56 research outputs found

    Quantitative image mean squared displacement (iMSD) analysis of the dynamics of profilin 1 at the membrane of live cells.

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    Image mean square displacement analysis (iMSD) is a method allowing the mapping of diffusion dynamics of molecules in living cells. However, it can also be used to obtain quantitative information on the diffusion processes of fluorescently labelled molecules and how their diffusion dynamics change when the cell environment is modified. In this paper, we describe the use of iMSD to obtain quantitative data of the diffusion dynamics of a small cytoskeletal protein, profilin 1 (pfn1), at the membrane of live cells and how its diffusion is perturbed when the cells are treated with Cytochalasin D and/or the interactions of pfn1 are modified when its actin and polyphosphoinositide binding sites are mutated (pfn1-R88A). Using total internal reflection fluorescence microscopy images, we obtained data on isotropic and confined diffusion coefficients, the proportion of cell areas where isotropic diffusion is the major diffusion mode compared to the confined diffusion mode, the size of the confinement zones and the size of the domains of dynamic partitioning of pfn1. Using these quantitative data, we could demonstrate a decreased isotropic diffusion coefficient for the cells treated with Cytochalasin D and for the pfn1-R88A mutant. We could also see changes in the modes of diffusion between the different conditions and changes in the size of the zones of pfn1 confinements for the pfn1 treated with Cytochalasin D. All of this information was acquired in only a few minutes of imaging per cell and without the need to record thousands of single molecule trajectories

    Ringing up about breastfeeding: a randomised controlled trial exploring early telephone peer support for breastfeeding (RUBY) - trial protocol

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    BACKGROUND: The risks of not breastfeeding for mother and infant are well established, yet in Australia, although most women initiate breastfeeding many discontinue breastfeeding altogether and few women exclusively breastfeed to six months as recommended by the World Health Organization and Australian health authorities. We aim to determine whether proactive telephone peer support during the postnatal period increases the proportion of infants who are breastfed at six months, replicating a trial previously found to be effective in Canada. DESIGN/METHODS: A two arm randomised controlled trial will be conducted, recruiting primiparous women who have recently given birth to a live baby, are proficient in English and are breastfeeding or intending to breastfeed. Women will be recruited in the postnatal wards of three hospitals in Melbourne, Australia and will be randomised to peer support or to 'usual' care. All women recruited to the trial will receive usual hospital postnatal care and infant feeding support. For the intervention group, peers will make two telephone calls within the first ten days postpartum, then weekly telephone calls until week twelve, with continued contact until six months postpartum. Primary aim: to determine whether postnatal telephone peer support increases the proportion of infants who are breastfed for at least six months. HYPOTHESIS: that telephone peer support in the postnatal period will increase the proportion of infants receiving any breast milk at six months by 10% compared with usual care (from 46% to 56%).Outcome data will be analysed by intention to treat. A supplementary multivariate analysis will be undertaken if there are any baseline differences in the characteristics of women in the two groups which might be associated with the primary outcomes. DISCUSSION: The costs and health burdens of not breastfeeding fall disproportionately and increasingly on disadvantaged groups. We have therefore deliberately chosen trial sites which have a high proportion of women from disadvantaged backgrounds. This will be the first Australian randomised controlled trial to test the effectiveness and cost effectiveness of proactive peer telephone support for breastfeeding. TRIAL REGISTRATION: Australian and New Zealand Clinical Trials Registry ACTRN12612001024831

    Mothers' AdvocateS In the Community (MOSAIC)- non-professional mentor support to reduce intimate partner violence and depression in mothers: a cluster randomised trial in primary care

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    Background : Effective interventions to increase safety and wellbeing of mothers experiencing intimate partner violence (IPV) are scarce. As much attention is focussed on professional intervention, this study aimed to determine the effectiveness of non-professional mentor support in reducing IPV and depression among pregnant and recent mothers experiencing, or at risk of IPV.Methods : MOSAIC was a cluster randomised trial in 106 primary care (maternal and child health nurse and general practitioner) clinics in Melbourne, Australia. 63/106 clinics referred 215 eligible culturally and linguistically diverse women between January 2006 and December 2007. 167 in the intervention (I) arm, and 91 in the comparison (C) arm. 174 (80.9%) were recruited. 133 (76.4%) women (90 I and 43 C) completed follow-up at 12 months.Intervention: 12 months of weekly home visiting from trained and supervised local mothers, (English &amp; Vietnamese speaking) offering non-professional befriending, advocacy, parenting support and referrals.Main outcome measures: Primary outcomes; IPV (Composite Abuse Scale CAS) and depression (Edinburgh Postnatal Depression Scale EPDS); secondary measures included wellbeing (SF-36), parenting stress (PSI-SF) and social support (MOS-SF) at baseline and follow-up.Analysis: Intention-to-treat using multivariable logistic regression and propensity scoring.Results : There was evidence of a true difference in mean abuse scores at follow-up in the intervention compared with the comparison arm (15.9 vs 21.8, AdjDiff -8.67, CI -16.2 to -1.15). There was weak evidence for other outcomes, but a trend was evident favouring the intervention: proportions of women with CAS scores &ge;7, 51/88 (58.4%) vs 27/42 (64.3%) AdjOR 0.47, CI 0.21 to 1.05); depression (EPDS score &ge;13) (19/85, 22% (I) vs 14/43, 33% (C); AdjOR 0.42, CI 0.17 to 1.06); physical wellbeing mean scores (PCS-SF36: AdjDiff 2.79; CI -0.40 to 5.99); mental wellbeing mean scores (MCS-SF36: AdjDiff 2.26; CI -1.48 to 6.00). There was no observed effect on parenting stress. 82% of women mentored would recommend mentors to friends in similar situations.Conclusion : Non-professional mentor mother support appears promising for improving safety and enhancing physical and mental wellbeing among mothers experiencing intimate partner violence referred from primary care.<br /

    Large-Scale Gene-Centric Meta-Analysis across 39 Studies Identifies Type 2 Diabetes Loci

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    To identify genetic factors contributing to type 2 diabetes (T2D), we performed large-scale meta-analyses by using a custom similar to 50,000 SNP genotyping array (the ITMAT-Broad-CARe array) with similar to 2000 candidate genes in 39 multiethnic population-based studies, case-control studies, and clinical trials totaling 17,418 cases and 70,298 controls. First, meta-analysis of 25 studies comprising 14,073 cases and 57,489 controls of European descent confirmed eight established T2D loci at genome-wide significance. In silico follow-up analysis of putative association signals found in independent genome-wide association studies (including 8,130 cases and 38,987 controls) performed by the DIAGRAM consortium identified a T2D locus at genome-wide significance (GATAD2A/CILP2/PBX4; p = 5.7 x 10(-9)) and two loci exceeding study-wide significance (SREBF1, and TH/INS; p <2.4 x 10(-6)). Second, meta-analyses of 1,986 cases and 7,695 controls from eight African-American studies identified study-wide-significant (p = 2.4 x 10(-7)) variants in HMGA2 and replicated variants in TCF7L2 (p = 5.1 x 10(-15)). Third, conditional analysis revealed multiple known and novel independent signals within five T2D-associated genes in samples of European ancestry and within HMGA2 in African-American samples. Fourth, a multiethnic meta-analysis of all 39 studies identified T2D-associated variants in BCL2 (p = 2.1 x 10(-8)). Finally, a composite genetic score of SNPs from new and established T2D signals was significantly associated with increased risk of diabetes in African-American, Hispanic, and Asian populations. In summary, large-scale meta-analysis involving a dense gene-centric approach has uncovered additional loci and variants that contribute to T2D risk and suggests substantial overlap of T2D association signals across multiple ethnic groups

    Profilin: many facets of a small protein

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    Profilin is a ubiquitously expressed protein well known as a key regulator of actin polymerisation. The actin cytoskeleton is involved in almost all cellular processes including motility, endocytosis, metabolism, signal transduction and gene transcription. Hence, profilin’s role in the cell goes beyond its direct and essential function in regulating actin dynamics. This review will focus on the interactions of Profilin 1 and its ligands at the plasma membrane, in the cytoplasm and the nucleus of the cells and the regulation of profilin activity within those cell compartments. We will discuss the interactions of profilin in cell signalling pathways and highlight the importance of the cell context in the multiple functions that this small essential protein has in conjunction with its role in cytoskeletal organisation and dynamics. We will review some of the mechanisms that control profilin expression and the implications of changed expression of profilin in the light of cancer biology and other pathologies

    Perinatal health outcomes of East African immigrant populations in Victoria, Australia:A population based study

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    Crude and adjusted odds ratios with (95 % CI) for selected perinatal health outcomes of East African immigrants and Australian-born women giving birth to singletons at ≥22 weeks of gestation in Victoria, Australia between 1999 and 2007. (DOC 68 kb

    Male-biased sex ratios in Australian migrant populations : a population-based study of 1 191 250 births 1999-2015

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    Background: The naturally occurring male-to-female (M/F) ratio at birth is 1.05. Higher ratios found primarily in countries across Asia have been attributed to prenatal sex selection due to son preference. There is growing evidence that sex-selective practices continue following migration; however, little is known about these practices following migration to Australia. Methods: In this population-based study we assessed M/F ratios at birth per mother’s country of birth for all registered births 1999–2015 in Victoria, Australia (n = 1 191 250). We also compared the M/F ratio among births to mothers born elsewhere to that of mothers born in Australia, stratified by time period and parity. Results: Compared with the naturally occurring M/F ratio as well as to the M/F ratio among births to mothers born in Australia, there was an increased ratio of male births to mothers born in India, China and South-East Asia, particularly at higher parities and in more recent time periods (elevated M/F ratios ranged from 1·079 to 1·248, relative risks of male birth ranged from 1·012 to 1·084 with confidence intervals between 1·001 and 1·160 and P-values between 0·005 and 0·039). The most male-biased sex ratios were found among multiple births to Indian-born mothers, and parity of two or more births to Indian and Chinese-born mothers in 2011–15. Conclusions: The male-biased sex ratios observed in this study indicate that prenatal sex selection may be continuing following migration to Australia from countries where these practices have been documented. The excess of males among multiple births raises the question as to what role assisted reproduction plays. Findings also suggest that systematic discrimination against females starts in the womb
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