142 research outputs found

    Dopamine promotes instrumental motivation, but reduces reward-related vigour.

    Get PDF
    We can be motivated when reward depends on performance, or merely by the prospect of a guaranteed reward. Performance-dependent (contingent) reward is instrumental, relying on an internal action-outcome model, whereas motivation by guaranteed reward may minimise opportunity cost in reward-rich environments. Competing theories propose that each type of motivation should be dependent on dopaminergic activity. We contrasted these two types of motivation with a rewarded saccade task, in patients with Parkinson's disease (PD). When PD patients were ON dopamine, they had greater response vigour (peak saccadic velocity residuals) for contingent rewards, whereas when PD patients were OFF medication, they had greater vigour for guaranteed rewards. These results support the view that reward expectation and contingency drive distinct motivational processes, and can be dissociated by manipulating dopaminergic activity. We posit that dopamine promotes goal-directed motivation, but dampens reward-driven vigour, contradictory to the prediction that increased tonic dopamine amplifies reward expectation

    Ascospore release and survival in Sclerotinia sclerotiorum

    Get PDF
    The release and survival of ascospores of a UK Sclerotinia sclerotiorum isolate were studied. Apothecia placed in a spore clock apparatus with different lighting regimes at 15 °C released ascospores continuously with an increasing rate for the duration of experiments (72–84 h). Spore release was not confined to light or dark periods in alternating regimes and occurred in continuous dark or light. Ascospores were released in both saturated air (90–95% rh) and at 65–75% rh. High temperature and rh were detrimental to ascospore survival but spore viability was maintained for longer periods than previously reported. The significance of these results in relation to disease control is discussed

    A new toolbox to distinguish the sources of spatial memory error

    Get PDF

    Num. 11

    Get PDF
    Emerging evidence suggests that dopamine may modulate learning and memory with important implications for understanding the neurobiology of memory and future therapeutic targeting. An influential hypothesis posits that dopamine biases reinforcement learning. More recent data also suggest an influence during both consolidation and retrieval. Eighteen Parkinson’s disease patients learned through feedback ON or OFF medication with memory tested 24 hours later ON or OFF medication (4 conditions, within-subjects design with matched healthy control group). Patients OFF medication during learning decreased in memory accuracy over the following 24 hours. In contrast to previous studies, however, dopaminergic medication during learning and testing did not affect expression of positive or negative reinforcement. Two further experiments were run without the 24-hour delay, but they too failed to reproduce effects of dopaminergic medication on reinforcement learning. While supportive of a dopaminergic role in consolidation, this study failed to replicate previous findings on reinforcement learning

    Evaluation of the benefits, harms and cost‐effectiveness of potential alternatives to iFOBT testing for colorectal cancer screening in Australia

    Get PDF
    The Australian National Bowel Cancer Screening Program (NBCSP) will fully roll‐out 2‐yearly screening using the immunochemical Faecal Occult Blood Testing (iFOBT) in people aged 50 to 74 years by 2020. In this study, we aimed to estimate the comparative health benefits, harms, and cost‐effectiveness of screening with iFOBT, versus other potential alternative or adjunctive technologies. A comprehensive validated microsimulation model, Policy1‐Bowel, was used to simulate a total of 13 screening approaches involving use of iFOBT, colonoscopy, sigmoidoscopy, computed tomographic colonography (CTC), faecal DNA (fDNA) and plasma DNA (pDNA), in people aged 50 to 74 years. All strategies were evaluated in three scenarios: (i) perfect adherence, (ii) high (but imperfect) adherence, and (iii) low adherence. When assuming perfect adherence, the most effective strategies involved using iFOBT (annually, or biennially with/without adjunct sigmoidoscopy either at 50, or at 54, 64 and 74 years for individuals with negative iFOBT), or colonoscopy (10‐yearly, or once‐off at 50 years combined with biennial iFOBT). Colorectal cancer incidence (mortality) reductions for these strategies were 51–67(74–80)% in comparison with no screening; 2‐yearly iFOBT screening (i.e. the NBCSP) would be associated with reductions of 51(74)%. Only 2‐yearly iFOBT screening was found to be cost‐effective in all scenarios in context of an indicative willingness‐to‐pay threshold of A50,000/lifeyearsaved(LYS);thisstrategywasassociatedwithanincrementalcosteffectivenessratioofA50,000/life‐year saved (LYS); this strategy was associated with an incremental cost‐effectiveness ratio of A2,984/LYS–A$5,981/LYS (depending on adherence). The fully rolled‐out NBCSP is highly cost‐effective, and is also one of the most effective approaches for bowel cancer screening in Australia

    Preoperative Cardiac Variables of Diastolic Dysfunction and Clinical Outcomes in Lung Transplant Recipients

    Get PDF
    Background. Orthotopic lung transplantation is now widely performed in patients with advanced lung disease. Patients with moderate or severe ventricular systolic dysfunction are typically excluded from lung transplantation; however, there is a paucity of data regarding the prognostic significance of abnormal left ventricular diastolic function and elevated pretransplant pulmonary pressures. Methods. We reviewed the characteristics of 111 patients who underwent bilateral and unilateral lung transplants from 200 to 2009 in order to evaluate the prognostic significance of preoperative markers of diastolic function, including invasively measured pulmonary capillary wedge pressure (PCWP) and echocardiographic variables of diastolic dysfunction including mitral A>E and A′>E′. Results. Out of 111 patients, 62 were male (56%) and average age was 54.0 ± 10.5 years. Traditional echocardiographic Doppler variables of abnormal diastolic function, including A′>E′ and A>E, did not predict adverse events (P=0.49). Mildly elevated pretransplant PCWP (16–20 mmHg) and moderately/severely elevated PCWP (>20 mmHg) were not associated with adverse clinical events after transplant (P=0.30). Additionally, all clinical endpoints did not show any statistical significance between the two groups. Conclusions. Pre-lung transplant invasive and echocardiographic findings of elevated pulmonary pressures and abnormal left ventricular diastolic function are not predictive of adverse posttransplant clinical events

    The ExPeCT (Examining Exercise, Prostate Cancer and Circulating Tumour Cells) trial: study protocol for a randomised controlled trial

    Get PDF
    Background: Prostate cancer (PrCa) is the second most common cancer in Ireland. Many men present with locally advanced or metastatic cancer for whom curative surgery is inappropriate. Advanced cancer patients are encouraged to remain physically active and therefore there is a need to investigate how patients with metastatic disease tolerate physical activity programmes. Physical activity reduces levels of systemic inflammatory mediators and so an aerobic exercise intervention may represent an accessible and cost-effective means of ameliorating the pro-inflammatory effects of obesity and subsequently decrease poor cancer-specific outcomes in this patient population. This study will assess the feasibility and safety of introducing a structured aerobic exercise intervention to an advanced cancer population. This study will also examine if the evasion of immune editing by circulating tumour cells (CTCs) is an exercise-modifiable mechanism in obese men with prostate cancer. Methods: This international multicentre prospective study will recruit men with metastatic prostate cancer. Participants will be recruited from centres in Dublin (Ireland) and London (UK). Participants will be divided into exposed and non-exposed groups based on body mass index (BMI) ≥ 25 kg/m2 and randomised to intervention and control groups. The exercise group will undertake a regular supervised aerobic exercise programme, whereas the control group will not. Exercise intensity will be prescribed based on a target heart rate monitored by a polar heart rate monitor. Blood samples will be taken at recruitment and at 3 and 6 months to examine the primary endpoint of platelet cloaking of CTCs. Participants will complete a detailed questionnaire to assess quality of life (QoL) and other parameters at each visit. Discussion The overall aim of the ExPeCT trial is to examine the relationship between PrCa, exercise, obesity, and systemic inflammation, and to improve the overall QoL in men with advanced disease. Results will inform future work in this area examining biological markers of prognosis in advanced prostate cancer. Trial registration Clinicaltrials.gov NLM identifier: NCT02453139. Registered on 12 May 2015. This document contains excerpts from the ExPeCT trial protocol Version 1.5, 28 July 2016

    IL10 and IL10 receptor gene variation and outcomes after unrelated and related hematopoietic cell transplantation.

    Get PDF
    BACKGROUND: Results of a previous study with human leukocyte antigen (HLA)-identical siblings showed individual and synergistic associations of single nucleotide polymorphisms in the promoter region of the recipient's IL10 gene and the donor's IL10 receptor beta (IL-10RB) gene with development of grades III-IV acute graft-versus-host disease (GVHD) after allogeneic hematopoietic cell transplantation. METHODS: In this study of 936 patients who had unrelated donors, genotypes of single nucleotide polymorphisms in the IL10 gene and the IL-10RB gene were evaluated as correlates with outcomes after transplantation. RESULTS: We found no statistically significant associations of polymorphisms at positions -3575, -2763, -1082, and -592 of the IL10 gene or codon 238 of the IL10RB gene with severe acute GVHD, extensive chronic GVHD or nonrelapse mortality after hematopoietic cell transplantation. Among HLA-matched unrelated pairs, the patient's IL10/-592 genotype and donor's IL10RB/c238 genotype showed trends suggesting individual and combined associations with grades III-IV acute GVHD similar to those observed among patients with HLA-identical sibling donors. CONCLUSIONS: Although genetic variation in IL10 pathway affects risk of acute GVHD and non-relapse mortality in HLA-identical sibling transplants, the current results indicate that genetic variation in the IL10 pathway does not significant affect these outcomes in unrelated donor transplants suggesting that the strength of the alloimmune response in the latter exceeds the anti-inflammatory activity of IL10
    corecore