120 research outputs found

    Metanephric adenoma of the kidney: an unusual diagnostic challenge

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    Although metanephric adenoma (MA) is a rare, benign neoplasm of epithelial cells, it is often difficult to distinguish this entity from other malignant neoplasms preoperatively. We report a case of a large renal mass for which preoperative diagnosis was indeterminate, with the differential diagnosis including Wilm’s tumor, MA, and papillary renal cell carcinoma (PRCC). Accurate postoperative differentiation of MA from PRCC is critical because adjuvant therapy is considered after surgical resection of PRCC tumors

    Face or building superiority in peripheral vision reversed by task requirements

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    Peripheral vision has been the topic of few studies compared with central vision. Nevertheless, given that visual information covers all the visual field and that relevant information can originate from highly eccentric positions, the understanding of peripheral vision abilities for object perception seems essential. The poorer resolution of peripheral vision would first suggest that objects requiring large-scale feature integration such as buildings would be better processed than objects requiring finer analysis such as faces. Nevertheless, task requirements also determine the information (coarse or fine) necessary for a given object to be processed. We therefore investigated how task and eccentricity modulate object processing in peripheral vision. Three experiments were carried out requiring finer or coarser information processing of faces and buildings presented in central and peripheral vision. Our results showed that buildings were better judged as identical or familiar in periphery whilst faces were better categorised. We conclude that this superiority for a given stimulus in peripheral vision results (a) from the available information, which depends on the decrease of resolution with eccentricity, and (b) from the useful information, which depends on both the task and the semantic category

    A Novel Gene Signature for Molecular Diagnosis of Human Prostate Cancer by RT-qPCR

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    Prostate cancer (CaP) is one of the most relevant causes of cancer death in Western Countries. Although detection of CaP at early curable stage is highly desirable, actual screening methods present limitations and new molecular approaches are needed. Gene expression analysis increases our knowledge about the biology of CaP and may render novel molecular tools, but the identification of accurate biomarkers for reliable molecular diagnosis is a real challenge. We describe here the diagnostic power of a novel 8-genes signature: ornithine decarboxylase (ODC), ornithine decarboxylase antizyme (OAZ), adenosylmethionine decarboxylase (AdoMetDC), spermidine/spermine N(1)-acetyltransferase (SSAT), histone H3 (H3), growth arrest specific gene (GAS1), glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and Clusterin (CLU) in tumour detection/classification of human CaP. METHODOLOGY/PRINCIPAL FINDINGS: The 8-gene signature was detected by retrotranscription real-time quantitative PCR (RT-qPCR) in frozen prostate surgical specimens obtained from 41 patients diagnosed with CaP and recommended to undergo radical prostatectomy (RP). No therapy was given to patients at any time before RP. The bio-bank used for the study consisted of 66 specimens: 44 were benign-CaP paired from the same patient. Thirty-five were classified as benign and 31 as CaP after final pathological examination. Only molecular data were used for classification of specimens. The Nearest Neighbour (NN) classifier was used in order to discriminate CaP from benign tissue. Validation of final results was obtained with 10-fold cross-validation procedure. CaP versus benign specimens were discriminated with (80+/-5)% accuracy, (81+/-6)% sensitivity and (78+/-7)% specificity. The method also correctly classified 71% of patients with Gleason score<7 versus > or =7, an important predictor of final outcome. CONCLUSIONS/SIGNIFICANCE: The method showed high sensitivity in a collection of specimens in which a significant portion of the total (13/31, equal to 42%) was considered CaP on the basis of having less than 15% of cancer cells. This result supports the notion of the "cancer field effect", in which transformed cells extend beyond morphologically evident tumour. The molecular diagnosis method here described is objective and less subjected to human error. Although further confirmations are needed, this method poses the potential to enhance conventional diagnosis

    Neuro-cognitive mechanisms of conscious and unconscious visual perception: From a plethora of phenomena to general principles

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    Psychological and neuroscience approaches have promoted much progress in elucidating the cognitive and neural mechanisms that underlie phenomenal visual awareness during the last decades. In this article, we provide an overview of the latest research investigating important phenomena in conscious and unconscious vision. We identify general principles to characterize conscious and unconscious visual perception, which may serve as important building blocks for a unified model to explain the plethora of findings. We argue that in particular the integration of principles from both conscious and unconscious vision is advantageous and provides critical constraints for developing adequate theoretical models. Based on the principles identified in our review, we outline essential components of a unified model of conscious and unconscious visual perception. We propose that awareness refers to consolidated visual representations, which are accessible to the entire brain and therefore globally available. However, visual awareness not only depends on consolidation within the visual system, but is additionally the result of a post-sensory gating process, which is mediated by higher-level cognitive control mechanisms. We further propose that amplification of visual representations by attentional sensitization is not exclusive to the domain of conscious perception, but also applies to visual stimuli, which remain unconscious. Conscious and unconscious processing modes are highly interdependent with influences in both directions. We therefore argue that exactly this interdependence renders a unified model of conscious and unconscious visual perception valuable. Computational modeling jointly with focused experimental research could lead to a better understanding of the plethora of empirical phenomena in consciousness research

    CMS physics technical design report : Addendum on high density QCD with heavy ions

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    Automatic object identification: an fMRI study.

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    Boucart and Humphreys reported an automatic access to object identity when observers attend to a physical property of the form of an object (e.g. the orientation) but not to its colour. We sought evidence for automatic identification in a brain imaging study using fMRI. In an orientation decision task participants decided whether a picture was vertical or horizontal. In the colour decision task participants decided if a picture was blue or green. Activation of areas 18-19 was found for both color and orientation. Activation of the temporal area 37 occurred more frequently in the orientation than in the colour decision task. This result suggests that automatic identification activates the same brain area as overt processing of semantic information

    Functional integration in schizophrenia: too little or too much? Preliminary results on fMRI data.

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    International audienceThe disconnectivity hypothesis proposes that schizophrenia results from poor or miswired anatomical connections. Theoretically, its functional counterpart should be disintegration. Integration is thought to allow segregated neurons to interact as a coherent whole, referred to as the "core", while the non-interacting part of the brain is referred to as the "rest". In this study, it is suggested that schizophrenia is the result of rest noise interfering with core activity. Two possible causes are assessed: (i) defective core integration, making the core more vulnerable to noise from the rest, or (ii) the rest being too highly integrated, meaning that it can interfere with the core. These hypotheses were tested using fMRI data acquired from 13 stabilized medicated schizophrenic subjects compared to 11 matched controls. Subjects were required to perform a series of lexical decision and retrieval tasks in separate sessions. The brain was divided into 90 components. Integration was defined as the amount of information shared between the components of a sub-system. An iterative aggregation procedure made it possible to identify a core on the basis of the functional clustering index, which assesses the integration of the core relative to its integration with the rest. Correlation of component-pairs within the core was also compared between the two groups. This procedure was repeated for each subject and for each task. Cores did not differ between the two groups, either in terms of integration or in terms of functional clustering index. However, the core was still highly integrated with the rest and the rest was overly integrated in schizophrenic subjects. Both anomalies were correlated with the negative symptoms. These findings were consistent regardless of the task considered. Furthermore, within the core, anterior-posterior correlations were lower in patients (between the frontal and the parietal and posterior cingulate cortices), whereas frontal left-right correlations were excessive. No significant correlation was found with the medication. Thus, it appears that schizophrenia entails a deleterious combination of too much "noisy" integration (from the rest) and too little "significant" integration (anterior-posterior functional connectivity)
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