2,737 research outputs found

    Co-exposure of C60 fullerene with benzo[a]pyrene results in enhanced biological effects in cells as determined by Fourier-transform infrared spectroscopy

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    C60 fullerene (C60) is a promising manufactured carbon-based nanoparticles (NPs). With an increasing number of applications, it is being found in the environment. In addition, C60 is likely to associate with other environmental toxic contaminants. How such interactions with C60 can impact on the environmental fate, transport and bioavailability of toxicants remains unknown. Benzo[a]pyrene (B[a]P) is a polycyclic aromatic hydrocarbon (PAH). Herein, two cell lines (fish gill or MCF-7 cells) were employed to explore the biological impacts of co-exposure to C60 and B[a]P. Post-exposure cells were interrogated using Fourier-transformation infrared (FTIR) microspectroscopy. By inputting spectral data into principal component analysis and linear discriminant analysis, data reduction allowed for visualisation of cell categorization and identification of wavenumber-related biomarkers corresponding to cellular alterations. Our results indicate that low-dose C60 increases B[a]P-induced alterations, while C60 at high concentrations reduces these effects. We also found that although C60 co-exposure increases B[a]P-induced CYP1A1 induction, co-exposure seemingly attenuates the levels of oxidative damage induced by either agent singly. This suggests that interactions between environmental NPs and contaminants are complex and unpredictable

    Learning Optimal Deep Projection of 18^{18}F-FDG PET Imaging for Early Differential Diagnosis of Parkinsonian Syndromes

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    Several diseases of parkinsonian syndromes present similar symptoms at early stage and no objective widely used diagnostic methods have been approved until now. Positron emission tomography (PET) with 18^{18}F-FDG was shown to be able to assess early neuronal dysfunction of synucleinopathies and tauopathies. Tensor factorization (TF) based approaches have been applied to identify characteristic metabolic patterns for differential diagnosis. However, these conventional dimension-reduction strategies assume linear or multi-linear relationships inside data, and are therefore insufficient to distinguish nonlinear metabolic differences between various parkinsonian syndromes. In this paper, we propose a Deep Projection Neural Network (DPNN) to identify characteristic metabolic pattern for early differential diagnosis of parkinsonian syndromes. We draw our inspiration from the existing TF methods. The network consists of a (i) compression part: which uses a deep network to learn optimal 2D projections of 3D scans, and a (ii) classification part: which maps the 2D projections to labels. The compression part can be pre-trained using surplus unlabelled datasets. Also, as the classification part operates on these 2D projections, it can be trained end-to-end effectively with limited labelled data, in contrast to 3D approaches. We show that DPNN is more effective in comparison to existing state-of-the-art and plausible baselines.Comment: 8 pages, 3 figures, conference, MICCAI DLMIA, 201

    Example-Guided Style-Consistent Image Synthesis from Semantic Labeling

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    HIV prevalence and undiagnosed infection among a community sample of gay and bisexual men in Scotland, 2005-2011: implications for HIV testing policy and prevention

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    <b>Objective</b><p></p> To examine HIV prevalence, HIV testing behaviour, undiagnosed infection and risk factors for HIV positivity among a community sample of gay men in Scotland.<p></p> <b>Methods</b><p></p> Cross-sectional survey of gay and bisexual men attending commercial gay venues in Glasgow and Edinburgh, Scotland with voluntary anonymous HIV testing of oral fluid samples in 2011. A response rate of 65.2% was achieved (1515 participants).<p></p> <b>Results</b><p></p> HIV prevalence (4.8%, 95% confidence interval, CI 3.8% to 6.2%) remained stable compared to previous survey years (2005 and 2008) and the proportion of undiagnosed infection among HIV-positive men (25.4%) remained similar to that recorded in 2008. Half of the participants who provided an oral fluid sample stated that they had had an HIV test in the previous 12 months; this proportion is significantly higher when compared to previous study years (50.7% versus 33.8% in 2005, p<0.001). Older age (>25 years) was associated with HIV positivity (1.8% in those <25 versus 6.4% in older ages group) as was a sexually transmitted infection (STI) diagnosis within the previous 12 months (adjusted odds ratio 2.13, 95% CI 1.09–4.14). There was no significant association between age and having an STI or age and any of the sexual behaviours recorded.<p></p> <b>Conclusion</b><p></p> HIV transmission continues to occur among gay and bisexual men in Scotland. Despite evidence of recent testing within the previous six months, suggesting a willingness to test, the current opt-out policy may have reached its limit with regards to maximising HIV test uptake. Novel strategies are required to improve regular testing opportunities and more frequent testing as there are implications for the use of other biomedical HIV interventions.<p></p&gt

    Pathological Crying and Laughing in Motor Neuron Disease: Pathobiology, Screening, Intervention

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    Pathological crying and laughing (PCL) has significant quality-of-life implications in amyotrophic lateral sclerosis (ALS); it can provoke restrictive life-style modifications and lead to social isolation. Despite its high prevalence and quality of life implications, it remains surprisingly understudied. Divergent pathophysiological models have been proposed, centered on corticobulbar tract degeneration, prefrontal cortex pathology, sensory deafferentation, and impaired cerebellar gate-control mechanisms. Quantitative MRI techniques and symptom-specific clinical instruments offer unprecedented opportunities to elucidate the anatomical underpinnings of PCL pathogenesis. Emerging neuroimaging studies of ALS support the role of cortico–pontine–cerebellar network dysfunction in context-inappropriate emotional responses. The characterization of PCL-associated pathophysiological processes is indispensable for the development of effective pharmacological therapies

    Safety and efficacy of fluticasone propionate in the topical treatment of skin diseases

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    Fluticasone propionate - the first carbothioate corticosteroid - has been classified as a potent anti-inflammatory drug for dermatological use. It is available as 0.05% cream and 0.005% ointment formulations for the acute and maintenance treatment of patients with dermatological disorders such as atopic dermatitis, psoriasis and vitiligo. This glucocorticoid is characterized by high lipophilicity, high glucocorticoid receptor binding and activation, and a rapid metabolic turnover in skin. Although skin blanching following fluticasone propionate exceeds that of corticosteroids of medium strength, several clinical trials demonstrate a low potential for cutaneous and systemic side-effects, even in difficult-to-treat areas like the face, the eyelids and intertriginous areas. Even among paediatric patients with atopic dermatitis, fluticasone propionate proved to be safe and effective. These pharmacological and clinical properties are reflected by the high therapeutic index of this glucocorticoid

    Tracking a Fast-Moving Disease: Longitudinal Markers, Monitoring, and Clinical Trial Endpoints in ALS

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    Amyotrophic lateral sclerosis (ALS) encompasses a heterogeneous group of phenotypes with different progression rates, varying degree of extra-motor involvement and divergent progression patterns. The natural history of ALS is increasingly evaluated by large, multi-time point longitudinal studies, many of which now incorporate presymptomatic and post-mortem assessments. These studies not only have the potential to characterize patterns of anatomical propagation, molecular mechanisms of disease spread, but also to identify pragmatic monitoring markers. Sensitive markers of progressive neurodegenerative change are indispensable for clinical trials and individualized patient care. Biofluid markers, neuroimaging indices, electrophysiological markers, rating scales, questionnaires, and other disease-specific instruments have divergent sensitivity profiles. The discussion of candidate monitoring markers in ALS has a dual academic and clinical relevance, and is particularly timely given the increasing number of pharmacological trials. The objective of this paper is to provide a comprehensive and critical review of longitudinal studies in ALS, focusing on the sensitivity profile of established and emerging monitoring markers

    人乳头瘤病毒衣壳蛋白C末端结构臂具有免疫原性并参与病毒—宿主细胞的相互作用

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    文章简介宫颈癌是全球女性第二大常见恶性肿瘤,人乳头瘤病毒(HPV)是导致女性宫颈癌发生的主要原因。HPV型别众多,主要的高危型型别种类多达15种,且型别间免疫血清交叉保护能力极低,目前国际上已上市的预防性多价HPV疫苗均不能为接种者提供完全保护。长期以来,高分辨率HPV的病毒结构信息的缺乏限制了对HPV病毒的组装模式和感染机制的深入理解,进国家自然科学基金;美国国立卫生院(NIH)基金的资助

    Deep generative modeling for single-cell transcriptomics.

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    Single-cell transcriptome measurements can reveal unexplored biological diversity, but they suffer from technical noise and bias that must be modeled to account for the resulting uncertainty in downstream analyses. Here we introduce single-cell variational inference (scVI), a ready-to-use scalable framework for the probabilistic representation and analysis of gene expression in single cells ( https://github.com/YosefLab/scVI ). scVI uses stochastic optimization and deep neural networks to aggregate information across similar cells and genes and to approximate the distributions that underlie observed expression values, while accounting for batch effects and limited sensitivity. We used scVI for a range of fundamental analysis tasks including batch correction, visualization, clustering, and differential expression, and achieved high accuracy for each task

    DNA end resection by Dna2–Sgs1–RPA and its stimulation by Top3–Rmi1 and Mre11–Rad50–Xrs2

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    The repair of DNA double-strand breaks (DSBs) by homologous recombination requires processing of broken ends. For repair to start, the DSB must first be resected to generate a 3′-single-stranded DNA (ssDNA) overhang, which becomes a substrate for the DNA strand exchange protein, Rad51 (ref. 1). Genetic studies have implicated a multitude of proteins in the process, including helicases, nucleases and topoisomerases. Here we biochemically reconstitute elements of the resection process and reveal that it requires the nuclease Dna2, the RecQ-family helicase Sgs1 and the ssDNA-binding protein replication protein-A (RPA). We establish that Dna2, Sgs1 and RPA constitute a minimal protein complex capable of DNA resection in vitro. Sgs1 helicase unwinds the DNA to produce an intermediate that is digested by Dna2, and RPA stimulates DNA unwinding by Sgs1 in a species-specific manner. Interestingly, RPA is also required both to direct Dna2 nucleolytic activity to the 5′-terminated strand of the DNA break and to inhibit 3′ to 5′ degradation by Dna2, actions that generate and protect the 3′-ssDNA overhang, respectively. In addition to this core machinery, we establish that both the topoisomerase 3 (Top3) and Rmi1 complex and the Mre11–Rad50–Xrs2 complex (MRX) have important roles as stimulatory components. Stimulation of end resection by the Top3–Rmi1 heterodimer and the MRX proteins is by complex formation with Sgs1 (refs 5, 6), which unexpectedly stimulates DNA unwinding. We suggest that Top3–Rmi1 and MRX are important for recruitment of the Sgs1–Dna2 complex to DSBs. Our experiments provide a mechanistic framework for understanding the initial steps of recombinational DNA repair in eukaryotes
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