866 resultados para attention deficit disorder and hyperactivity disorder (ADHD)


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Patients with Bipolar Disorder (BD) perform poorly on tasks of selective attention and inhibitory control. Although similar behavioural deficits have been noted in their relatives, it is yet unclear whether they reflect dysfunction in the same neural circuits. We used functional magnetic resonance imaging and the Stroop Colour Word Task to compare task related neural activity between 39 euthymic BD patients, 39 of their first-degree relatives (25 with no Axis I disorders and 14 with Major Depressive Disorder) and 48 healthy controls. Compared to controls, all individuals with familial predisposition to BD, irrespective of diagnosis, showed similar reductions in neural responsiveness in regions involved in selective attention within the posterior and inferior parietal lobules. In contrast, hypoactivation within fronto-striatal regions, implicated in inhibitory control, was observed only in BD patients and MDD relatives. Although striatal deficits were comparable between BD patients and their MDD relatives, right ventrolateral prefrontal dysfunction was uniquely associated with BD. Our findings suggest that while reduced parietal engagement relates to genetic risk, fronto-striatal dysfunction reflects processes underpinning disease expression for mood disorders. © 2011 Elsevier Inc.

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Objectives: The sex of an individual is known to modulate the clinical presentation of bipolar disorder (BD), but little is known as to whether there are significant sex-by-diagnosis interactions on the brain structural and functional correlates of BD. Methods: We conducted a literature review of magnetic resonance imaging (MRI) studies in BD, published between January 1990 and December 2010, reporting on the effects of sex and diagnosis. In the absence of any functional MRI (fMRI) studies, this review was supplemented by original data analyses focusing on sex-by-diagnosis interactions on patterns of brain activation obtained during tasks of working memory, incentive decision-making, and facial affect processing. Results: We found no support for a sex-by-diagnosis interaction in global gray or white matter volume. Evidence regarding regional volumetric measures is limited, but points to complex interactions between sex and diagnosis with developmental and temperamental factors within limbic and prefrontal regions. Sex-by-diagnosis interactions were noted in the pattern of activation within the basal ganglia during incentive decision-making and within ventral prefrontal regions during facial affect processing. Conclusions: Potential sex-by-diagnosis interactions influencing the brain structural and functional correlates of disease expression in BD have received limited attention. Our data suggest that the sex of an individual modulates structure and function within subcortical and cortical regions implicated in disease expression. © 2012 The Authors. Journal compilation © 2012 John Wiley & Sons A/S.

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Background: There is substantial evidence that cognitive deficits and brain structural abnormalities are present in patients with Bipolar Disorder (BD) and in their first-degree relatives. Previous studies have demonstrated associations between cognition and functional outcome in BD patients but have not examined the role of brain morphological changes. Similarly, the functional impact of either cognition or brain morphology in relatives remains unknown. Therefore we focused on delineating the relationship between psychosocial functioning, cognition and brain structure, in relation to disease expression and genetic risk for BD. Methods: Clinical, cognitive and brain structural measures were obtained from 41 euthymic BD patients and 50 of their unaffected first-degree relatives. Psychosocial function was evaluated using the General Assessment of Functioning (GAF) scale. We examined the relationship between level of functioning and general intellectual ability (IQ), memory, attention, executive functioning, symptomatology, illness course and total gray matter, white matter and cerebrospinal fluid volumes. Limitations: Cross-sectional design. Results: Multiple regression analyses revealed that IQ, total white matter volume and a predominantly depressive illness course were independently associated with functional outcome in BD patients, but not in their relatives, and accounted for a substantial proportion (53%) of the variance in patients' GAF scores. There were no significant domain-specific associations between cognition and outcome after consideration of IQ. Conclusions: Our results emphasise the role of IQ and white matter integrity in relation to outcome in BD and carry significant implications for treatment interventions. © 2010 Elsevier B.V.

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In this manuscript we briefly describe bipolar disorder (a depressive and manic mental disease), its classification, its effects on the patient, which sometimes include suicidal tendencies, and the drugs used for treatment. We also address the status quo with regard to diagnosis of bipolar disorder and recent advances in bioanalytical approaches for biomarker discovery. These approaches focus on blood samples (serum and plasma) and proteins as the main biomarker targets, and use various strategies for protein depletion. Strategies include use of commercially available kits or other homemade strategies and use of classical proteomics methods for protein identification based on bottom-up or top-down approaches, which used SELDI, ESI, or MALDI as sources for mass spectrometry, and up-to-date mass analyzers, for example Orbitrap. We also discuss some future objectives for treatment of this disorder and possible directions for the correct diagnosis of this still-unclear mental illness.

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The XX male syndrome - Testicular Disorder of Sexual Differentiation (DSD) is a rare condition characterized by a spectrum of clinical presentations, ranging from ambiguous to normal male genitalia. We report hormonal, molecular and cytogenetic evaluations of a boy presenting with this syndrome. Examination of the genitalia at age of 16 months, showed: penis of 3.5 cm, proximal hypospadia and scrotal testes. Pelvic ultrasound did not demonstrate Mullerian duct structures. Karyotype was 46,XX. Gonadotrophin stimulation test yielded insufficient testosterone production. Gonadal biopsy showed seminiferous tubules without evidence of Leydig cells. Molecular studies revealed that SRY and TSPY genes and also DYZ3 sequences were absent. In addition, the lack of deletions or duplications of SOX9, NR5A1, WNT4 and NROB1 regions was verified. The infant was heterozygous for all microsatellites at the 9p region, including DMRT1 gene, investigated. Only 10% of the patients are SRY-negative and usually they have ambiguous genitalia, as the aforementioned patient. The incomplete masculinization suggests gain of function mutation in one or more genes downstream to SRY gene.

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The Bell-Lavis model for liquid water is investigated through numerical simulations. The lattice-gas model on a triangular lattice presents orientational states and is known to present a highly bonded low density phase and a loosely bonded high density phase. We show that the model liquid-liquid transition is continuous, in contradiction with mean-field results on the Husimi cactus and from the cluster variational method. We define an order parameter which allows interpretation of the transition as an order-disorder transition of the bond network. Our results indicate that the order-disorder transition is in the Ising universality class. Previous proposal of an Ehrenfest second order transition is discarded. A detailed investigation of anomalous properties has also been undertaken. The line of density maxima in the HDL phase is stabilized by fluctuations, absent in the mean-field solution. (C) 2009 American Institute of Physics. [doi:10.1063/1.3253297]

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Nitrogen-doped carbon nanotubes can provide reactive sites on the porphyrin-like defects. It is well known that many porphyrins have transition-metal atoms, and we have explored transition-metal atoms bonded to those porphyrin-like defects inN-doped carbon nanotubes. The electronic structure and transport are analyzed by means of a combination of density functional theory and recursive Green's function methods. The results determined the heme B-like defect (an iron atom bonded to four nitrogens) is the most stable and has a higher polarization current for a single defect. With randomly positioned heme B defects in nanotubes a few hundred nanometers long, the polarization reaches near 100%, meaning they are effective spin filters. A disorder-induced magnetoresistance effect is also observed in those long nanotubes, and values as high as 20 000% are calculated with nonmagnectic eletrodes.

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We hypothesized that the processing of auditory information by the perisylvian polymicrogyric cortex may be different from the normal cortex. To characterize the auditory processing in bilateral perisylvian syndrome, we examined ten patients with perisylvian polymicrogyria (Group 1) and seven control children (Group 11). Group I was composed by four children with bilateral perisylvian polymicrogyria and six children with bilateral posterior perisylvian polymicrogyria. The evaluation included neurological and neuroimaging investigation, intellectual quotient and audiological assessment (audiometry and behavior auditory tests). The results revealed a statistically significant difference between the groups in the behavioral auditory tests, Such as, digits dichotic test, nonverbal dichotic test (specifically in right attention), and random gap detection/random gap detection expanded tests. Our data showed abnormalities in the auditory processing of children with perisylvian polymicrogyria, suggesting that perisylvian polymicrogyric cortex is functionally abnormal. We also found a correlation between the severity of our auditory findings and the extent of the cortical abnormality. (C) 2009 Elsevier B.V. All rights reserved.

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Background A relationship exists between mental disorder and offending behaviours but the nature and extent of the association remains in doubt. Method Those convicted in the higher courts of Victoria between 1993 and 1995 had their pyschiatric history explored by case linkage to a register listing virtually all contacts with the public psychiatric services. Results Prior psychiatric contact was found in 25% or offenders, but the personality disorder and substance misuse accounted for much of this relationship. Schizophrenia and affective disorders were also over-represented, particularly those with coexisting substance misuse. Conclusions The increased offending in schizophrenia and affective illness is modest and may often be mediated by coexisting substance misuse. The risk of a serious crime being committed by someone with a major mental illness is small and does not justify subjecting them, as a group, to either increased institutional containment or greater coercion.