 January 2003 to 5 February 2018. Strict inclusion criteria regarding the diagnosis of mental illness were imposed. Study quality was assessed using a template according to study design, and study heterogeneity using I2 statistic. Random effects meta-analyses results were presented given heterogeneity among studies. The protocol for this systematic review was registered with PROSPERO (CRD42016046349).
Results
Eight studies were eligible, involving 779 child and adolescent refugees and asylum seekers, with studies conducted in five countries. The overall prevalence of post-traumatic stress disorder (PTSD) was 22.71% (95% CI 12.79-32.64), depression 13.81% (95% CI 5.96-21.67), and anxiety disorders 15.77% (95% CI 8.04-23.50). Attention-deficit/hyperactivity disorder (ADHD) was 8.6% (1.08-16.12) and oppositional defiant disorder (ODD) was 1.69% (95% CI -0.78 – 4.16). Due to high heterogeneity, further subgroup analyses were conducted.
Conclusion
Refugee and asylum seeker children have high rates of PTSD, depression, and anxiety. Without the serious commitment by health and resettlement services to provide early support to promote mental health, these findings suggest a high proportion of refugee children are at risk of educational disadvantage and poor social integration in host communities, potentially affecting their life course
Epigenetic reprogramming of immune cells in women with PCOS impact genes controlling reproductive function
The origins of the trypanosome genome strains Trypanosoma brucei brucei TREU 927, T. b. gambiense DAL 972, T. vivax Y486 and T. congolense IL3000
The genomes of several tsetse-transmitted African trypanosomes (Trypanosoma brucei brucei, T. b. gambiense, T. vivax, T. congolense) have been sequenced and are available to search online. The trypanosome strains chosen for the genome sequencing projects were selected because they had been well characterised in the laboratory, but all were isolated several decades ago. The purpose of this short review is to provide some background information on the origins and biological characterisation of these strains as a source of reference for future users of the genome data. With high throughput sequencing of many more trypanosome genomes in prospect, it is important to understand the phylogenetic relationships of the genome strains
The effectiveness of high intensity intermittent training on metabolic, reproductive and mental health in women with polycystic ovary syndrome: study protocol for the iHIT- randomised controlled trial
Abstract Background Polycystic ovary syndrome (PCOS) is a reproductive-metabolic condition. Insulin resistance is a hallmark of PCOS and is related to increased hyperandrogenism that drives inherent metabolic, reproductive and psychological features of the syndrome. Insulin resistance in women with PCOS is managed by weight loss, lifestyle interventions (i.e. exercise, diet) and insulin-sensitising medications. This manuscript describes the protocol of our study evaluating the effectiveness of high intensity intermittent training (HIIT) or moderate intensity exercise on cardiometabolic, reproductive and mental health in overweight women with PCOS. Methods/design We will employ a three arm, parallel-group, randomised controlled trial recruiting 60 women diagnosed with PCOS, aged between 18 and 45 years and with a body mass index (BMI) greater than 25 kg/m2. Following screening and baseline testing, women will be randomised by simple randomisation procedure using computer generated sequence allocation to undergo one of two 12-week supervised interventions: either HIIT or moderate intensity exercise (standard supervised exercise), or to standard care [Con] (unsupervised lifestyle advice) at a 1:1:1 allocation ratio. The primary outcome for this trial is to measure the improvements in metabolic health; specifically changes in insulin sensitivity in response to different exercise intensities. Baseline and post-intervention testing include anthropometric measurements, cardiorespiratory fitness testing, reproductive hormone profiles (anti-müllerian hormone and steroid profiles), metabolic health, health-related quality of life and mental health questionnaires and objective and subjective lifestyle monitoring. Reporting of the study will follow the CONSORT statement. Discussion This trial aims to demonstrate the comparative efficacy and maintenance of different exercise intensities to advance the understanding of PCOS management and provide insight into the optimal exercise intensity for improved cardiometabolic outcomes. Secondary outcomes will include the impact of different exercise protocols on reproductive hormone profiles, mental health and health-related quality of life. Trial registration Australian New Zealand Clinical Trials Registry, ACTRN12615000242527. Registered on 17 March 2015
TRY plant trait database - enhanced coverage and open access
Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives
Differential Gene Expression in the Siphonophore Nanomia bijuga (Cnidaria) Assessed with Multiple Next-Generation Sequencing Workflows
We investigated differential gene expression between functionally specialized feeding polyps and swimming medusae in the siphonophore Nanomia bijuga (Cnidaria) with a hybrid long-read/short-read sequencing strategy. We assembled a set of partial gene reference sequences from long-read data (Roche 454), and generated short-read sequences from replicated tissue samples that were mapped to the references to quantify expression. We collected and compared expression data with three short-read expression workflows that differ in sample preparation, sequencing technology, and mapping tools. These workflows were Illumina mRNA-Seq, which generates sequence reads from random locations along each transcript, and two tag-based approaches, SOLiD SAGE and Helicos DGE, which generate reads from particular tag sites. Differences in expression results across workflows were mostly due to the differential impact of missing data in the partial reference sequences. When all 454-derived gene reference sequences were considered, Illumina mRNA-Seq detected more than twice as many differentially expressed (DE) reference sequences as the tag-based workflows. This discrepancy was largely due to missing tag sites in the partial reference that led to false negatives in the tag-based workflows. When only the subset of reference sequences that unambiguously have tag sites was considered, we found broad congruence across workflows, and they all identified a similar set of DE sequences. Our results are promising in several regards for gene expression studies in non-model organisms. First, we demonstrate that a hybrid long-read/short-read sequencing strategy is an effective way to collect gene expression data when an annotated genome sequence is not available. Second, our replicated sampling indicates that expression profiles are highly consistent across field-collected animals in this case. Third, the impacts of partial reference sequences on the ability to detect DE can be mitigated through workflow choice and deeper reference sequencing
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