1,426 research outputs found

    In vitro selection of miltefosine resistance in promastigotes of Leishmania donovani from Nepal: genomic and metabolomic characterization.

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    In this study, we followed the genomic, lipidomic and metabolomic changes associated with the selection of miltefosine (MIL) resistance in two clinically derived Leishmania donovani strains with different inherent resistance to antimonial drugs (antimony sensitive strain Sb-S; and antimony resistant Sb-R). MIL-R was easily induced in both strains using the promastigote-stage, but a significant increase in MIL-R in the intracellular amastigote compared to the corresponding wild-type did not occur until promastigotes had adapted to 12.2 ÎźM MIL. A variety of common and strain-specific genetic changes were discovered in MIL-adapted parasites, including deletions at the LdMT transporter gene, single-base mutations and changes in somy. The most obvious lipid changes in MIL-R promastigotes occurred to phosphatidylcholines and lysophosphatidylcholines and results indicate that the Kennedy pathway is involved in MIL resistance. The inherent Sb resistance of the parasite had an impact on the changes that occurred in MIL-R parasites, with more genetic changes occurring in Sb-R compared with Sb-S parasites. Initial interpretation of the changes identified in this study does not support synergies with Sb-R in the mechanisms of MIL resistance, though this requires an enhanced understanding of the parasite's biochemical pathways and how they are genetically regulated to be verified fully.This study was supported by as part of the FP7 EC K aladrug-R project (http://cordis.europa.eu/project/rcn/88823_en.html, grant number: 222895). JAC and MJS are supported by the Wellcome Trust via their core support for the Wellcome Trust Sanger Institute (grant number 098051) . TMF was funded by a BBSRC Research Experience Placement (grant number BB/J014540/1). CJRI was supported by a Sir Henry Dale Fellowship jointly funded by the Wellcome Trust and the Royal Society (grant number 101239/Z/13/Z). This research was supported in part by the National Science Foundation (grant number: NSF PHY11-25915) and by the Belgian Science Policy Office (TRIT, contract P7/41, to J-C.D.).This is the final version of the article. It was first available from Wiley via http://dx.doi.org/10.1111/mmi.1329

    Volumizing effects of a smooth, highly cohesive, viscous 20-mg/mL hyaluronic acid volumizing filler: prospective European study

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    <p>Abstract</p> <p>Background</p> <p>Facial volume loss contributes significantly to facial aging. The 20-mg/mL hyaluronic acid (HA) formulation used in this study is a smooth, highly cohesive, viscous, fully reversible, volumizing filler indicated to restore facial volume. This first prospective study evaluated use in current aesthetic clinical practice.</p> <p>Methods</p> <p>A pan-European evaluation conducted under guidelines of the World Association of Opinion and Marketing Research, the trial comprised a baseline visit (visit 1) and a follow-up (visit 2) at 14 Âą 7 days posttreatment. Physicians photographed patients at each visit. Each patient was treated with the 20-mg/mL HA volumizing filler as supplied in standard packaging. Procedural details, aesthetic outcomes, safety, and physician and patient ratings of their experience were recorded.</p> <p>Results</p> <p>Fifteen physicians and 70 patients (91% female; mean age: 50 years) participated. Mean volume loss at baseline was 3.7 (moderate) on the Facial Volume Loss Scale. Local anesthesia was used in 64.3% of cases. Most injections (85%) were administered with needles rather than cannulas. Of the 208 injections, 59% were in the malar region, primarily above the periosteum. Subcutaneous injections were most common for other sites. The mean total injection volume per patient was 4.6 mL. The mean volume loss score declined significantly (<it>P </it>< .001) to 2.1 at visit 2. On the Global Aesthetic Improvement Scale, 88% and 76% of the treatments were rated very much improved or much improved by physicians and patients, respectively. Of the physicians, 95.6% rated this HA filler as very or fairly easy to use. Similarly, 92% of patients were very likely or quite likely to return for treatment; nearly all (98%) would recommend this treatment to friends. Transient (mean duration: 5.5 days) injection-site adverse events (AEs) occurred in 24 patients. Bruising was the most common AE.</p> <p>Conclusion</p> <p>The 20-mg/mL smooth, highly cohesive, viscous, volumizing HA filler was effective, well tolerated, and easy to use in current clinical practice. Participants were very likely to recommend this product to colleagues and friends, and patients would be very or quite likely to request this product for future treatments.</p

    Helical Chirality: a Link between Local Interactions and Global Topology in DNA

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    DNA supercoiling plays a major role in many cellular functions. The global DNA conformation is however intimately linked to local DNA-DNA interactions influencing both the physical properties and the biological functions of the supercoiled molecule. Juxtaposition of DNA double helices in ubiquitous crossover arrangements participates in multiple functions such as recombination, gene regulation and DNA packaging. However, little is currently known about how the structure and stability of direct DNA-DNA interactions influence the topological state of DNA. Here, a crystallographic analysis shows that due to the intrinsic helical chirality of DNA, crossovers of opposite handedness exhibit markedly different geometries. While right-handed crossovers are self-fitted by sequence-specific groove-backbone interaction and bridging Mg2+ sites, left-handed crossovers are juxtaposed by groove-groove interaction. Our previous calculations have shown that the different geometries result in differential stabilisation in solution, in the presence of divalent cations. The present study reveals that the various topological states of the cell are associated with different inter-segmental interactions. While the unstable left-handed crossovers are exclusively formed in negatively supercoiled DNA, stable right-handed crossovers constitute the local signature of an unusual topological state in the cell, such as the positively supercoiled or relaxed DNA. These findings not only provide a simple mechanism for locally sensing the DNA topology but also lead to the prediction that, due to their different tertiary intra-molecular interactions, supercoiled molecules of opposite signs must display markedly different physical properties. Sticky inter-segmental interactions in positively supercoiled or relaxed DNA are expected to greatly slow down the slithering dynamics of DNA. We therefore suggest that the intrinsic helical chirality of DNA may have oriented the early evolutionary choices for DNA topology

    Lessons to be learnt from Leishmania studies

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    Leishmaniasis is a disease caused by infection with the protozoan parasite Leishmania, which is responsible for three main types of disease: cutaneous leishmaniasis, visceral leishmaniasis and mucocutaneous leishmaniasis based to the site of infection for the particular species. This presents a major challenge to successful drug treatment, as a drug must not only reach antileishmanial concentrations in infected macrophages, the parasites' host cell, but also reach infected cells in locations specific to the type of disease. In this paper we discuss how studies using Leishmania have contributed to our knowledge on how drug delivery systems can be used to improve drug efficacy and delivery

    Imaging of Oxidation-Specific Epitopes in Atherosclerosis and Macrophage-Rich Vulnerable Plaques

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    Oxidative stress, and in particular oxidation of lipoproteins, is a hallmark of atherosclerosis. Upon entry of lipoproteins into the vessel wall, a cascade of pro-atherogenic pathways is initiated whereby the reaction of reactive oxygen species with substrates amenable to oxidation, such as polyunsaturated fatty acids, generates a variety of oxidation-specific epitopes on lipoproteins, proteins in the vessel wall, and apoptotic macrophages. Several of these oxidation-specific epitopes have been well characterized and specific murine and fully human antibodies have been generated in our laboratory to detect them in the vessel wall. We have developed radionuclide, gadolinium and iron oxide based MRI techniques to noninvasively image oxidation-specific epitopes in atherosclerotic lesions. These approaches quantitate plaque burden and also allow detection of atherosclerosis regression and plaque stabilization. In particular, gadolinium micelles or lipid-coated ultrasmall superparamagnetic iron oxide particles containing oxidation-specific antibodies accumulate within macrophages in the artery wall, suggesting they may image the most unstable plaques. Translation of these approaches to humans may allow a sensitive technique to image and monitor high-risk atherosclerotic lesions and may guide optimal therapeutic interventions

    Improving the implementation of health workforce policies through governance: a review of case studies

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    <p>Abstract</p> <p>Introduction</p> <p>Responsible governance is crucial to national development and a catalyst for achieving the Millennium Development Goals. To date, governance seems to have been a neglected issue in the field of human resources for health (HRH), which could be an important reason why HRH policy formulation and implementation is often poor. This article aims to describe how governance issues have influenced HRH policy development and to identify governance strategies that have been used, successfully or not, to improve HRH policy implementation in low- and middle-income countries (LMIC).</p> <p>Methods</p> <p>We performed a descriptive literature review of HRH case studies which describe or evaluate a governance-related intervention at country or district level in LMIC. In order to systematically address the term 'governance' a framework was developed and governance aspects were regrouped into four dimensions: 'performance', 'equity and equality', 'partnership and participation' and 'oversight'.</p> <p>Results and discussion</p> <p>In total 16 case studies were included in the review and most of the selected studies covered several governance dimensions. The dimension 'performance' covered several elements at the core of governance of HRH, decentralization being particularly prominent. Although improved equity and/or equality was, in a number of interventions, a goal, inclusiveness in policy development and fairness and transparency in policy implementation did often not seem adequate to guarantee the corresponding desirable health workforce scenario. Forms of partnership and participation described in the case studies are numerous and offer different lessons. Strikingly, in none of the articles was 'partnerships' a core focus. A common theme in the dimension of 'oversight' is local-level corruption, affecting, amongst other things, accountability and local-level trust in governance, and its cultural guises. Experiences with accountability mechanisms for HRH policy development and implementation were lacking.</p> <p>Conclusion</p> <p>This review shows that the term 'governance' is neither prominent nor frequent in recent HRH literature. It provides initial lessons regarding the influence of governance on HRH policy development and implementation. The review also shows that the evidence base needs to be improved in this field in order to better understand how governance influences HRH policy development and implementation. Tentative lessons are discussed, based on the case studies.</p

    Preventing mental health problems in children : the families in mind population-based cluster randomised controlled trial.

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    BackgroundExternalising and internalising problems affect one in seven school-aged children and are the single strongest predictor of mental health problems into early adolescence. As the burden of mental health problems persists globally, childhood prevention of mental health problems is paramount. Prevention can be offered to all children (universal) or to children at risk of developing mental health problems (targeted). The relative effectiveness and costs of a targeted only versus combined universal and targeted approach are unknown. This study aims to the effectiveness, costs and uptake of two approaches to early childhood prevention of mental health problems ie: a Combined universal-targeted approach, versus a Targeted only approach, in comparison to current primary care services (Usual care).DesignThree armed, population-level cluster randomised trial (2010-2014) within the universal, well child Maternal Child Health system, attended by more than 80% of families in Victoria, Australia at infant age eight months. Participants: Families of eight month old children from nine participating local government areas. Randomised to one of three groups: Combined, Targeted or Usual care. Intervention: (a) the Combined universal and targeted program where all families are offered the universal Toddlers Without Tears group parenting program followed by the targeted Family Check-Up one-on-one program or (b) the Targeted Family Check-Up program. The Family Check-Up program is only offered to children at risk of behavioural problems. Analysis: Participants will be analysed according to the trial arm to which they were randomised, using logistic and linear regression models to compare primary and secondary outcomes. An economic evaluation (cost consequences analysis) will compare incremental costs to all incremental outcomes from a societal perspective.DiscussionThis trial will inform public health policy by making recommendations about the effectiveness and cost-effectiveness of these early prevention programs. If effective prevention programs can be implemented at the population level, the growing burden of mental health problems could be curbed.<br /
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