122 research outputs found

    Magnetic levitation on a type-I superconductor as a practical demonstration experiment for students

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    We describe and discuss an experimental set-up which allows undergraduate and graduate students to view and study magnetic levitation on a type-I superconductor. The demonstration can be repeated many times using one readily available 25 liter liquid helium dewar. We study the equilibrium position of a magnet that levitates over a lead bowl immersed in a liquid hand-held helium cryostat. We combine the measurement of the position of the magnet with simple analytical calculations. This provides a vivid visualization of magnetic levitation from the balance between pure flux expulsion and gravitation. The experiment contrasts and illustrates the case of magnetic levitation with high temperature type-II superconductors using liquid nitrogen, where levitation results from partial flux expulsion and vortex physics

    Group and sex differences in social cognition in bipolar disorder, schizophrenia/schizoaffective disorder and healthy people

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    Background: Impairment of social cognition is documented in bipolar disorder (BD) and schizophrenia/schizoaffective disorder (SCH). In healthy individuals, women perform better than men in some of its sub-domains. However, in BD and SCH the results are mixed. Our aim was to compare emotion recognition, affective Theory of Mind (ToM) and first- and second-order cognitive ToM in BD, SCH and healthy subjects, and to investigate sex-related differences. Methods: 120 patients (BD = 60, SCH = 60) and 40 healthy subjects were recruited. Emotion recognition was assessed by the Pictures of Facial Affect (POFA) test, affective ToM by the Reading the Mind in the Eyes Test (RMET) and cognitive ToM by several false-belief stories. Group and sex differences were analyzed using parametric (POFA, RMET) and non-parametric (false-belief stories) tests. The impact of age, intelligence quotient (IQ) and clinical variables on patient performance was examined using a series of linear/logistic regressions. Results: Both groups of patients performed worse than healthy subjects on POFA, RMET and second-order false-belief (p < 0.001), but no differences were found between them. Instead, their deficits were related to older age and/or lower IQ (p < 0.01). Subthreshold depression was associated with a 6-fold increased risk of first-order false-belief failure (p < 0.001). Sex differences were only found in healthy subjects, with women outperforming men on POFA and RMET (p ≤ 0.012), but not on first/second-order false-belief. Limitations: The cross-sectional design does not allow for causal inferences. Conclusion: BD and SCH patients had deficits in emotion recognition, affective ToM, and second-order cognitive ToM, but their performance was comparable to each other, highlighting that the differences between them may be subtler than previously thought. First-order cognitive ToM remained intact, but subthreshold depression altered their normal functioning. Our results suggest that the advantage of healthy women in the emotional and affective aspects of social cognition would not be maintained in BD and SCH

    Abnormal Distribution and Function of Circulating Monocytes and Enhanced Bacterial Translocation in Major Depressive Disorder

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    Introduction: Major depressive disorder (MDD) patients experience a systemic inflammatory stage. Monocytes play an important role in innate inflammatory responses and may be modulated by bacterial translocation. Our aim was to investigate the subset distribution and function of circulating monocytes, levels of proinflammatory cytokines, gut barrier damage, and bacterial translocation in MDD patients. Methods: Twenty-two MDD patients without concomitant diseases and 14 sex- and age-matched healthy controls were studied. The levels of circulating CD14++CD16- (classical), CD14++CD16++ (intermediate) and CD14- CD16++ (nonclassical) monocytes and the intracytoplasmic tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and IL-10 expression in the presence or absence of lipopolysaccharide (LPS) stimulation were analyzed by polychromatic flow cytometry. The serum TNF-α, IL-1β, IL-6, and IL-10 levels were measured by Luminex. LPS-binding protein (LBP), intestinal fatty acidbinding protein (I-FABP), and zonulin were measured by enzyme-linked immunosorbent assay (ELISA). Results: MDD patients had a significant increase in the frequency of intermediate monocytes and a significant decrease in the frequency of classical monocytes compared to those in the healthy controls. MDD patients had a significantly increased percentage of classical monocytes that expressed IL-1β, intermediate monocytes that expressed IL-1β and IL6 and nonclassical monocytes that expressed IL-1β, and decreased levels of nonclassical monocytes that expressed IL6 compared to those in the healthy controls. MDD patients had significantly increased levels of circulating TNF-α, IL-1β, LBP, and I-FABP compared to those in the healthy controls. MDD patients with high LBP levels had a significant reduction in the number of circulating monocytes compared to that in the normal-LBP MDD patients, which can be mainly ascribed to a decrease in the number of intermediate and nonclassical monocytes. Conclusions: We have demonstrated that compared to the healthy controls, MDD patients show a marked alteration in circulating monocytes, with an expansion of the intermediate subset with increased frequency of IL-1β and IL-6 producing cells. These patients also exhibited a systemic proinflammatory state, which was characterized by the enhanced serum TNF-α and IL-1β levels compared to those in the healthy controls. Furthermore, MDD patients showed increased LBP and I-FABP levels compared to those in healthy controls, indicating increased bacterial translocation and gut barrier damage

    Prognostic Role of 14F7 Mab Immunoreactivity against N-Glycolyl GM3 Ganglioside in Colon Cancer

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    Purpose. To assess the prognostic role of 14F7 Mab immunoreactivity, against N-Glycolyl GM3 ganglioside, in patients with colon cancer (CC) and to evaluate the relationship between its expression and clinicopathological features. Methods. Paraffin-embedded specimens were retrospectively collected from 50 patients with CC operated between 2004 and 2008. 14F7 Mab staining was determined by immunohistochemistry technique and its relation with survival and clinicopathologic features was evaluated. Results. The reactivity of 14F7 Mab was detected in all cases. Most cases had high level of immunostaining (70%) that showed statistical correlation with TNM stage (P=0.025). In univariate survival analysis, level of 14F7 Mab immunoreactivity (P=0.0078), TNM Stage (P=0.0007) and lymphovascular invasion (0.027) were significant prognostic factors for overall survival. Among these variables, level of 14F7 Mab immunoreactivity  (HR=0.268; 95%  CI  0.078–0.920; P=0.036) and TNM stage (HR=0.249; 95%  CI   0.066–0.932; P=0.039) were independent prognostic factors on multivariate analysis. Conclusions. This study is the first approach on the prognostic significance of 14F7 Mab immunoreactivity in patients with colon adenocarcinoma and this assessment might be used in the prognostic estimate of CC, although further studies will be required to validate these findings

    Mindfulness based cognitive therapy improves frontal control in bipolar disorder: a pilot EEG study

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    <p>Abstract</p> <p>Background</p> <p>Cognitive processing in Bipolar Disorder is characterized by a number of attentional abnormalities. Mindfulness Based Cognitive Therapy combines mindfulness meditation, a form of attentional training, along with aspects of cognitive therapy, and may improve attentional dysfunction in bipolar disorder patients.</p> <p>Methods</p> <p>12 euthymic BD patients and 9 control participants underwent record of electroencephalography (EEG, band frequency analysis) during resting states (eyes open, eyes closed) and during the completion of a continuous performance task (A-X version, EEG event-related potential (ERP) wave component analysis). The individuals with BD completed an 8-week MBCT intervention and record of EEG was repeated.</p> <p>Results</p> <p>(1) Brain activity, individuals with BD showed significantly decreased theta band power, increased beta band power, and decreased theta/beta ratios during the resting state, eyes closed, for frontal and cingulate cortices. Post MBCT intervention improvement over the right frontal cortex was seen in the individuals with BD, as beta band power decreased. (2) Brain activation, individuals with BD showed a significant P300-like wave form over the frontal cortex during the cue. Post MBCT intervention the P300-like waveform was significantly attenuated over the frontal cortex.</p> <p>Conclusions</p> <p>Individuals with BD show decreased attentional readiness and activation of non-relevant information processing during attentional processes. These data are the first that show, MBCT in BD improved attentional readiness, and attenuated activation of non-relevant information processing during attentional processes.</p

    What to consider when pseudohypoparathyroidism is ruled out: IPPSD and differential diagnosis

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    Background: Pseudohypoparathyroidism (PHP) is a rare disease whose phenotypic features are rather difficult to identify in some cases. Thus, although these patients may present with the Albright''s hereditary osteodystrophy (AHO) phenotype, which is characterized by small stature, obesity with a rounded face, subcutaneous ossifications, mental retardation and brachydactyly, its manifestations are somewhat variable. Indeed, some of them present with a complete phenotype, whereas others show only subtle manifestations. In addition, the features of the AHO phenotype are not specific to it and a similar phenotype is also commonly observed in other syndromes. Brachydactyly type E (BDE) is the most specific and objective feature of the AHO phenotype, and several genes have been associated with syndromic BDE in the past few years. Moreover, these syndromes have a skeletal and endocrinological phenotype that overlaps with AHO/PHP. In light of the above, we have developed an algorithm to aid in genetic testing of patients with clinical features of AHO but with no causative molecular defect at the GNAS locus. Starting with the feature of brachydactyly, this algorithm allows the differential diagnosis to be broadened and, with the addition of other clinical features, can guide genetic testing. Methods: We reviewed our series of patients (n = 23) with a clinical diagnosis of AHO and with brachydactyly type E or similar pattern, who were negative for GNAS anomalies, and classify them according to the diagnosis algorithm to finally propose and analyse the most probable gene(s) in each case. Results: A review of the clinical data for our series of patients, and subsequent analysis of the candidate gene(s), allowed detection of the underlying molecular defect in 12 out of 23 patients: five patients harboured a mutation in PRKAR1A, one in PDE4D, four in TRPS1 and two in PTHLH. Conclusions: This study confirmed that the screening of other genes implicated in syndromes with BDE and AHO or a similar phenotype is very helpful for establishing a correct genetic diagnosis for those patients who have been misdiagnosed with "AHO-like phenotype" with an unknown genetic cause, and also for better describing the characteristic and differential features of these less common syndromes

    Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases

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    The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular "reactive oxygen species" (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation. We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation). The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible. This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference
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