282 research outputs found

    Female economic dependence and the morality of promiscuity

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    This article is made available through the Brunel Open Access Publishing Fund. Copyright @ The Author(s) 2014.In environments in which female economic dependence on a male mate is higher, male parental investment is more essential. In such environments, therefore, both sexes should value paternity certainty more and thus object more to promiscuity (because promiscuity undermines paternity certainty). We tested this theory of anti-promiscuity morality in two studies (N = 656 and N = 4,626) using U.S. samples. In both, we examined whether opposition to promiscuity was higher among people who perceived greater female economic dependence in their social network. In Study 2, we also tested whether economic indicators of female economic dependence (e.g., female income, welfare availability) predicted anti-promiscuity morality at the state level. Results from both studies supported the proposed theory. At the individual level, perceived female economic dependence explained significant variance in anti-promiscuity morality, even after controlling for variance explained by age, sex, religiosity, political conservatism, and the anti-promiscuity views of geographical neighbors. At the state level, median female income was strongly negatively related to anti-promiscuity morality and this relationship was fully mediated by perceived female economic dependence. These results were consistent with the view that anti-promiscuity beliefs may function to promote paternity certainty in circumstances where male parental investment is particularly important

    The Critical Role of Supervision in Retaining Staff in Obstetric Services: A Three Country Study

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    Millennium Development Goal (MDG) 5 commits us to reducing maternal mortality rates by three quarters and MDG 4 commits us to reducing child mortality by two-thirds between 1990 and 2015. In order to reach these goals, greater access to basic emergency obstetric care (EmOC) as well as comprehensive EmOC which includes safe Caesarean section, is needed.. The limited capacity of health systems to meet demand for obstetric services has led several countries to utilize mid-level cadres as a substitute to more extensively trained and more internationally mobile healthcare workers. Although this does provide greater capacity for service delivery, concern about the performance and motivation of these workers is emerging. We propose that poor leadership characterized by inadequate and unstructured supervision underlies much of the dissatisfaction and turnover that has been shown to exist amongst these mid-level healthcare workers and indeed health workers more generally. To investigate this, we conducted a large-scale survey of 1,561 mid-level cadre healthcare workers (health workers trained for shorter periods to perform specific tasks e.g. clinical officers) delivering obstetric care in Malawi, Tanzania, and Mozambique. Participants indicated the primary supervision method used in their facility and we assessed their job satisfaction and intentions to leave their current workplace. In all three countries we found robust evidence indicating that a formal supervision process predicted high levels of job satisfaction and low intentions to leave. We find no evidence that facility level factors modify the link between supervisory methods and key outcomes. We interpret this evidence as strongly supporting the need to strengthen leadership and implement a framework and mechanism for systematic supportive supervision. This will promote better job satisfaction and improve the retention and performance of obstetric care workers, something which has the potential to improve maternal and neonatal outcomes in the countdown to 2015

    Breast cancer risk perception: what do we know and understand?

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    Women's perceptions of breast cancer risk are largely inaccurate and are often associated with high levels of anxiety about cancer. There are interesting cultural differences that are not well researched. Genetic risk counselling significantly improves accuracy of women's perceptions of risk, but not necessarily to the correct level. Reasons for this are unclear, but may relate to personal beliefs about susceptibility and to problems or variations in risk communication. Research into the impact of demographic and psychological factors on risk perception has been inconclusive. An understanding of the process of developing a perception of risk would help to inform risk counselling strategies. This is important, because knowledge of risk is needed both for appropriate health care decision making and to reassure women who are not at increased risk

    Novel selective antagonist radioligands for the pharmacological study of A2B adenosine receptors

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    The adenosine A2B receptor is the least well characterized of the four adenosine subtypes due to the lack of potent and selective agonists and antagonists. Despite the widespread distribution of A2B receptor mRNA, little information is available with regard to their function. The characterization of A2B receptors, through radioligand binding studies, has been performed, until now, by using low-affinity and non-selective antagonists like 1,3-dipropyl-8-cyclopentylxanthine ([3H]DPCPX),(4-(2-[7-amino-2-(2-furyl)-[1,2,4]triazolo-[2,3-a][1,3,5]triazin-5-ylamino]ethyl)-phenol ([3H]ZM 241385) and 3-(3,4-aminobenzyl)-8-(4-oxyacetate)phenyl-1-propyl-xanthine ([125I]ABOPX). Recently, high-affinity radioligands for A2B receptors, [N-(4-cyanophenyl)-2-[4-(2,3,6,7-tetrahydro-2,6-dioxo-1,3-dipropyl-1H-purin-8-yl)-phenoxy]acetamide ([3H]MRS 1754), N-(2-(2-Phenyl-6-[4-(2,2,3,3-tetratritrio-3-phenylpropyl)-piperazine-1-carbonyl]-7H-pyrrolo[2,3-d]pyrimidin-4-ylamino)-ethyl)-acetamide ([3H]OSIP339391) and N-benzo[1,3]dioxol-5-yl-2-[5-(1,3-dipropyl-2,6-dioxo-2,3,6,7-tetrahydro-1H-purin-8-yl)-1-methyl-1H-pyrazol-3-yloxy]-acetamide] ([3H]MRE 2029F20), have been introduced. This minireview offers an overview of these recently developed radioligands and the most important applications of drugs towards A2B receptors

    Lack of effect of adenosine on the function of rodent osteoblasts and osteoclasts in vitro

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    Extracellular ATP, signalling through P2 receptors, exerts well-documented effects on bone cells, inhibiting mineral deposition by osteoblasts and stimulating the formation and resorptive activity of osteoclasts. The aims of this study were to determine the potential osteotropic effects of adenosine, the hydrolysis product of ATP, on primary bone cells in vitro. We determined the effect of exogenous adenosine on (1) the growth, alkaline phosphatase (TNAP) activity and bone-forming ability of osteoblasts derived from the calvariae of neonatal rats and mice and the marrow of juvenile rats and (2) the formation and resorptive activity of osteoclasts from juvenile mouse marrow. Reverse transcription polymerase chain reaction (RT-PCR) analysis showed marked differences in the expression of P1 receptors in osteoblasts from different sources. Whilst mRNA for the A1 and A2B receptors was expressed by all primary osteoblasts, A2A receptor expression was limited to rat bone marrow and mouse calvarial osteoblasts and the A3 receptor to rat bone marrow osteoblasts. We found that adenosine had no detectable effects on cell growth, TNAP activity or bone formation by rodent osteoblasts in vitro. The analogue 2-chloroadenosine, which is hydrolysed more slowly than adenosine, had no effects on rat or mouse calvarial osteoblasts but increased TNAP activity and bone formation by rat bone marrow osteoblasts by 30–50 % at a concentration of 1 μM. Osteoclasts were found to express the A2A, A2B and A3 receptors; however, neither adenosine (≤100 μM) nor 2-chloroadenosine (≤10 μM) had any effect on the formation or resorptive activity of mouse osteoclasts in vitro. These results suggest that adenosine, unlike ATP, is not a major signalling molecule in the bone

    Progress in the discovery of selective, high affinity A2B adenosine receptor antagonists as clinical candidates

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    The selective, high affinity A2B adenosine receptor (AdoR) antagonists that were synthesized by several research groups should aid in determining the role of the A2B AdoR in inflammatory diseases like asthma or rheumatoid arthritis (RA) and angiogenic diseases like diabetic retinopathy or cancer. CV Therapeutics scientists discovered the selective, high affinity A2B AdoR antagonist 10, a 8-(4-pyrazolyl)-xanthine derivative [CVT-6883, Ki(hA2B) = 22 nM; Ki(hA1) = 1,940 nM; Ki(hA2A) = 3,280; and Ki(hA3) = 1,070 nM] that has favorable pharmacokinetic (PK) properties (t1/2 = 4 h and F > 35% rat). Compound 10 demonstrated functional antagonism at the A2B AdoR (KB = 6 nM) and efficacy in a mouse model of asthma. In two phase 1 clinical trials, CVT-6883 was found to be safe, well tolerated, and suitable for once daily dosing. A second compound 20, 8-(5-pyrazolyl)-xanthine, has been nominated for development from Baraldi’s group in conjunction with King Pharmaceuticals that has favorable A2B AdoR affinity and selectivity [Ki(hA2B) = 5.5 nM; Ki(hA1) > 1,000 nM; Ki(hA2A) > 1,000; and Ki(hA3) > 1,000 nM], and it has been demonstrated to be a functional antagonist. A third compound 32, a 2-aminopyrimidine, from the Almirall group has high A2B AdoR affinity and selectivity [Ki(hA2B) = 17 nM; Ki(hA1) > 1,000 nM; Ki(hA2A) > 2,500; and Ki(hA3) > 1,000 nM], and 32 has been moved into preclinical safety testing. Since three highly selective, high affinity A2B AdoR antagonists have been nominated for development with 10 (CVT-6883) being the furthest along in the development process, the role of the A2B AdoR in various disease states will soon be established

    Creatine ingestion augments dietary carbohydrate mediated muscle glycogen supercomposition during the initial 24 hrs of recovery following prolonged exhaustive exercise in humans

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    Muscle glycogen availability can limit endurance exercise performance. We previously demonstrated 5 days of creatine (Cr) and carbohydrate (CHO) ingestion augmented post-exercise muscle glycogen storage compared to CHO feeding alone in healthy volunteers. Here we aimed to characterise the time-course of this Cr-induced response under more stringent and controlled experimental conditions and identify potential mechanisms underpinning this phenomenon. Fourteen healthy, male volunteers cycled to exhaustion at 70% VO2peak. Muscle biopsies were obtained at rest immediately post-exercise and after 1, 3 and 6 days of recovery, during which Cr or placebo supplements (20g.day-1) were ingested along with a prescribed high CHO diet (37.5 kcal.kg body mass-1.day-1, >80% calories CHO). Oral-glucose tolerance tests (oral-GTT) were performed pre-exercise and after 1, 3 and 6 days of Cr and placebo supplementation. Exercise depleted muscle glycogen content to the same extent in both treatment groups. Creatine supplementation increased muscle total-Cr, free-Cr and phosphocreatine (PCr) content above placebo following 1, 3 and 6 days of supplementation (all P<0.05). Creatine supplementation also increased muscle glycogen content noticeably above placebo after 1 day of supplementation (P<0.05), which was sustained thereafter. This study confirmed dietary Cr augments post-exercise muscle glycogen super-compensation, and demonstrates this occurred during the initial 24 h of post-exercise recovery (when muscle total-Cr had increased by <10%). This marked response ensued without apparent treatment differences in muscle insulin sensitivity (oral-GTT, muscle GLUT4 mRNA), osmotic stress (muscle c-fos and HSP72 mRNA) or muscle cell volume (muscle water content) responses, such that another mechanism must be causative

    Common Inherited Variation in Mitochondrial Genes Is Not Enriched for Associations with Type 2 Diabetes or Related Glycemic Traits

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    Mitochondrial dysfunction has been observed in skeletal muscle of people with diabetes and insulin-resistant individuals. Furthermore, inherited mutations in mitochondrial DNA can cause a rare form of diabetes. However, it is unclear whether mitochondrial dysfunction is a primary cause of the common form of diabetes. To date, common genetic variants robustly associated with type 2 diabetes (T2D) are not known to affect mitochondrial function. One possibility is that multiple mitochondrial genes contain modest genetic effects that collectively influence T2D risk. To test this hypothesis we developed a method named Meta-Analysis Gene-set Enrichment of variaNT Associations (MAGENTA; http://www.broadinstitute.org/mpg/magenta). MAGENTA, in analogy to Gene Set Enrichment Analysis, tests whether sets of functionally related genes are enriched for associations with a polygenic disease or trait. MAGENTA was specifically designed to exploit the statistical power of large genome-wide association (GWA) study meta-analyses whose individual genotypes are not available. This is achieved by combining variant association p-values into gene scores and then correcting for confounders, such as gene size, variant number, and linkage disequilibrium properties. Using simulations, we determined the range of parameters for which MAGENTA can detect associations likely missed by single-marker analysis. We verified MAGENTA's performance on empirical data by identifying known relevant pathways in lipid and lipoprotein GWA meta-analyses. We then tested our mitochondrial hypothesis by applying MAGENTA to three gene sets: nuclear regulators of mitochondrial genes, oxidative phosphorylation genes, and ∼1,000 nuclear-encoded mitochondrial genes. The analysis was performed using the most recent T2D GWA meta-analysis of 47,117 people and meta-analyses of seven diabetes-related glycemic traits (up to 46,186 non-diabetic individuals). This well-powered analysis found no significant enrichment of associations to T2D or any of the glycemic traits in any of the gene sets tested. These results suggest that common variants affecting nuclear-encoded mitochondrial genes have at most a small genetic contribution to T2D susceptibility

    Analysis of protein-coding genetic variation in 60,706 humans

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    Large-scale reference data sets of human genetic variation are critical for the medical and functional interpretation of DNA sequence changes. Here we describe the aggregation and analysis of high-quality exome (protein-coding region) DNA sequence data for 60,706 individuals of diverse ancestries generated as part of the Exome Aggregation Consortium (ExAC). This catalogue of human genetic diversity contains an average of one variant every eight bases of the exome, and provides direct evidence for the presence of widespread mutational recurrence. We have used this catalogue to calculate objective metrics of pathogenicity for sequence variants, and to identify genes subject to strong selection against various classes of mutation; identifying 3,230 genes with near-complete depletion of predicted protein-truncating variants, with 72% of these genes having no currently established human disease phenotype. Finally, we demonstrate that these data can be used for the efficient filtering of candidate disease-causing variants, and for the discovery of human 'knockout' variants in protein-coding genes
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