119 research outputs found

    A systematic review of randomised controlled trials investigating the efficacy and safety of testosterone therapy for female sexual dysfunction in postmenopausal women

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    The clinical sequelae of oestrogen deficiency during menopause are undoubted. However, the pathophysiological role of testosterone during the menopause is less clear. Several randomised, placebo-controlled clinical trials suggest that testosterone therapy improves sexual function in post-menopausal women. Some studies suggest that testosterone therapy has additional effects which include increased bone mineral density and decreased serum high density lipoprotein (HDL) cholesterol. Furthermore, the long-term safety profile of testosterone therapy in post-menopausal women is not clear. This article will provide a concise and critical summary of the literature, to guide clinicians treating post-menopausal women. This article is protected by copyright. All rights reserved

    Alzheimer's disease markers in the aged sheep (Ovis aries)

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    This study reports the identification and characterization of markers of Alzheimer's disease (AD) in aged sheep (Ovis aries) as a preliminary step toward making a genetically modified large animal model of AD. Importantly, the sequences of key proteins involved in AD pathogenesis are highly conserved between sheep and human. The processing of the amyloid-β (Aβ) protein is conserved between sheep and human, and sheep Aβ1–42/Aβ1–40 ratios in cerebrospinal fluid (CSF) are also very similar to human. In addition, total tau and neurofilament light levels in CSF are comparable with those found in human. The presence of neurofibrillary tangles in aged sheep brain has previously been established; here, we report for the first time that plaques, the other pathologic hallmark of AD, are also present in the aged sheep brain. In summary, the biological machinery to generate the key neuropathologic features of AD is conserved between the human and sheep, making the sheep a good candidate for future genetic manipulation to accelerate the condition for use in pathophysiological discovery and therapeutic testing

    Bottom-Up Assembly of Hydrogels from Bacteriophage and Au Nanoparticles: The Effect of Cis- and Trans-Acting Factors

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    Hydrogels have become a promising research focus because of their potential for biomedical application. Here we explore the long-range, electrostatic interactions by following the effect of trans-acting (pH) and cis-acting factors (peptide mutation) on the formation of Au-phage hydrogels. These bioinorganic hydrogels can be generated from the bottom-up assembly of Au nanoparticles (Au NP) with either native or mutant bacteriophage (phage) through electrostatic interaction of the phage pVIII major capsid proteins (pVIII). The cis-acting factor consists of a peptide extension displayed on the pVIII that mutates the phage. Our results show that pH can dictate the direct-assembly and stability of Au-phage hydrogels in spite of the differences between the native and the mutant pVIII. The first step in characterizing the interactions of Au NP with phage was to generate a molecular model that identified the charge distribution and structure of the native and mutant pVIII. This model indicated that the mutant peptide extension carried a higher positive charge relative to the native pVIII at all pHs. Next, by monitoring the Au-phage interaction by means of optical microscopy, elastic light scattering, fractal dimension analysis as well as Uv-vis and surface plasmon resonance spectroscopy, we show that the positive charge of the mutant peptide extension favors the opposite charge affinity between the phage and Au NP as the pH is decreased. These results show the versatility of this assembly method, where the stability of these hydrogels can be achieved by either adjusting the pH or by changing the composition of the phage pVIII without the need of phage display libraries

    Immediate thoracotomy for penetrating injuries: Ten years' experience at a Dutch level I trauma center

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    Background: An emergency department thoracotomy (EDT) or an emergency thoracotomy (ET) in the operating theater are both beneficial in selected patients following thoracic penetrating injuries. Since outcome-descriptive European studies are lacking, the aim of this retrospective study was to evaluate ten years of experience at a Dutch level I trauma center. Method: Data on patients who underwent an immediate thoracotomy after sustaining a penetrating thoracic injury between October 2000 and January 2011 were collected from the trauma registry and hospital files. Descriptive and univariate analyses were performed. Results: Among 56 patients, 12 underwent an EDT and 44 an ET. Forty-six patients sustained one or multiple stab wounds, versus ten with one or multiple gunshot wounds. Patients who had undergone an EDT had a lower GCS (p < 0. 001), lower pre-hospital RTS and hospital triage RTS (p < 0. 001 and p = 0. 009, respectively), and a lower SBP (p = 0. 038). A witnessed loss of signs of life generally occurred in EDT patients and was accompanied by 100 % mortality. Survival following EDT was 25 %, which was significantly lower than in the ET group (75 %; p = 0. 002). Survivors had lower ISS (p = 0. 011), lower rates of pre-hospital (p = 0. 031) and hospital (p = 0. 003) hemodynamic instability, and a lower prevalence of concomitant abdominal injury (p = 0. 002). Conclusion: The overall survival rate in our study was 64 %. The outcome of immediate thoracotomy performed in this level I trauma center was similar to those obtained in high-incidence regions like the US and South Africa. This suggests that trauma units where immediate thoracotomies are not part of the daily routine can achieve similar results, if properly trained

    Faced with inequality: chicken do not have a general dosage compensation of sex-linked genes

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    <p>Abstract</p> <p>Background</p> <p>The contrasting dose of sex chromosomes in males and females potentially introduces a large-scale imbalance in levels of gene expression between sexes, and between sex chromosomes and autosomes. In many organisms, dosage compensation has thus evolved to equalize sex-linked gene expression in males and females. In mammals this is achieved by X chromosome inactivation and in flies and worms by up- or down-regulation of X-linked expression, respectively. While otherwise widespread in systems with heteromorphic sex chromosomes, the case of dosage compensation in birds (males ZZ, females ZW) remains an unsolved enigma.</p> <p>Results</p> <p>Here, we use a microarray approach to show that male chicken embryos generally express higher levels of Z-linked genes than female birds, both in soma and in gonads. The distribution of male-to-female fold-change values for Z chromosome genes is wide and has a mean of 1.4–1.6, which is consistent with absence of dosage compensation and sex-specific feedback regulation of gene expression at individual loci. Intriguingly, without global dosage compensation, the female chicken has significantly lower expression levels of Z-linked compared to autosomal genes, which is not the case in male birds.</p> <p>Conclusion</p> <p>The pronounced sex difference in gene expression is likely to contribute to sexual dimorphism among birds, and potentially has implication to avian sex determination. Importantly, this report, together with a recent study of sex-biased expression in somatic tissue of chicken, demonstrates the first example of an organism with a lack of global dosage compensation, providing an unexpected case of a viable system with large-scale imbalance in gene expression between sexes.</p

    Signatures of Environmental Genetic Adaptation Pinpoint Pathogens as the Main Selective Pressure through Human Evolution

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    Previous genome-wide scans of positive natural selection in humans have identified a number of non-neutrally evolving genes that play important roles in skin pigmentation, metabolism, or immune function. Recent studies have also shown that a genome-wide pattern of local adaptation can be detected by identifying correlations between patterns of allele frequencies and environmental variables. Despite these observations, the degree to which natural selection is primarily driven by adaptation to local environments, and the role of pathogens or other ecological factors as selective agents, is still under debate. To address this issue, we correlated the spatial allele frequency distribution of a large sample of SNPs from 55 distinct human populations to a set of environmental factors that describe local geographical features such as climate, diet regimes, and pathogen loads. In concordance with previous studies, we detected a significant enrichment of genic SNPs, and particularly non-synonymous SNPs associated with local adaptation. Furthermore, we show that the diversity of the local pathogenic environment is the predominant driver of local adaptation, and that climate, at least as measured here, only plays a relatively minor role. While background demography by far makes the strongest contribution in explaining the genetic variance among populations, we detected about 100 genes which show an unexpectedly strong correlation between allele frequencies and pathogenic environment, after correcting for demography. Conversely, for diet regimes and climatic conditions, no genes show a similar correlation between the environmental factor and allele frequencies. This result is validated using low-coverage sequencing data for multiple populations. Among the loci targeted by pathogen-driven selection, we found an enrichment of genes associated to autoimmune diseases, such as celiac disease, type 1 diabetes, and multiples sclerosis, which lends credence to the hypothesis that some susceptibility alleles for autoimmune diseases may be maintained in human population due to past selective processes

    Mobile multicast source support in PMIPv6 networks

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    With the widespread use of multimedia contents via mobile nodes (MNs), IP mobile multicast becomes more important for wireless, mobile, and ubiquitous multimedia applications. Until now, many research efforts have been made to provide IP multicast for the MNs. However, the existing mobile multicast schemes mostly focus on the mobility of receivers based on the host-based mobility solution that requires the MN to participate in the mobility management. Recent work has shown that service connectivity for mobile multicast sources is still a problem and attracts very little concern. With the development of the network-based mobility support protocol, mobile multicast source support schemes in Proxy Mobile IPv6 (PMIPv6) networks are needed urgently. In this paper, we propose a base solution (BS) and also a direct multicast routing scheme (DMRS) for mobile multicast source support in PMIPv6 networks. In the BS, the multicast listener discover (MLD) proxy function is adopted to transmit multicast data through the PMIPv6 tunnel. The DMRS can provide locally optimized traffic flows and avoid inefficient routing present in the BS. We evaluate and compare the performance of the proposed schemes with the Mobile IP bidirectional tunneling (MIP-BT) and Mobile IP remote subscription (MIP-RS) schemes by theoretical analysis and also implement the proposed schemes on the test-bed. The numerical results show that the BS and DMRS outperform the MIP-BT and MIP-RS in terms of signaling cost. Meanwhile, the experimental results verify the feasibility and validity of our proposed schemes. Furthermore, we study the optimal PMIPv6 domain size to reduce the total signaling cost for the proposed schemes
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