10,920 research outputs found

    Invasive pulmonary aspergillosis post extracorporeal membrane oxygenation support and literature review

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    The use of extracorporeal membrane oxygenation (ECMO) for reversible pulmonary failure in critically ill patients has increased over the last few decades. Nosocomial infections are a major complication of ECMO and fungi have been found to be a common cause. Herein, we describe a case of invasive pulmonary aspergillosis following ECMO, which was successfully treated with combination antifungal therapy and interferon-gamma

    Advanced Fluorescence Microscopy Techniques-FRAP, FLIP, FLAP, FRET and FLIM

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    Fluorescence microscopy provides an efficient and unique approach to study fixed and living cells because of its versatility, specificity, and high sensitivity. Fluorescence microscopes can both detect the fluorescence emitted from labeled molecules in biological samples as images or photometric data from which intensities and emission spectra can be deduced. By exploiting the characteristics of fluorescence, various techniques have been developed that enable the visualization and analysis of complex dynamic events in cells, organelles, and sub-organelle components within the biological specimen. The techniques described here are fluorescence recovery after photobleaching (FRAP), the related fluorescence loss in photobleaching (FLIP), fluorescence localization after photobleaching (FLAP), Forster or fluorescence resonance energy transfer (FRET) and the different ways how to measure FRET, such as acceptor bleaching, sensitized emission, polarization anisotropy, and fluorescence lifetime imaging microscopy (FLIM). First, a brief introduction into the mechanisms underlying fluorescence as a physical phenomenon and fluorescence, confocal, and multiphoton microscopy is given. Subsequently, these advanced microscopy techniques are introduced in more detail, with a description of how these techniques are performed, what needs to be considered, and what practical advantages they can bring to cell biological research

    Complex patterns of local adaptation in teosinte

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    Populations of widely distributed species often encounter and adapt to specific environmental conditions. However, comprehensive characterization of the genetic basis of adaptation is demanding, requiring genome-wide genotype data, multiple sampled populations, and a good understanding of population structure. We have used environmental and high-density genotype data to describe the genetic basis of local adaptation in 21 populations of teosinte, the wild ancestor of maize. We found that altitude, dispersal events and admixture among subspecies formed a complex hierarchical genetic structure within teosinte. Patterns of linkage disequilibrium revealed four mega-base scale inversions that segregated among populations and had altitudinal clines. Based on patterns of differentiation and correlation with environmental variation, inversions and nongenic regions play an important role in local adaptation of teosinte. Further, we note that strongly differentiated individual populations can bias the identification of adaptive loci. The role of inversions in local adaptation has been predicted by theory and requires attention as genome-wide data become available for additional plant species. These results also suggest a potentially important role for noncoding variation, especially in large plant genomes in which the gene space represents a fraction of the entire genome

    The dependence of alpha-tocopheroxyl radical reduction by hydroxy-2,3-diarylxanthones on structure and micro-environment

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    The flavonoid quercetin is known to reduce the α-tocopheroxyl radical (˙TocO) and reconstitute α-tocopherol (TocOH). Structurally related polyphenolic compounds, hydroxy-2,3-diarylxanthones (XH), exhibit antioxidant activity which exceeds that of quercetin in biological systems. In the present study repair of ˙TocO by a series of these XH has been evaluated using pulse radiolysis. It has been shown that, among the studied XH, only 2,3-bis(3,4-dihydroxyphenyl)-9H-xanthen-9-one (XH9) reduces ˙TocO, though repair depends strongly on the micro-environment. In cationic cetyltrimethylammonium bromide (CTAB) micelles, 30% of ˙TocO radicals are repaired at a rate constant of ∼7.4 × 106 M−1 s−1 by XH9 compared to 1.7 × 107 M−1 s−1 by ascorbate. Water-soluble Trolox (TrOH) radicals (˙TrO) are restored by XH9 in CTAB (rate constant ∼3 × 104 M−1 s−1) but not in neutral TX100 micelles where only 15% of ˙TocO are repaired (rate constant ∼4.5 × 105 M−1 s−1). In basic aqueous solutions ˙TrO is readily reduced by deprotonated XH9 species leading to ionized XH9 radical species (radical pKa ∼10). An equilibrium is observed (K = 130) yielding an estimate of 130 mV for the reduction potential of the [˙X9,H+/XH9] couple at pH 11, lower than the 250 mV for the [˙TrO,H+/TrOH] couple. A comparable value (100 mV) has been determined by cyclic voltammetry measurements

    International Veterinary Epilepsy Task Force recommendations for a veterinary epilepsy-specific MRI protocol

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    Epilepsy is one of the most common chronic neurological diseases in veterinary practice. Magnetic resonance imaging (MRI) is regarded as an important diagnostic test to reach the diagnosis of idiopathic epilepsy. However, given that the diagnosis requires the exclusion of other differentials for seizures, the parameters for MRI examination should allow the detection of subtle lesions which may not be obvious with existing techniques. In addition, there are several differentials for idiopathic epilepsy in humans, for example some focal cortical dysplasias, which may only apparent with special sequences, imaging planes and/or particular techniques used in performing the MRI scan. As a result, there is a need to standardize MRI examination in veterinary patients with techniques that reliably diagnose subtle lesions, identify post-seizure changes, and which will allow for future identification of underlying causes of seizures not yet apparent in the veterinary literature. There is a need for a standardized veterinary epilepsy-specific MRI protocol which will facilitate more detailed examination of areas susceptible to generating and perpetuating seizures, is cost efficient, simple to perform and can be adapted for both low and high field scanners. Standardisation of imaging will improve clinical communication and uniformity of case definition between research studies. A 6–7 sequence epilepsy-specific MRI protocol for veterinary patients is proposed and further advanced MR and functional imaging is reviewed

    Population-Level Benefits from Providing Effective HIV Prevention Means to Pregnant Women in High Prevalence Settings

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    Background:HIV prevalence among pregnant women in Southern Africa is extremely high. Epidemiological studies suggest that pregnancy increases the risk of HIV sexual acquisition and that HIV infections acquired during pregnancy carry higher risk of mother-to-child transmission (MTCT). We analyze the potential benefits from extending the availability of effective microbicide to pregnant women (in addition to non-pregnant women) in a wide-scale intervention.Methods and Findings:A transmission dynamic model was designed to assess the impact of microbicide use in high HIV prevalence settings and to estimate proportions of new HIV infections, infections acquired during pregnancy, and MTCT prevented over 10 years. Our analysis suggests that consistent use of microbicide with 70% efficacy by 60% of non-pregnant women may prevent approximately 40% and 15% of new infections in women and men respectively over 10 years, assuming no additional increase in HIV risk to either partner during pregnancy (RRHIV/preg = 1). It may also prevent 8-15% MTCT depending on the increase in MTCT risk when HIV is acquired during pregnancy compared to before pregnancy (RRMTCT/preg). Extending the microbicides use during pregnancy may improve the effectiveness of the intervention by 10% (RRHIV/preg = 1) to 25% (RRHIV/preg = 2) and reduce the number of HIV infections acquired during pregnancy by 40% to 70% in different scenarios. It may add between 6% (RRHIV/preg = 1, RRMTCT/preg = 1) and 25% (RRHIV/preg = 2, RRMTCT/preg = 4) to the reduction in the residual MTCT.Conclusion:Providing safe and effective microbicide to pregnant women in the context of wide-scale interventions would be desirable as it would increase the effectiveness of the intervention and significantly reduce the number of HIV infections acquired during pregnancy. The projected benefits from covering pregnant women by the HIV prevention programs is more substantial in communities in which the sexual risk during pregnancy is elevated. © 2013 Dimitrov et al

    Developing a model of mental health self-care support for children and young people through an integrated evaluation of available types of provision involving systematic review, meta-analysis and case study

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    Background The mental health of children and young people (CYP) is a major UK public health concern. Recent policy reviews have identified that service provision for CYP with mental health needs is not as effective, responsive, accessible or child-centred as it could be. Following on from a previous National Institute for Health Research (NIHR) study into self-care support for CYP with long-term physical health needs, this study explored self-care support’s potential in CYP’s mental health. Objectives To identify and evaluate the types of mental health self-care support used by, and available to, CYP and their parents, and to establish how such support interfaces with statutory and non-statutory service provision. Design Two inter-related systematic literature reviews (an effectiveness review with meta-analysis and a perceptions review), together with a service mapping exercise and case study. Setting Global (systematic reviews); England and Wales (mapping exercise and case study). Participants (case study) Fifty-two individuals (17 CYP, 16 family members and 19 staff) were interviewed across six sites. Main outcome measures (meta-analysis) A measure of CYP’s mental health symptomatology. Data sources (literature reviews) MEDLINE, Cumulative Index to Nursing and Allied Health Literature (CINAHL), PsycINFO, All Evidence-Based Medicine (EBM) Reviews, Applied Social Sciences Index and Abstracts (ASSIA) and Education Resources Information Center (ERIC). Review methods Titles and abstracts of papers were screened for relevance then grouped into studies. Two independent reviewers extracted data from studies meeting the inclusion criteria. A descriptive analysis and meta-analysis were conducted for the effectiveness review; descriptive analyses were conducted for the perceptions review. These analyses were integrated to elicit a mixed-methods review. Results Sixty-five of 71 included studies were meta-analysable. These 65 studies elicited 71 comparisons which, when meta-analysed, suggested that self-care support interventions were effective at 6-month [standardised mean difference (SMD) = −0.20; 95% confidence interval (CI) −0.28 to −0.11] and 12-month (SMD = −0.12; 95% CI −0.17 to −0.06) follow-ups. However, judged against Cochrane criteria, the studies were mostly low quality. Key elements of self-care support identified in the perceptions review were the acquisition of knowledge and skills, peer support and the relationship with the self-care support agent; CYP also had different perceptions from adults about what is important in self-care support. The mapping exercise identified 27 providers of 33 self-care support services. According to the case study data, effective self-care support services are predicated on flexibility; straightforward access; non-judgemental, welcoming organisations and staff; the provision of time and attention; opportunities to learn and practise skills relevant to self-care; and systems of peer support. Conclusions Mental health self-care support interventions for CYP are modestly effective in the short to medium term. Self-care support can be conceptualised as a process which has overlap with ‘recovery’. CYP and their families want choice and flexibility in the provision of such interventions and a continued relationship with services after the nominal therapy period. Those delivering self-care support need to have specific child-centred attributes. Future work Future work should focus on under-represented conditions (e.g. psychosis, eating disorders, self-harm); the role of technology, leadership and readiness in self-care support; satisfaction in self-care support; the conceptualisation of self-care support in CYP’s mental health; and efficacy and cost-effectiveness
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