128 research outputs found

    Boundaries of Semantic Distraction: Dominance and Lexicality Act at Retrieval

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    Three experiments investigated memory for semantic information with the goal of determining boundary conditions for the manifestation of semantic auditory distraction. Irrelevant speech disrupted the free recall of semantic category-exemplars to an equal degree regardless of whether the speech coincided with presentation or test phases of the task (Experiment 1) and occurred regardless of whether it comprised random words or coherent sentences (Experiment 2). The effects of background speech were greater when the irrelevant speech was semantically related to the to-be-remembered material, but only when the irrelevant words were high in output dominance (Experiment 3). The implications of these findings in relation to the processing of task material and the processing of background speech is discussed

    Probe-Based Confocal Laser Endomicroscopy to Guide Real-Time Endoscopic Therapy in Barrett's Esophagus with Dysplasia

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    Probe-based confocal laser endomicroscopy (pCLE) is a novel imaging technique which utilizes a low-power laser light passed through a fiber-optic bundle, within a miniprobe that is advanced into the working channel, to obtain microscopic images of the mucosa. This allows the endoscopist to evaluate the microarchitecture of the gastrointestinal epithelium in real time. At this time pCLE cannot replace histopathology, but it can provide diagnostic information as well as guide therapeutic management in patients with Barrett's esophagus (BE) with high-grade dysplasia (HGD). We describe a retrospective case series in which four patients with BE and biopsy-proven HGD underwent endoscopy with pCLE to direct real-time endoscopic ablation therapy and/or endoscopic mucosal resection (EMR), which was performed in conjunction with pCLE. All four patients had pCLE showing features of HGD. After either EMR or radiofrequency ablation (RFA), pCLE was again used to evaluate the margins after therapy to assure accuracy. In one case, pCLE had features of dysplasia at the margin and further repeat EMR was immediately performed. Another case had a normal-appearing esophagus, but pCLE found features of BE in discrete areas and targeted biopsies were performed, which confirmed BE. This patient subsequently underwent RFA therapy of the residual areas of BE. In conclusion, in patients with BE and dysplasia, pCLE is an effective tool used to target biopsies, guide endoscopic therapy and assess the accuracy of EMR or RFA

    Eosinophilic gastroenteritis in a young girl – long term remission under Montelukast

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    BACKGROUND: Eosinophilic gastrointestinal disorders are an emerging disease entity characterized by eosinophilic infiltration of the intestinal wall. Oral steroids can be still considered as first line treatment. Unfortunately relapses are quite common. Usually long term low-dose prednisone or immunosuppressive therapy is required, which is especially problematic in young patients. Thus a reliable steroid sparing agent with low side effects suitable for long term use is needed. There are strong hints to a similar pathophysiology of eosinophilic gastrointestinal disorders to that of asthma. Indeed leukotriene D4 plays an important role in the recruitment of eosinophils into the intestinal tissue causing damage. This patho-mechanism provides the rationale for the treatment with a leukotriene D4 receptor antagonist. Recently there have been first reports about successful short term use of Montelukast in eosinophilic gastrointestinal disorders. CASE PRESENTATION: We report the case of a 17 year old girl with a long history of severe abdominal complaints leading to several hospitalizations in the past. Mimicking the picture of an intestinal tuberculosis she received an anti mycobacterial treatment without any success. Marked eosinophilia in blood, ascites and tissue samples of the intestinal tract finally lead to the diagnosis eosinophilic gastroenteritis. Tapering off prednisone caused another severe episode of abdominal pain. At that point leukotriene antagonist Montelukast was started at a dose of 10 mg once daily. Steroids could be tapered off completely within six weeks. The patient has been free of symptoms for over two years by now. Routine examinations, blood tests and endoscopy have rendered regular results. So far no side effects were noted. CONCLUSION: Here report about successful long term remission of eosinophilic gastroenteritis under Montelukast. Further randomized control trials are required to asses the full benefits of Montelukast therapy in the whole spectrum of eosinophilic gastrointestinal disorders

    Candidate Glutamatergic Neurons in the Visual System of Drosophila

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    The visual system of Drosophila contains approximately 60,000 neurons that are organized in parallel, retinotopically arranged columns. A large number of these neurons have been characterized in great anatomical detail. However, studies providing direct evidence for synaptic signaling and the neurotransmitter used by individual neurons are relatively sparse. Here we present a first layout of neurons in the Drosophila visual system that likely release glutamate as their major neurotransmitter. We identified 33 different types of neurons of the lamina, medulla, lobula and lobula plate. Based on the previous Golgi-staining analysis, the identified neurons are further classified into 16 major subgroups representing lamina monopolar (L), transmedullary (Tm), transmedullary Y (TmY), Y, medulla intrinsic (Mi, Mt, Pm, Dm, Mi Am), bushy T (T), translobula plate (Tlp), lobula intrinsic (Lcn, Lt, Li), lobula plate tangential (LPTCs) and lobula plate intrinsic (LPi) cell types. In addition, we found 11 cell types that were not described by the previous Golgi analysis. This classification of candidate glutamatergic neurons fosters the future neurogenetic dissection of information processing in circuits of the fly visual system

    Localized direction selective responses in the dendrites of visual interneurons of the fly

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    <p>Abstract</p> <p>Background</p> <p>The various tasks of visual systems, including course control, collision avoidance and the detection of small objects, require at the neuronal level the dendritic integration and subsequent processing of many spatially distributed visual motion inputs. While much is known about the pooled output in these systems, as in the medial superior temporal cortex of monkeys or in the lobula plate of the insect visual system, the motion tuning of the elements that provide the input has yet received little attention. In order to visualize the motion tuning of these inputs we examined the dendritic activation patterns of neurons that are selective for the characteristic patterns of wide-field motion, the lobula-plate tangential cells (LPTCs) of the blowfly. These neurons are known to sample direction-selective motion information from large parts of the visual field and combine these signals into axonal and dendro-dendritic outputs.</p> <p>Results</p> <p>Fluorescence imaging of intracellular calcium concentration allowed us to take a direct look at the local dendritic activity and the resulting local preferred directions in LPTC dendrites during activation by wide-field motion in different directions. These 'calcium response fields' resembled a retinotopic dendritic map of local preferred directions in the receptive field, the layout of which is a distinguishing feature of different LPTCs.</p> <p>Conclusions</p> <p>Our study reveals how neurons acquire selectivity for distinct visual motion patterns by dendritic integration of the local inputs with different preferred directions. With their spatial layout of directional responses, the dendrites of the LPTCs we investigated thus served as matched filters for wide-field motion patterns.</p

    Glutamate, GABA and Acetylcholine Signaling Components in the Lamina of the Drosophila Visual System

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    Synaptic connections of neurons in the Drosophila lamina, the most peripheral synaptic region of the visual system, have been comprehensively described. Although the lamina has been used extensively as a model for the development and plasticity of synaptic connections, the neurotransmitters in these circuits are still poorly known. Thus, to unravel possible neurotransmitter circuits in the lamina of Drosophila we combined Gal4 driven green fluorescent protein in specific lamina neurons with antisera to γ-aminobutyric acid (GABA), glutamic acid decarboxylase, a GABAB type of receptor, L-glutamate, a vesicular glutamate transporter (vGluT), ionotropic and metabotropic glutamate receptors, choline acetyltransferase and a vesicular acetylcholine transporter. We suggest that acetylcholine may be used as a neurotransmitter in both L4 monopolar neurons and a previously unreported type of wide-field tangential neuron (Cha-Tan). GABA is the likely transmitter of centrifugal neurons C2 and C3 and GABAB receptor immunoreactivity is seen on these neurons as well as the Cha-Tan neurons. Based on an rdl-Gal4 line, the ionotropic GABAA receptor subunit RDL may be expressed by L4 neurons and a type of tangential neuron (rdl-Tan). Strong vGluT immunoreactivity was detected in α-processes of amacrine neurons and possibly in the large monopolar neurons L1 and L2. These neurons also express glutamate-like immunoreactivity. However, antisera to ionotropic and metabotropic glutamate receptors did not produce distinct immunosignals in the lamina. In summary, this paper describes novel features of two distinct types of tangential neurons in the Drosophila lamina and assigns putative neurotransmitters and some receptors to a few identified neuron types

    Columnar cells necessary for motion responses of wide-field visual interneurons in Drosophila

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    Wide-field motion-sensitive neurons in the lobula plate (lobula plate tangential cells, LPTCs) of the fly have been studied for decades. However, it has never been conclusively shown which cells constitute their major presynaptic elements. LPTCs are supposed to be rendered directionally selective by integrating excitatory as well as inhibitory input from many local motion detectors. Based on their stratification in the different layers of the lobula plate, the columnar cells T4 and T5 are likely candidates to provide some of this input. To study their role in motion detection, we performed whole-cell recordings from LPTCs in Drosophila with T4 and T5 cells blocked using two different genetically encoded tools. In these flies, motion responses were abolished, while flicker responses largely remained. We thus demonstrate that T4 and T5 cells indeed represent those columnar cells that provide directionally selective motion information to LPTCs. Contrary to previous assumptions, flicker responses seem to be largely mediated by a third, independent pathway. This work thus represents a further step towards elucidating the complete motion detection circuitry of the fly

    Flavonoid and lignan intake in relation to bladder cancer risk in the European Prospective Investigation into Cancer and Nutrition (EPIC) study

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    Item does not contain fulltextBACKGROUND: There is growing evidence of the protective role of dietary intake of flavonoids and lignans on cancer, but the association with bladder cancer has not been thoroughly investigated in epidemiological studies. We evaluated the association between dietary intakes of total and subclasses of flavonoids and lignans and risk of bladder cancer and its main morphological type, urothelial cell carcinoma (UCC), within the European Prospective Investigation into Cancer and Nutrition (EPIC) study. METHODS: A cohort of 477 312 men and women mostly aged 35-70 years, were recruited in 10 European countries. At baseline, dietary flavonoid and lignan intakes were estimated using centre-specific validated questionnaires and a food composition database based on the Phenol-Explorer, the UK Food Standards Agency and the US Department of Agriculture databases. RESULTS: During an average of 11 years of follow-up, 1575 new cases of primary bladder cancer were identified, of which 1425 were UCC (classified into aggressive (n=430) and non-aggressive (n=413) UCC). No association was found between total flavonoid intake and bladder cancer risk. Among flavonoid subclasses, significant inverse associations with bladder cancer risk were found for intakes of flavonol (hazard ratio comparing fifth with first quintile (HRQ5-Q1) 0.74, 95% confidence interval (CI): 0.61-0.91; P-trend=0.009) and lignans (HRQ5-Q1 0.78, 95% CI: 0.62-0.96; P-trend=0.046). Similar results were observed for overall UCC and aggressive UCC, but not for non-aggressive UCC. CONCLUSIONS: Our study suggests an inverse association between the dietary intakes of flavonols and lignans and risk of bladder cancer, particularly aggressive UCC

    Spatio-Temporal Brain Mapping of Motion-Onset VEPs Combined with fMRI and Retinotopic Maps

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    Neuroimaging studies have identified several motion-sensitive visual areas in the human brain, but the time course of their activation cannot be measured with these techniques. In the present study, we combined electrophysiological and neuroimaging methods (including retinotopic brain mapping) to determine the spatio-temporal profile of motion-onset visual evoked potentials for slow and fast motion stimuli and to localize its neural generators. We found that cortical activity initiates in the primary visual area (V1) for slow stimuli, peaking 100 ms after the onset of motion. Subsequently, activity in the mid-temporal motion-sensitive areas, MT+, peaked at 120 ms, followed by peaks in activity in the more dorsal area, V3A, at 160 ms and the lateral occipital complex at 180 ms. Approximately 250 ms after stimulus onset, activity fast motion stimuli was predominant in area V6 along the parieto-occipital sulcus. Finally, at 350 ms (100 ms after the motion offset) brain activity was visible again in area V1. For fast motion stimuli, the spatio-temporal brain pattern was similar, except that the first activity was detected at 70 ms in area MT+. Comparing functional magnetic resonance data for slow vs. fast motion, we found signs of slow-fast motion stimulus topography along the posterior brain in at least three cortical regions (MT+, V3A and LOR)
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