208 research outputs found

    Transient and sustained incentive effects on electrophysiological indices of cognitive control in younger and older adults

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    Preparing for upcoming events, separating task-relevant from task-irrelevant information and efficiently responding to stimuli all require cognitive control. The adaptive recruitment of cognitive control depends on activity in the dopaminergic reward system as well as the frontoparietal control network. In healthy aging, dopaminergic neuromodulation is reduced, resulting in altered incentive-based recruitment of control mechanisms. In the present study, younger adults (18–28 years) and healthy older adults (66–89 years) completed an incentivized flanker task that included gain, loss, and neutral trials. Event-related potentials (ERPs) were recorded at the time of incentive cue and target presentation. We examined the contingent negative variation (CNV), implicated in stimulus anticipation and response preparation, as well as the P3, which is involved in the evaluation of visual stimuli. Both younger and older adults showed transient incentive-based modulation of CNV. Critically, cue-locked and target-locked P3s were influenced by transient and sustained effects of incentives in younger adults, while such modulation was limited to a sustained effect of gain incentives on cue-P3 in older adults. Overall, these findings are in line with an age-related reduction in the flexible recruitment of preparatory and target-related cognitive control processes in the presence of motivational incentives

    Balancing repair and tolerance of DNA damage caused by alkylating agents

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    Alkylating agents constitute a major class of frontline chemotherapeutic drugs that inflict cytotoxic DNA damage as their main mode of action, in addition to collateral mutagenic damage. Numerous cellular pathways, including direct DNA damage reversal, base excision repair (BER) and mismatch repair (MMR), respond to alkylation damage to defend against alkylation-induced cell death or mutation. However, maintaining a proper balance of activity both within and between these pathways is crucial for a favourable response of an organism to alkylating agents. Furthermore, the response of an individual to alkylating agents can vary considerably from tissue to tissue and from person to person, pointing to genetic and epigenetic mechanisms that modulate alkylating agent toxicity

    Neurogenic lower urinary tract dysfunction: Clinical management recommendations of the Neurologic Incontinence committee of the fifth International Consultation on Incontinence 2013

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    BACKGROUND: Evidence-based guidelines for the management of neurological disease and lower urinary tract dysfunction have been produced by the International Consultations on Incontinence (ICI). These are comprehensive guidelines, and were developed to have world-wide relevance. AIMS: To update clinical management of neurogenic bladder dysfunction from the recommendations of the fourth ICI, 2009. MATERIALS AND METHODS: A series of evidence reviews and updates were performed by members of the working group. The resulting guidelines were presented at the 2012 meeting of the European Association of Urology for consultation, and consequently amended to deliver evidence-based conclusions and recommendations in 2013. RESULTS: The current review is a synthesis of the conclusions and recommendations, including the algorithms for initial and specialized management of neurogenic lower urinary tract dysfunction. The pathophysiology is categorized according to the nature of onset of neurological disease and the part(s) of the nervous system affected. Assessment requires clinical evaluation, general investigations, and specialized testing. Treatment primarily focuses on ensuring safety of the patient and optimizing quality of life. Symptom management covers conservative and interventional measures to aid urine storage and bladder emptying, along with containment of incontinence. A multidisciplinary approach to management is essential. DISCUSSION: The review offers a pragmatic review of management in the context of complex pathophysiology and varied evidence base. Neurourol. Urodynam. 35:657-665, 2016. © 2016 Wiley Periodicals, Inc

    Neoplastic transformation of breast epithelial cells by genotoxic stress

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    <p>Abstract</p> <p>Background</p> <p>Exposure to genotoxic stresses such as radiation and tobacco smoke can cause increased cancer incidence rate as reflected in an in depth meta-analysis of data for women and breast cancer incidence. Published reports have indicated that exposures to low dose radiation and tobacco smoke are factors that contribute to the development of breast cancer. However, there is a scarcity of information on the combinatorial effects of low dose radiation and tobacco smoke on formation and progression of breast cancer. The combination of these two genotoxic insults can induce significant damage to the genetic material of the cells resulting in neoplastic transformation.</p> <p>Methods</p> <p>To study the effects of low dose ionizing radiation and tobacco smoke on breast cells, MCF 10A cells were treated either with radiation (Rad - 0.1 Gray) or cigarette smoke condensate (Csc - 10 microgram/ml of medium) or a combination of Rad + Csc. Following treatments, cells were analyzed for cell cycle distribution patterns and the ability to extrude the Hoechst 33342 dye. In addition, <it>in vitro </it>invasion and migration as well as mammosphere formation assays were performed. Finally, differential gene expression profiles were generated from the individual and combination treatment.</p> <p>Results</p> <p>Exposure of MCF 10A cells to the combination of radiation plus cigarette smoke condensate generated a neoplastic phenotype. The transformed phenotype promoted increased mammosphere numbers, altered cell cycle phases with a doubling of the population in S phase, and increased invasion and motility. Also, exclusion of Hoechst 33342 dye, a surrogate marker for increased ABC transporters, was observed, which indicates a possible increase in drug resistance. In addition, changes in gene expression include the up regulation of genes encoding proteins involved in metabolic pathways and inflammation.</p> <p>Conclusions</p> <p>The results indicate that when normal breast cells are exposed to low dose radiation in combination with cigarette smoke condensate a phenotype is generated that exhibits traits indicative of neoplastic transformation. More importantly, this is the first study to provide a new insight into a possible etiology for breast cancer formation in individuals exposed to low dose radiation and tobacco smoke.</p

    The Origins of Concentric Demyelination: Self-Organization in the Human Brain

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    Baló's concentric sclerosis is a rare atypical form of multiple sclerosis characterized by striking concentric demyelination patterns. We propose a robust mathematical model for Baló's sclerosis, sharing common molecular and cellular mechanisms with multiple sclerosis. A reconsideration of the analogies between Baló's sclerosis and the Liesegang periodic precipitation phenomenon led us to propose a chemotactic cellular model for this disease. Rings of demyelination appear as a result of self-organization processes, and closely mimic Baló lesions. According to our results, homogeneous and concentric demyelinations may be two different macroscopic outcomes of a single fundamental immune disorder. Furthermore, in chemotactic models, cellular aggressivity appears to play a central role in pattern formation

    Induction of viral and tumour specific CTL responses using antibody targeted HLA class I peptide complexes

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    The production of cytotoxic T cells with specificity for cancer cells is a rapidly evolving branch of cancer therapeutics. A variety of approaches aim to amplify anti-tumour cytotoxic T cell responses using purified peptides, tumour cell lysates or recombinant HLA/peptide complexes in differing antigen presenting systems. Using a two-step biotin-streptavidin antibody targeting system, recombinant HLA-class I/peptide complexes were attached to the surface of B cells via the anti-CD20 B9E9-scFvSA antibody-streptavidin fusion protein. Flow cytometry with a conformation dependant monoclonal antibody to HLA class I indicated that targeted HLA-class I/peptide complexes remain on the surface of B cells in culture for periods in excess of 72 h. PBMCs were stimulated in vitro for 8-14 days using the autologous B cells as antigen presenting cells. Following a single cycle of stimulation specific cytotoxic T cell responses to targeted HLA-A2 complexes containing the M1, BMLF1 and Melan A peptides could be demonstrated by tetramer staining and Cr release assays. With the HLA-A2/BMLF1 complex up to 2.99% of CD8+ve cells were tetramer positive producing 20% lysis (E : T 10 : 1) of CIR-A2 target cells in an in vitro cytotoxicity assay compared to baseline levels of 0.09% tetramer +ve and 2% lysis in the unstimulated population. PBMCs from a healthy donor treated with two cycles of stimulations with targeted HLA-A2/Melan A complexes, demonstrated expansion of the melanA tetramer +ve population from 0.03% to 1.4% producing 15% lysis of Melan A pulsed target cells. With further consideration to the key variables of HLA/peptide complex density, the ratio of stimulator to effector cells and optimum cytokine support, this system should offer an easy and effective method for the in vitro amplification of specific cytotoxic T cell responses and warrants development for the in vivo induction of cytotoxic T cell responses in cancer therapy

    Nonlinear stochastic evolution equations of second order with damping

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    Convergence of a full discretization of a second order stochastic evolution equation with nonlinear damping is shown and thus existence of a solution is established. The discretization scheme combines an implicit time stepping scheme with an internal approximation. Uniqueness is proved as well.Comment: This is the version of the article accepted for publication. The final publication is available at http://link.springer.co

    Next-gen sequencing identifies non-coding variation disrupting miRNA-binding sites in neurological disorders

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    Understanding the genetic factors underlying neurodevelopmental and neuropsychiatric disorders is a major challenge given their prevalence and potential severity for quality of life. While large-scale genomic screens have made major advances in this area, for many disorders the genetic underpinnings are complex and poorly understood. To date the field has focused predominantly on protein coding variation, but given the importance of tightly controlled gene expression for normal brain development and disorder, variation that affects non-coding regulatory regions of the genome is likely to play an important role in these phenotypes. Herein we show the importance of 3 prime untranslated region (3'UTR) non-coding regulatory variants across neurodevelopmental and neuropsychiatric disorders. We devised a pipeline for identifying and functionally validating putatively pathogenic variants from next generation sequencing (NGS) data. We applied this pipeline to a cohort of children with severe specific language impairment (SLI) and identified a functional, SLI-associated variant affecting gene regulation in cells and post-mortem human brain. This variant and the affected gene (ARHGEF39) represent new putative risk factors for SLI. Furthermore, we identified 3'UTR regulatory variants across autism, schizophrenia and bipolar disorder NGS cohorts demonstrating their impact on neurodevelopmental and neuropsychiatric disorders. Our findings show the importance of investigating non-coding regulatory variants when determining risk factors contributing to neurodevelopmental and neuropsychiatric disorders. In the future, integration of such regulatory variation with protein coding changes will be essential for uncovering the genetic causes of complex neurological disorders and the fundamental mechanisms underlying health and disease
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