191 resultados para Gregor Mendel


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Es gibt zunehmend Beispiele, die belegen, dass die Neuroökonomie als Kombination von ökonomischer Entscheidungstheorie und Neurowissenschaften einen wichtigen Beitrag zur Psychotherapie-Forschung leisten kann. Die Berührungspunkte der beiden Disziplinen sind vielfältig: • Neuroökonomie benutzt Verhaltensexperimente, die es erlauben, komplexes menschliches Verhalten zu untersuchen. Psychotherapie verändert komplexes menschliches Verhalten. Zur Verbesserung der Diagnostik und der Evaluation von Therapieergebnissen können einfache neuroökonomische Experimente einen wichtigen Beitrag leisten. Die experimentelle Messung von zeitlichen, sozialen und Unsicherheitspräferenzen ist besonders geeignet, psychische Störungen zu charakterisieren. • Neuroökonomie ist eine Wissenschaft der menschlichen Motivation. Das Verständnis von bewussten und unbewussten Motivationsfaktoren erlaubt es Psychotherapeutinnen, die Komplexität und Tiefe der Probleme ihrer Patientinnen zu erfassen. • Neuroökonomie ist eine Sozialwissenschaft. Beziehungsprobleme gehören zu den häufigsten Klagen von Patientinnen mit psychischen Störungen, soziale Stressoren sind wichtige Ursachen psychischer Störungen und die therapeutische Beziehung ist der wichtigste Wirkfaktor der Psychotherapie. Die neuroökonomische Erforschung des Sozialverhaltens kann deshalb die Psychotherapie auf unterschiedlichen Ebenen inspirieren. • Neuroökonomie ist eine Neurowissenschaft. Psychotherapie-Forschung beschäftigt sich zunehmend mit Neuroplastizität, insbesondere mit den Effekten von Psychotherapie auf die Funktion und die Struktur des Gehirns. Der neuroökonomische Forschungsansatz macht es möglich, komplexe neuronale Funktionsstörungen bei psychischen Krankheiten zu identifizieren und ihre Modifikation durch Psychotherapie sichtbar zu machen. • Neuroökonomie ist eine umfassende Wissenschaft des menschlichen Verhaltens. Moderne Psychotherapie hat den Anspruch, psychische Störungen auf dem Hintergrund eines bio-psycho-soziales Krankheitsmodells zu verstehen und zu behandeln. Die Neuroökonomie kann einen Beitrag leisten, psychotherapeutische Krankheitsmodelle wissenschaftlich zu fundieren. Die ökonomische Entscheidungstheorie ermöglicht es, die Wechselwirkungen und Synergien von psychotherapeutischer Arbeit, somatischen Behandlungen und sozialen Rahmenbedingungen abzuschätzen. Folgende Eigenschaften schränken die Anwendbarkeit von neuroökonomischen Ansätzen in der Psychotherapie-Forschung allerdings ein: • Das Präferenz-Konzept geht von einer stabilen Verhaltensprädisposition aus. Wechsel von Präferenzen und stark situationsabhängiges Verhalten kann nur beschränkt modelliert werden. • In den meisten neuroökonomischen Experimenten wird Geld als allgemein gültiger Anreiz verwendet. Diese Methodik erlaubt es nicht, reizspezifisches Verhalten zu untersuchen. • Die Neuroökonomie abstrahiert soziale Beziehungen, um sie wissenschaftlich fassbar zu machen. Gewisse Beziehungsaspekte wie beispielsweise die Rolle von Gestik und Mimik können mit dieser Methodik nicht untersucht werden. • Die klassische ökonomische Entscheidungstheorie ist besonders geeignet, „kalte“, überlegte Entscheidungen zu verstehen. Impulsives und zeitinkonsistentes Verhalten kann mit dieser Theorie nur ungenügend beschrieben werden. Neuroökonomie ist eine junge Wissenschaft mit grossem Entwicklungspotential. Führende theoretische und Experimentalökonomen sind daran, Theorie und Forschungsmethodik zu erweitern, um situations- und reizspezifische Faktoren besser zu berücksichtigen und das „heisse“ Ende des Spektrums von Entscheidungsfindungen besser zu verstehen.

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Obsessive-compulsive disorder (OCD) is a disabling, mostly chronic, psychiatric condition with significant social and economic impairments and is a major public health issue. However, numerous patients are resistant to currently available pharmacological and psychological interventions. Given that recent animal studies and magnetic resonance spectroscopy research points to glutamate dysfunction in OCD, we investigated the metabotropic glutamate receptor 5 (mGluR5) in patients with OCD and healthy controls. We determined mGluR5 distribution volume ratio (DVR) in the brain of ten patients with OCD and ten healthy controls by using [11C]ABP688 positron-emission tomography. As a clinical measure of OCD severity, the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) was employed. We found no significant global difference in mGluR5 DVR between patients with OCD and healthy controls. We did, however, observe significant positive correlations between the Y-BOCS obsession sub-score and mGluR5 DVR in the cortico-striatal-thalamo-cortical brain circuit, including regions of the amygdala, anterior cingulate cortex, and medial orbitofrontal cortex (Spearman's ρ's⩾ = 0.68, p < 0.05). These results suggest that obsessions in particular might have an underlying glutamatergic pathology related to mGluR5. The research indicates that the development of metabotropic glutamate agents would be useful as a new treatment for OCD.

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Objective Albeit clear advances in the treatment of SLE, many patients still present with refractory lupus nephritis requiring new treatment strategies for this disease. Here we determined whether reduced doses of the topoisomerase I inhibitor irinotecan, which is known as chemotherapeutic agent, were able to suppress SLE in NZB/W F1 mice. We further evaluated the potential mechanism how irinotecan influenced the course of SLE. Methods NZB/W F1 mice were treated with low dose irinotecan either from week 24 of age or from established glomerulonephritis defined by a proteinuria ≥grade 3+. Binding of anti-dsDNA antibodies was measured by ELISA; and DNA relaxation was visualized by gel electrophoresis. Results Significantly reduced irinotecan dosages improved lupus nephritis and prolonged survival in NZB/W F1 mice. The lowest dose successfully used for the treatment of established murine lupus nephritis was more than 50 times lower than the dose usually applied for chemotherapy in humans. As a mechanism, low dose irinotecan reduced B cell activity; however, the levels of B cell activity in irinotecan-treated mice were similar to those in Balb/c mice of the same age suggesting that irinotecan did not induce a clear immunosuppression. In addition, incubation of double-stranded (ds) DNA with topoisomerase I increased binding of murine and human anti-dsDNA antibodies showing for the first time that relaxed DNA is more susceptible to anti-dsDNA antibody binding. This effect was reversed by addition of the topoisomerase I inhibitor camptothecin. Conclusion Our results propose topoisomerase I inhibitors as a novel and targeted therapy for SLE. © 2014 American College of Rheumatology.

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Dopaminergic signals play a mathematically precise role in reward-related learning, and variations in dopaminergic signaling have been implicated in vulnerability to addiction. Here, we provide a detailed overview of the relationship between theoretical, mathematical, and experimental accounts of phasic dopamine signaling, with implications for the role of learning-related dopamine signaling in addiction and related disorders. We describe the theoretical and behavioral characteristics of model-free learning based on errors in the prediction of reward, including step-by-step explanations of the underlying equations. We then use recent insights from an animal model that highlights individual variation in learning during a Pavlovian conditioning paradigm to describe overlapping aspects of incentive salience attribution and model-free learning. We argue that this provides a computationally coherent account of some features of addiction.

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Understanding the links between genetic, epigenetic and non-genetic factors throughout the lifespan and across generations and their role in disease susceptibility and disease progression offer entirely new avenues and solutions to major problems in our society. To overcome the numerous challenges, we have come up with nine major conclusions to set the vision for future policies and research agendas at the European level.

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Background: A relationship between bulimia nervosa (BN) and reward-related behavior is supported by several lines of evidence. The dopaminergic dysfunctions in the processing of reward-related stimuli have been shown to be modulated by the neurotrophin brain derived neurotrophic factor (BDNF) and the hormone leptin. Methods: Using a randomized, double-blind, placebo-controlled, crossover design, a reward learning task was applied to study the behavior of 20 female subjects with remitted BN (rBN) and 27 female healthy controls under placebo and catecholamine depletion with alpha-methyl-para-tyrosine (AMPT). The plasma levels of BDNF and leptin were measured twice during the placebo and the AMPT condition, immediately before and 1 h after a standardized breakfast. Results: AMPT-induced differences in plasma BDNF levels were positively correlated with the AMPT-induced differences in reward learning in the whole sample (p = 0.05). Across conditions, plasma BDNF levels were higher in rBN subjects compared to controls (diagnosis effect; p = 0.001). Plasma BDNF and leptin levels were higher in the morning before compared to after a standardized breakfast across groups and conditions (time effect; p < 0.0001). The plasma leptin levels were higher under catecholamine depletion compared to placebo in the whole sample (treatment effect; p = 0.0004). Conclusions: This study reports on preliminary findings that suggest a catecholamine-dependent association of plasma BDNF and reward learning in subjects with rBN and controls. A role of leptin in reward learning is not supported by this study. However, leptin levels were sensitive to a depletion of catecholamine stores in both rBN and controls.

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Background: Despite immense efforts into development of new antidepressant drugs, the increases of serotoninergic and catechominergic neurotransmission have remained the two major pharmacodynamic principles of current drug treatments for depression. Consequently, psychopathological or biological markers that predict response to drugs that selectively increase serotonin and/or catecholamine neurotransmission hold the potential to optimize the prescriber’s selection among currently available treatment options. The aim of this study was to elucidate the differential symptomatology and neurophysiology in response to reductions in serotonergic versus catecholaminergic neurotransmission in subjects at high risk of depression recurrence. Methods: Using identical neuroimaging procedures with [18F] fluorodeoxyglucose positron emission tomography after tryptophan depletion (TD) and catecholamine depletion (CD), subjects with remitted depression were compared to healthy controls in a double-blind, randomized, crossover design. Results: While TD induced significantly more depressed mood, sadness and hopelessness than CD, CD induced more inactivity, concentration difficulties, lassitude and somatic anxiety than TD. CD specifically increased glucose metabolism in the bilateral ventral striatum and decreased glucose metabolism in the bilateral orbitofrontal cortex, whereas TD specifically increased metabolism in the right prefrontal cortex and the posterior cingulate cortex (PCC). While we found direct associations between changes in brain metabolism and induced depressive symptoms following CD, the relationship between neural activity and symptoms was less clear after TD. Conclusions: In conclusion, this study showed that serotonin and catecholamines play common and differential roles in the pathophysiology of depression.

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Although posttraumatic stress disorder (PTSD) is associated with a variety of structural and functional brain changes, the molecular pathophysiological mechanisms underlying these macroscopic alterations are unknown. Recent studies support the existence of an altered excitation-inhibition balance in PTSD. Further, there is preliminary evidence from blood-sample studies suggesting heightened oxidative stress in PTSD, potentially leading to neural damage through excessive brain levels of free radicals. In this study we investigated PTSD (n=12) and non-PTSD participants (n=17) using single-voxel proton magnetic resonance spectroscopy (MRS) in dorsolateral prefrontal cortex (DLPFC) and anterior cingulate cortex (ACC). We found significantly higher levels of γ-amino butyric acid (GABA) (a primary inhibitory neurotransmitter) and glutathione (a marker for neuronal oxidative stress) in PTSD participants. Atypically high prefrontal inhibition as well as oxidative stress may be involved in the pathogenesis of PTSD.

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Patient-reported outcome (PRO) refers to measures that emphasize the subjective view of patients about their health-related conditions and behaviors. Typically, PROs include self-report questionnaires and clinical interviews. Defining PROs for borderline personality disorder (BPD) is particularly challenging given the disorder's high symptomatic heterogeneity, high comorbidity with other psychiatric conditions, highly fluctuating symptoms, weak correlations between symptoms and functional outcomes, and lack of valid and reliable experimental measures to complement self-report data. Here, we provide an overview of currently used BPD outcome measures and discuss them from clinical, psychometric, experimental, and patient perspectives. In addition, we review the most promising leads to improve BPD PROs, including the DSM-5 Section III, the Recovery Approach, Ecological Momentary Assessments, and novel experimental measures of social functioning that are associated with functional and social outcomes.

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Depressionen verursachen immer höhere Kosten für die Gesellschaft. Das liegt auch an einer falschen Versorgung: Die Krankheit sollte früher und gezielter behandelt werden.

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The aim of our study was to evaluate the quality of histo- and cytomorphological features of PAXgene-fixed specimens and their suitability for histomorphological classification in comparison to standard formalin fixation. Fifteen colon cancer tissues were collected, divided into two mirrored samples and either formalin fixed (FFPE) or PAXgene fixed (PFPE) before paraffin embedding. HE- and PAS-stained sections were scanned and evaluated in a blinded, randomised ring trial by 20 pathologists from Europe and the USA using virtual microscopy. The pathologists evaluated histological grading, histological subtype, presence of adenoma, presence of lymphovascular invasion, quality of histomorphology and quality of nuclear features. Statistical analysis revealed that the reproducibility with regard to grading between both fixation methods was rather satisfactory (weighted kappa statistic (k w) = 0.73 (95 % confidence interval (CI), 0.41-0.94)), with a higher agreement between the reference evaluation and the PFPE samples (k w = 0.86 (95 % CI, 0.67-1.00)). Independent from preservation method, inter-observer reproducibility was not completely satisfactory (k w = 0.60). Histomorphological quality parameters were scored equal or better for PFPE than for FFPE samples. For example, overall quality and nuclear features, especially the detection of mitosis, were judged significantly better for PFPE cases. By contrast, significant retraction artefacts were observed more frequently in PFPE samples. In conclusion, our findings suggest that the PAXgene Tissue System leads to excellent preservation of histomorphology and nuclear features of colon cancer tissue and allows routine morphological diagnosis.

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INTRODUCTION Treatment failure in acute myeloid leukemia is probably caused by the presence of leukemia initiating cells, also referred to as leukemic stem cells, at diagnosis and their persistence after therapy. Specific identification of leukemia stem cells and their discrimination from normal hematopoietic stem cells would greatly contribute to risk stratification and could predict possible relapses. RESULTS For identification of leukemic stem cells, we developed flow cytometric methods using leukemic stem cell associated markers and newly-defined (light scatter) aberrancies. The nature of the putative leukemic stem cells and normal hematopoietic stem cells, present in the same patient's bone marrow, was demonstrated in eight patients by the presence or absence of molecular aberrancies and/or leukemic engraftment in NOD-SCID IL-2Rγ-/- mice. At diagnosis (n=88), the frequency of the thus defined neoplastic part of CD34+CD38- putative stem cell compartment had a strong prognostic impact, while the neoplastic parts of the CD34+CD38+ and CD34- putative stem cell compartments had no prognostic impact at all. After different courses of therapy, higher percentages of neoplastic CD34+CD38- cells in complete remission strongly correlated with shorter patient survival (n=91). Moreover, combining neoplastic CD34+CD38- frequencies with frequencies of minimal residual disease cells (n=91), which reflect the total neoplastic burden, revealed four patient groups with different survival. CONCLUSION AND PERSPECTIVE Discrimination between putative leukemia stem cells and normal hematopoietic stem cells in this large-scale study allowed to demonstrate the clinical importance of putative CD34+CD38- leukemia stem cells in AML. Moreover, it offers new opportunities for the development of therapies directed against leukemia stem cells, that would spare normal hematopoietic stem cells, and, moreover, enables in vivo and ex vivo screening for potential efficacy and toxicity of new therapies.