Assay strategies for the discovery and validation of therapeutics targeting <i>Brugia pahangi</i> Hsp90

The chemotherapy of lymphatic filariasis relies upon drugs such as diethylcarbamazine and ivermectin that largely target the microfilarial stages of the parasite, necessitating continued treatment over the long reproductive life span of the adult worm. The identification of compounds that target adult worms has been a long-term goal of WHO. Here we describe a fluorescence polarization assay for the identification of compounds that target Hsp90 in adult filarial worms. The assay was originally developed to identify inhibitors of Hsp90 in tumor cells, and relies upon the ability of small molecules to inhibit the binding of fluorescently labelled geldanamycin to Hsp90. We demonstrate that the assay works well with soluble extracts of Brugia, while extracts of the free-living nematode C. elegans fail to bind the probe, in agreement with data from other experiments. The assay was validated using known inhibitors of Hsp90 that compete with geldanamycin for binding to Hsp90, including members of the synthetic purine-scaffold series of compounds. The efficacy of some of these compounds against adult worms was confirmed in vitro. Moreover, the assay is sufficiently sensitive to differentiate between binding of purine-scaffold compounds to human and Brugia Hsp90. The assay is suitable for high-throughput screening and provides the first example of a format with the potential to identify novel inhibitors of Hsp90 in filarial worms and in other parasitic species where Hsp90 may be a target

Modulating gradients in regulatory signals within mesenchymal stem cell seeded hydrogels: a novel strategy to engineer zonal articular cartilage.

This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Engineering organs and tissues with the spatial composition and organisation of their native equivalents remains a major challenge. One approach to engineer such spatial complexity is to recapitulate the gradients in regulatory signals that during development and maturation are believed to drive spatial changes in stem cell differentiation. Mesenchymal stem cell (MSC) differentiation is known to be influenced by both soluble factors and mechanical cues present in the local microenvironment. The objective of this study was to engineer a cartilaginous tissue with a native zonal composition by modulating both the oxygen tension and mechanical environment thorough the depth of MSC seeded hydrogels. To this end, constructs were radially confined to half their thickness and subjected to dynamic compression (DC). Confinement reduced oxygen levels in the bottom of the construct and with the application of DC, increased strains across the top of the construct. These spatial changes correlated with increased glycosaminoglycan accumulation in the bottom of constructs, increased collagen accumulation in the top of constructs, and a suppression of hypertrophy and calcification throughout the construct. Matrix accumulation increased for higher hydrogel cell seeding densities; with DC further enhancing both glycosaminoglycan accumulation and construct stiffness. The combination of spatial confinement and DC was also found to increase proteoglycan-4 (lubricin) deposition toward the top surface of these tissues. In conclusion, by modulating the environment through the depth of developing constructs, it is possible to suppress MSC endochondral progression and to engineer tissues with zonal gradients mimicking certain aspects of articular cartilage.Funding was provided by Science Foundation Ireland (President of Ireland Young Researcher Award: 08/Y15/B1336) and the European Research Council (StemRepair – Project number 258463)

Kidney organ donation: developing family practice initiatives to reverse inertia

<p>Abstract</p> <p>Background</p> <p>Kidney transplantation is associated with greater long term survival rates and improved quality of life compared with dialysis. Continuous growth in the number of patients with kidney failure has not been matched by an increase in the availability of kidneys for transplantation. This leads to long waiting lists, higher treatment costs and negative health outcomes.</p> <p>Discussion</p> <p>Misunderstandings, public uncertainty and issues of trust in the medical system, that limit willingness to be registered as a potential donor, could be addressed by community dissemination of information and new family practice initiatives that respond to individuals' personal beliefs and concerns regarding organ donation and transplantation.</p> <p>Summary</p> <p>Tackling both personal and public inertia on organ donation is important for any community oriented kidney donation campaign.</p

The impact of donor policies in Europe: a steady increase, but not everywhere

<p>Abstract</p> <p>Background</p> <p>Transplantable organs are scarce everywhere. Therefore, countries have developed policies to support the efficient use of potential donors. Nevertheless, the shortage of organs remains. Were these policies in vain? The aim of this study is to assess the impact of donor policies on donor procurement in 10 Western European countries from 1995 to 2005.</p> <p>Method</p> <p>To assess the impact of the donor policies we studied the conversion of potential donors into effectuated donors. 80% of the donors died from CVAs or a (traffic) accident. We considered these mortality rates to be a good proxy for potential donors. Here we call the conversion of potential donors into actual donors 'the donor efficiency rate by proxy'.</p> <p>Results</p> <p>The mortality rates for CVA and (traffic) accidents have decreased in the countries under study. At the same time, in most countries the donor efficiency rates have steadily increased. The variance in donor efficiency rates between countries has also increased from 1995 to 2005. Four countries introduced a new consent system or changed their existing system, without (visible) long-term effects.</p> <p>Conclusion</p> <p>The overall increase in donor efficiency means that the efforts to improve donor policies have paid off. However, substantial differences between countries were found. The success of donor policies in terms of the number of absolute donors is blurred by the success of policies on traffic safety and CVA treatment. It remains unclear which specific policy measures are responsible for the increase in donor efficiency rates. This increase is not related to having a presumed consent system. Furthermore, an analysis of countries that introduced a new consent system or changed their system showed no effect on donor efficiency.</p

Factors associated with quality of life in systemic sclerosis: a cross-sectional study

© 2019, The Author(s). Introduction: Systemic sclerosis (SSc) is a connective tissue disease characterized by progressive fibrosis of the skin and internal organs, leading to their failure and disturbances in the morphology and function of blood vessels. The disease affects people in different ways, and identifying how the difficulties and limitations are related to quality of life may contribute to designing helpful interventions. The aim of this study was to identify factors associated with quality of life in people with SSc. Methods: This was a cross-sectional study conducted in 11 rheumatic centres in Poland. Patients diagnosed with SSc were included. Quality of life was measured using the SSc Quality of Life Questionnaire (SScQoL). The following candidate factors were entered in preliminary multivariable analysis: age, place of residence, marital status, occupational status, disease type, disease duration, pain, fatigue, intestinal problems, breathing problems, Raynaud’s symptoms, finger ulcerations, disease severity, functional disability, anxiety and depression. Factors that achieved statistical significance at the 10% level were then entered into a final multivariable model. Factors achieving statistical significance at the 5% level in the final model were considered to be associated with quality of life in SSc. Results: In total, 231 participants were included. Mean age (SD) was 55.82 (12.55) years, disease duration 8.39 (8.18) years and 198 (85.7%) were women. Factors associated with quality of life in SSc were functional disability (β = 2.854, p < 0.001) and anxiety (β = 0.404, p < 0.001). This model with two factors (functional disability and anxiety) explained 56.7% of the variance in patients with diffuse SSc and 73.2% in those with localized SSc. Conclusions: Functional disability and anxiety are significantly associated with quality of life in SSc. Interventions aimed at improving either of these factors may contribute towards improving the quality of life of people with SSc

Emerging issues and current trends in assistive technology use 2007-1010: practising, assisting and enabling learning for all

Following an earlier review in 2007, a further review of the academic literature relating to the uses of assistive technology (AT) by children and young people was completed, covering the period 2007-2011. As in the earlier review, a tripartite taxonomy: technology uses to train or practise, technology uses to assist learning and technology uses to enable learning, was used in order to structure the findings. The key markers for research in this field and during these three years were user involvement, AT on mobile mainstream devices, the visibility of AT, technology for interaction and collaboration, new and developing interfaces and inclusive design principles. The paper concludes by locating these developments within the broader framework of the Digital Divide

Host Genetics and HIV-1: The Final Phase?

This is a crucial transition time for human genetics in general, and for HIV host genetics in particular. After years of equivocal results from candidate gene analyses, several genome-wide association studies have been published that looked at plasma viral load or disease progression. Results from other studies that used various large-scale approaches (siRNA screens, transcriptome or proteome analysis, comparative genomics) have also shed new light on retroviral pathogenesis. However, most of the inter-individual variability in response to HIV-1 infection remains to be explained: genome resequencing and systems biology approaches are now required to progress toward a better understanding of the complex interactions between HIV-1 and its human host

Quasispecies Theory and the Behavior of RNA Viruses

A large number of medically important viruses, including HIV, hepatitis C virus, and influenza, have RNA genomes. These viruses replicate with extremely high mutation rates and exhibit significant genetic diversity. This diversity allows a viral population to rapidly adapt to dynamic environments and evolve resistance to vaccines and antiviral drugs. For the last 30 years, quasispecies theory has provided a population-based framework for understanding RNA viral evolution. A quasispecies is a cloud of diverse variants that are genetically linked through mutation, interact cooperatively on a functional level, and collectively contribute to the characteristics of the population. Many predictions of quasispecies theory run counter to traditional views of microbial behavior and evolution and have profound implications for our understanding of viral disease. Here, we discuss basic principles of quasispecies theory and describe its relevance for our understanding of viral fitness, virulence, and antiviral therapeutic strategy

Host hindrance to HIV-1 replication in monocytes and macrophages

Monocytes and macrophages are targets of HIV-1 infection and play critical roles in multiple aspects of viral pathogenesis. HIV-1 can replicate in blood monocytes, although only a minor proportion of circulating monocytes harbor viral DNA. Resident macrophages in tissues can be infected and function as viral reservoirs. However, their susceptibility to infection, and their capacity to actively replicate the virus, varies greatly depending on the tissue localization and cytokine environment. The susceptibility of monocytes to HIV-1 infection in vitro depends on their differentiation status. Monocytes are refractory to infection and become permissive upon differentiation into macrophages. In addition, the capacity of monocyte-derived macrophages to sustain viral replication varies between individuals. Host determinants regulate HIV-1 replication in monocytes and macrophages, limiting several steps of the viral life-cycle, from viral entry to virus release. Some host factors responsible for HIV-1 restriction are shared with T lymphocytes, but several anti-viral mechanisms are specific to either monocytes or macrophages. Whilst a number of these mechanisms have been identified in monocytes or in monocyte-derived macrophages in vitro, some of them have also been implicated in the regulation of HIV-1 infection in vivo, in particular in the brain and the lung where macrophages are the main cell type infected by HIV-1. This review focuses on cellular factors that have been reported to interfere with HIV-1 infection in monocytes and macrophages, and examines the evidences supporting their role in vivo, highlighting unique aspects of HIV-1 restriction in these two cell types