1,975 research outputs found

    Herbivore-induced emissions of methanol and ethylene: volatile signals in the defense response of Nicotiana attenuata

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    Pflanzen sind trotz ihrer sessilen Lebensweise weitaus aktiver als es den Anschein hat. In einem sich ständig verändernden Lebensraum passen Pflanzen kontinuierlich ihren Phänotyp den herrschenden Umweltbedingungen an. Um auf abiotische und biotische Stressfaktoren reagieren zu können, haben Pflanzen Erkennungs- und Regelungsmechanismen entwickelt, die es ihnen erlauben, gezielt und schnell auf momentan wirkende Umweltfaktoren zu reagieren. Mechanische Verwundung stellt dabei einen Reiz dar, der sowohl durch die unbelebte als auch durch die belebte Umwelt ausgelöst werden kann. Für die Pflanze ist es relevant diese voneinander zu unterscheiden. Zellwandbestandteile von Pilzen und Bakterien oder spezifische Abbauprodukte der Verdauungsenzyme angreifender Insekten sind für biotische Angreifer charakteristische Signalmoleküle, die die Pflanze erkennt und daraufhin eine spezifische, je nach Stressor unterschiedliche, induzierte Abwehrreaktion auslöst. Die Aktivierung bestimmter Abwehrmechanismen gegen Herbivorie, wie die Akkumulation toxischer Substanzen oder die Aktivierung verdauungshemmender Enzyme, erfolgt hauptsächlich über das Pflanzenhormon Jasmonsäure (JS) und dessen Derivate. Die Regulation der Abwehr findet jedoch nicht ausschliesslich über JS statt. Besonders die Vernetzung verschiedener Signalkaskaden ermöglicht der Pflanze eine spezielle Anpassung ihrer Reaktion auf die einwirkenden Reize

    Use of silenced plants in allelopathy bioassays: a novel approach

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    Pectin methylesterase NaPME1 contributes to the emission of methanol during insect herbivory and to the elicitation of defence responses in Nicotiana attenuata

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    Pectin methylesterases (PMEs) catalyse the demethylation of pectin within plant cell walls, releasing methanol (MeOH) in the process. Thus far, PMEs have been found to be involved in diverse processes such as plant growth and development and defence responses against pathogens. Herbivore attack increases PME expression and activity and MeOH emissions in several plant species. To gain further insights into the role of PMEs in defence responses against herbivores, the expression of a Manduca sexta oral secretion (OS)-inducible PME in Nicotiana attenuata (NaPME1) was silenced by RNA interference (RNAi)-mediated gene silencing. Silenced lines (ir-pme) showed 50% reduced PME activity in leaves and 70% reduced MeOH emissions after OS elicitation compared with the wild type (WT), demonstrating that the herbivore-induced MeOH emissions originate from the demethylation of pectin by PME. In the initial phase of the OS-induced jasmonic acid (JA) burst (first 30 min), ir-pme lines produced WT levels of this hormone and of jasmonyl-isoleucine (JA-Ile); however, these levels were significantly reduced in the later phase (60–120 min) of the burst. Similarly, suppressed levels of the salicylic acid (SA) burst induced by OS elicitation were observed in ir-pme lines even though wounded ir-pme leaves contained slightly increased amounts of SA. This genotype also presented reduced levels of OS-induced trypsin proteinase inhibitor activity in leaves and consistently increased M. sexta larvae performance compared with WT plants. These latter responses could not be recovered by application of exogenous MeOH. Together, these results indicated that PME contributes, probably indirectly by affecting cell wall properties, to the induction of anti-herbivore responses

    Humour interventions for patients in palliative care-a randomized controlled trial.

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    PURPOSE: The effect of humour on end-of-life patients could be beneficial and is worth investigating. However, data on humour interventions for patients in palliative care are scarce. This study evaluated the effects of a humour intervention in a palliative care setting. METHODS: A two-step intervention was developed based on the humour habits programme by McGhee. Patients were assisted to remember funny episodes from their past and recognize humorous aspects of the present and encouraged to produce humour. The intervention and control group completed questionnaires on life satisfaction, cheerfulness, symptom burden, and perceived stress and if possible gave saliva samples to investigate oxytocin levels. The study was a randomized controlled monocentre study on patients treated in a palliative care ward. Participants had to be conscious and alert enough to complete data collection. Overall, 55 patients were included and randomized to the intervention or control group. RESULTS: Parameters in the control group did not change significantly. In the intervention group, seriousness, bad mood, and stress were reduced. Cheerfulness increased significantly after the intervention. However, the methodologically complex intervention setting was too exhausting for the majority of patients. CONCLUSION: Patients who were able to participate benefited from the effects of the intervention on multiple levels. For future research simple interventions, biomarkers for well-being and assessments by staff or proxies are needed to include patients with reduced cognitive and physical performance status at the end of their lives. TRIAL REGISTRATION: DRKS00028978 German Registry of Clinical Studies

    Isolation of Salmonella enterica in seropositive classified finishing pig herds

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    The aim of this study was to assess the probability of detecting Salmonella from pen faecal samples in seropositive classified finishing pig herds. The study involved 77 herds from Denmark (20), the Netherlands (20), Greece (17) and Germany (20). The serological herd status was determined by the blood- sampling of 50 finishing pigs. Bacteriological sampling was performed by 20 pen faecal samples per herd. Over-all, 47 % of the blood samples had an OD% larger than 10 and 23 % larger than 40. Salmonella was isolated from 135 (9.3 %) pen faecal samples in 32 herds (42 %). Twenty-eight of these herds (87.5 %) had a within-herd seroprevalence larger than 50% at sample cut-off OD%\u3e10. A correlation coefficient of 0.62 was found between the proportion of culture positive- and seropositive samples in a herd at cut-off OD % \u3e 10 and of 0.58 at cut-off OD % \u3e 40. Due to the low sensitivity of culture methods, apparent ‘false positive’ serological results may well represent real infections not detected by bacteriological testing. In this study, there was an increasing probability of recovering Salmonella with increasing within-herd seroprevalence

    Nocturnal temperature controlled laminar airflow for treating atopic asthma: a randomised controlled trial

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       Objective To determine whether environmental control using nocturnal temperature controlled laminar airflow (TLA) treatment could improve the quality of life of patients with persistent atopic asthma. &lt;br&gt; &lt;br&gt;Design Randomised, double-blind, placebo-controlled, parallel-group trial. &lt;br&gt; &lt;br&gt;Setting Nineteen European asthma clinics. &lt;br&gt; &lt;br&gt;Participants 312 patients aged 7-70 with inadequately controlled persistent atopic asthma. &lt;br&gt; &lt;br&gt;Main outcome measure Proportion of patients with an increase of &amp;gt;= 0.5 points in asthma quality of life score after 1 year of treatment. &lt;br&gt; &lt;br&gt;Results TLA devices were successfully installed in the bedrooms of 282 (90%) patients included in the primary efficacy analysis. There was a difference in treatment response rate between active (143 of 189, 76%) and placebo (56 of 92, 61%) groups, difference 14.8% (95% CI 3.1 to 26.5, p=0.02).(3) In patients aged &amp;gt;= 12, on whom the study was powered, the difference in response rate was similar-active 106 of 143 (74%), placebo 42 of 70 (60%), difference 14.1% (0.6 to 27.7, p=0.059). There was a difference between groups in fractional exhaled nitric oxide change of -7.1 ppb (-13.6 to -0.7, p=0.03). Active treatment was associated with less increase in cat-specific IgE than placebo. There was no difference in adverse event rates between treatment groups. &lt;br&gt; &lt;br&gt;Conclusion Inhalant exposure reduction with TLA improves quality of life, airway inflammation and systemic allergy in patients with persistent atopic asthma. TLA may be a treatment option for patients with inadequately controlled persistent atopic asthma.funding agencies|Airsonett AB||National Institute for Health Research||National Institute for Health Research Biomedical Research Centre||MRC||Asthma UK Centre in Allergic Mechanisms of Asthma||</p

    Model evaluation for glycolytic oscillations in yeast biotransformations of xenobiotics

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    Anaerobic glycolysis in yeast perturbed by the reduction of xenobiotic ketones is studied numerically in two models which possess the same topology but different levels of complexity. By comparing both models' predictions for concentrations and fluxes as well as steady or oscillatory temporal behavior we answer the question what phenomena require what kind of minimum model abstraction. While mean concentrations and fluxes are predicted in agreement by both models we observe different domains of oscillatory behavior in parameter space. Generic properties of the glycolytic response to ketones are discussed

    Neurotophin Receptor p75NTR Regulates Immune Function of Plasmacytoid Dendritic Cells

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    Plasmacytoid dendritic cells (pDCs) regulate innate and adaptive immunity. Neurotrophins and their receptors control the function of neuronal tissue. In addition, they have been demonstrated to be part of the immune response but little is known about the effector immune cells involved. We report, for the first time, the expression and immune-regulatory function of the low affinity neurotrophin receptor p75 neurotrophin receptor (p75NTR) by the antigen-presenting pDCs, mediated by toll-like receptor (TLR) 9 activation and differential phosphorylation of interferon regulatory factor 3 and 7. The modulation of p75NTR on pDCs significantly influences disease progression of asthma in an ovalbumin-induced mouse model mediated by the TLR9 signaling pathway. p75NTR activation of pDCs from patients with asthma increased allergen-specific T cell proliferation and cytokine secretion in nerve growth factor concentration-dependent manner. Further, p75NTR activation of pDCs delayed the onset of autoimmune diabetes in RIP-CD80GP mice and aggravated graft-versus-host disease in a xenotransplantation model. Thus, p75NTR signaling on pDCs constitutes a new and critical mechanism connecting neurotrophin signaling and immune response regulation with great therapeutic potential for a variety of immune disorders

    Little in Norway: a prospective longitudinal community-based cohort from pregnancy to child age 18 months

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    The Little in Norway (LiN) project is a cross-disciplinary prospective longitudinal study starting in pregnancy. It was set up to investigate maternal and paternal mental health functioning in the transition to parenthood, detect pathways to healthy and aberrant child development and generate new knowledge about mechanisms underlying differential child mental health susceptibility.publishedVersio
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