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Search for a target object embedded in a visual scene involves the posterior parietal cortex. This region is thought to play a role in visual attention by counteracting the effects of distractors on targets or by inhibiting distractors. Using fMRI, we investigated whether the parietal cortex is also engaged in visual search without distractors. Cortical activation was compared between two 'single object' search tasks differing only in difficulty. Activation differences between both tasks were found in the anterior and inferior part of the intraparietal sulcus, but in neither its posterior part nor the frontal eye fields. Thus a subset of parietal regions participates in the control of visual search even in the absence of distractors.  相似文献   
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Background  

With the aim to simplify cancer management, cancer research lately dedicated itself more and more to discover and develop non-invasive biomarkers. In this connection, circulating cell-free DNA (ccf DNA) seems to be a promising candidate. Altered levels of ccf nuclear DNA (nDNA) and mitochondrial DNA (mtDNA) have been found in several cancer types and might have a diagnostic value.  相似文献   
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This study aimed to investigate the modulating effects of emotional context on pain perception in 16 patients with fibromyalgia syndrome (FMS) and 16 healthy control (HC) subjects. An infrared laser was used to apply individually adapted painful stimuli to the dorsum of the left hand. The emotional background of the painful stimuli was modulated by concurrent presentations of negative, neutral, and positive picture stimuli selected from the International Affective Picture System. As control conditions, painful stimuli and the pictures were also presented by themselves. During each of the 5 laser-picture trials, subjects received 10 painful stimuli and were asked to rate the average intensity and unpleasantness of the experienced pain. Functional magnetic resonance images were obtained, using a T2 sensitive echo planar sequence. HC subjects showed a linear increase in pain intensity and unpleasantness ratings when painful stimuli were presented during positive, neutral, and negative pictures. In contrast, FMS patients showed a quadratic trend for pain intensity ratings indicating a lack of pain reduction by the positive pictures. In addition, the FMS patients showed less activation in secondary somatosensory cortex, insula, orbitofrontal cortex, and anterior cingulate cortex during the positive picture pain trials. Our results suggest that fibromyalgia patients are less efficient in modulating pain by positive affect and may benefit less from appetitive events than healthy control subjects.  相似文献   
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OBJECTIVES: We examined the concentration of activin A in a prospective manner before the clinical manifestation of preeclampsia and compared the data with those of cell-free fetal DNA in the maternal plasma. METHODS: The levels of activin A were analysed by enzyme-linked immunosorbent assay (ELISA) for pregnant women: (1) with preeclampsia (n = 34) in the third-trimester and normal controls (n = 44); and (2) at-risk of preeclampsia in the second-trimester (n = 15) as indicated by uterine artery Doppler and normal controls (n = 68). Correlation between activin A level and cell-free fetal DNA level was examined using the Spearman rank test. RESULTS: The level of plasma activin A was significantly higher in the preeclamptic samples (12.056 vs 7.068 ng/mL, p = 0.000). The increase in the activin A concentration was observed prior to the onset of preeclampsia (3.483 vs 1.324 ng/mL, p = 0.000). This increase in activin A correlated significantly with the increased level of cell-free fetal DNA, in the maternal circulation prior to the onset of preeclampsia (r = 0.977, p = 0.000). CONCLUSION: Our data suggest that circulatory activin A could be an independent biomarker for the early identification and monitoring of preeclampsia.  相似文献   
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Fos-related antigen 1 (Fra-1) is a Fos family member overexpressed in several types of human cancers. Here, we report that Fra-1 is highly expressed in the muscle-invasive form of the carcinoma of the bladder (80%) and to a lesser extent in superficial bladder cancer (42%). We demonstrate that in this type of cancer Fra-1 is regulated via a C-terminal instability signal and C-terminal phosphorylation. We show that manipulation of Fra-1 expression levels in bladder cancer cell lines affects cell morphology, motility and proliferation. The gene coding for AXL tyrosine kinase is directly upregulated by Fra-1 in bladder cancer and in other cell lines. Importantly, our data demonstrate that AXL mediates the effect of Fra-1 on tumour cell motility but not on cell proliferation. We suggest that AXL may represent an attractive therapeutic target in cancers expressing high Fra-1 levels.  相似文献   
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Gonadal impairment is an important late effect with a significant impact on quality of life of transplanted patients. The aim of this study was to compare gonadal function after busulfan (Bu) or treosulfan (Treo) conditioning regimens in pre- and postpubertal children. This retrospective, multicenter study included children transplanted in pediatric European Society for Blood and Marrow Transplantation (EBMT) centers between 1992 and 2012 who did not receive gonadotoxic chemoradiotherapy before the transplant. We evaluated 137 patients transplanted in 25 pediatric EBMT centers. Median age at transplant was 11.04 years (range, 5 to 18); 89 patients were boys and 48 girls. Eighty-nine patients were prepubertal at transplant and 48 postpubertal. One hundred eighteen children received Bu and 19 Treo. A higher proportion of girls treated with Treo in the prepubertal stage reached spontaneous puberty compared with those treated with Bu (P = .02). Spontaneous menarche was more frequent after Treo than after Bu (P < .001). Postpubertal boys and girls treated with Treo had significantly lower luteinizing hormone levels (P = .03 and P = .04, respectively) compared with the Bu group. Frequency of gonadal damage associated with Treo was significantly lower than that observed after Bu. These results need to be confirmed in a larger population.  相似文献   
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According to a classical view of visual object recognition, targets are detected "pre-attentively" if they carry unique features, whereas attention has to be deployed serially to object locations for feature binding if the targets can be distinguished from distracters only in terms of their feature conjunctions. Consistent with this view, recent reports suggest a contribution of the posterior parietal cortex (PPC; one major region controlling spatial attention) to conjunction search as opposed to feature search. However, PPC engagement in conjunction search might also reflect feature-based attention or the difficulty of target selection. The present fMRI study compared regions and amplitudes of cortical activity reflecting the attention mechanisms of a conjunction and a feature search of equal difficulty performed during maintenance of fixation. Attention-related activity was assessed by comparing each hard feature and conjunction search with an easy feature search. Hard feature and conjunction search activated overlapping regions in multiple PPC areas and in the frontal eye field (FEF). Most consistent PPC overlaps were located in the anterior and posterior intraparietal sulcus (IPS). The response amplitude of posterior IPS did not differ between both search tasks. However, the IPS junction with the transverse occipital sulcus and the FEF responded at a higher amplitude during conjunction search. Moreover, regions of the prefrontal cortex and the PPC were activated only during either hard feature or conjunction search. These findings suggest that equally difficult visual searches for features and conjunctions are controlled by overlapping frontoparietal networks, but also that both search types involve specific mechanisms.  相似文献   
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