725 resultados para Autism Spectrum Disorders


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Much of the research on visual hallucinations (VHs) has been conducted in the context of eye disease and neurodegenerative conditions, but little is known about these phenomena in psychiatric and nonclinical populations. The purpose of this article is to bring together current knowledge regarding VHs in the psychosis phenotype and contrast this data with the literature drawn from neurodegenerative disorders and eye disease. The evidence challenges the traditional views that VHs are atypical or uncommon in psychosis. The weighted mean for VHs is 27% in schizophrenia, 15% in affective psychosis, and 7.3% in the general community. VHs are linked to a more severe psychopathological profile and less favorable outcome in psychosis and neurodegenerative conditions. VHs typically co-occur with auditory hallucinations, suggesting a common etiological cause. VHs in psychosis are also remarkably complex, negative in content, and are interpreted to have personal relevance. The cognitive mechanisms of VHs in psychosis have rarely been investigated, but existing studies point to source-monitoring deficits and distortions in top-down mechanisms, although evidence for visual processing deficits, which feature strongly in the organic literature, is lacking. Brain imaging studies point to the activation of visual cortex during hallucinations on a background of structural and connectivity changes within wider brain networks. The relationship between VHs in psychosis, eye disease, and neurodegeneration remains unclear, although the pattern of similarities and differences described in this review suggests that comparative studies may have potentially important clinical and theoretical implications.

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Much of the research on visual hallucinations (VHs) has been conducted in the context of eye disease and neurodegenerative conditions, but little is known about these phenomena in psychiatric and nonclinical populations. The purpose of this article is to bring together current knowledge regarding VHs in the psychosis phenotype and contrast this data with the literature drawn from neurodegenerative disorders and eye disease. The evidence challenges the traditional views that VHs are atypical or uncommon in psychosis. The weighted mean for VHs is 27% in schizophrenia, 15% in affective psychosis, and 7.3% in the general community. VHs are linked to a more severe psychopathological profile and less favorable outcome in psychosis and neurodegenerative conditions. VHs typically co-occur with auditory hallucinations, suggesting a common etiological cause. VHs in psychosis are also remarkably complex, negative in content, and are interpreted to have personal relevance. The cognitive mechanisms of VHs in psychosis have rarely been investigated, but existing studies point to source-monitoring deficits and distortions in top-down mechanisms, although evidence for visual processing deficits, which feature strongly in the organic literature, is lacking. Brain imaging studies point to the activation of visual cortex during hallucinations on a background of structural and connectivity changes within wider brain networks. The relationship between VHs in psychosis, eye disease, and neurodegeneration remains unclear, although the pattern of similarities and differences described in this review suggests that comparative studies may have potentially important clinical and theoretical implications. © 2014 The Author.

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Aim: Identify the incidence of vitreomacular traction (VMT) and frequency of reduced vision in the absence of other coexisting macular pathology using a pragmatic classification system for VMT in a population of patients referred to the hospital eye service. Methods: A detailed survey of consecutive optical coherence tomography (OCT) scans was done in a high-throughput ocular imaging service to ascertain cases of vitreomacular adhesion (VMA) and VMT using a departmental classification system. Analysis was done on the stages of traction, visual acuity, and association with other macular conditions. Results: In total, 4384 OCT scan episodes of 2223 patients were performed. Two hundred and fourteen eyes had VMA/VMT, with 112 eyes having coexisting macular pathology. Of 102 patients without coexisting pathology, 57 patients had VMT grade between 2 and 8, with a negative correlation between VMT grade and number of Snellen lines (r= -0.61717). There was a distinct cutoff in visual function when VMT grade was higher than 4 with the presence of cysts and sub retinal separation and breaks in the retinal layers. Conclusions: VMT is a common encounter often associated with other coexisting macular pathology. We estimated an incidence rate of 0.01% of VMT cases with reduced vision and without coexisting macular pathology that may potentially benefit from intervention. Grading of VMT to select eyes with cyst formation as well as hole formation may be useful for targeting patients who are at higher risk of visual loss from VMT.

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Polymyositis (PM) is usually associated to other autoimmune or connective tissue diseases. The authors report the case of a 59-year-old man with pulmonary fibrosis, who presented with constitutional symptoms and gradually developed proximal muscle weakness, Raynaud phenomenon, and dysphagia. Besides creatine kinase (CK) elevation, he had positive anti-Polymyositis-Scleromyositis (PM-Scl) and anti-Sjögren's-syndrome A (SSA) antibodies. Nailfold capillaroscopy showed a scleroderma pattern and muscle biopsy revealed necrosis, regeneration of muscle fibers, and inflammatory infiltrate. Prednisolone was started, with great improvement. Taking into account the overlap features between PM and systemic sclerosis sine scleroderma, it is important to closely monitor the patient for signs of pulmonary and cardiac decompensation.

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Objectives: To report on the design, significance and potential impacts of the first documented human clinical trial assessing the anxiolytic and thymoleptic efficacy of an aqueous monoextract of Piper methysticum (kava). The significance of the qualitative element of our clinical trial is also explored. The Kava Anxiety Depression Spectrum Study (KADSS) is a 3-week placebocontrolled, double-blind, cross-over trial involving 60 adult participants (18—65) with elevated stable anxiety and varying levels of depressive symptoms. Aims: The aims of KADSS are: (1) to determine whether an aqueous standardised extract of kava is effective for the treatment of anxiety; (2) to assess the effects of kava on differing levels of depression; and (3) to explore participants’ experience of taking kava via qualitative research. The study also provides preliminary assessment of the safety of an aqueous extract of kava in humans. Conclusion: If results reveal that the aqueous kava preparation exerts significant anxiolytic effects and appears safe, potentially beneficial impacts may occur. Data supporting a safe and effective kava extract may encourage a re-introduction of kava to Europe, UK and Canada. This may provide a major socioeconomic benefit to Pacific Island nations, and to sufferers of anxiety disorders.

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Recent findings from the clinic and the laboratory have transformed the way proteases and their inhibitors are perceived in the outermost layer of the skin, the epidermis. It now appears that an integrated proteolytic network operates within the epidermis, comprising more than 30 enzymes that carry out a growing list of essential functions. Equally, defective regulation or execution of protease-mediated processes is emerging as a key contributor to diverse human skin pathologies, and in recent years the number of diseases attributable to aberrant proteolytic activity has more than doubled. Here, we survey the different roles of proteases in epidermal homeostasis (from processing enzymes to signalling molecules) and explore the spectrum of rare and common human skin disorders where proteolytic pathways are dysregulated.

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Autism and Asperger syndrome (AS) are neurodevelopmental disorders characterised by deficient social and communication skills, as well as restricted, repetitive patterns of behaviour. The language development in individuals with autism is significantly delayed and deficient, whereas in individuals with AS, the structural aspects of language develop quite normally. Both groups, however, have semantic-pragmatic language deficits. The present thesis investigated auditory processing in individuals with autism and AS. In particular, the discrimination of and orienting to speech and non-speech sounds was studied, as well as the abstraction of invariant sound features from speech-sound input. Altogether five studies were conducted with auditory event-related brain potentials (ERP); two studies also included a behavioural sound-identification task. In three studies, the subjects were children with autism, in one study children with AS, and in one study adults with AS. In children with autism, even the early stages of sound encoding were deficient. In addition, these children had altered sound-discrimination processes characterised by enhanced spectral but deficient temporal discrimination. The enhanced pitch discrimination may partly explain the auditory hypersensitivity common in autism, and it may compromise the filtering of relevant auditory information from irrelevant information. Indeed, it was found that when sound discrimination required abstracting invariant features from varying input, children with autism maintained their superiority in pitch processing, but lost it in vowel processing. Finally, involuntary orienting to sound changes was deficient in children with autism in particular with respect to speech sounds. This finding is in agreement with previous studies on autism suggesting deficits in orienting to socially relevant stimuli. In contrast to children with autism, the early stages of sound encoding were fairly unimpaired in children with AS. However, sound discrimination and orienting were rather similarly altered in these children as in those with autism, suggesting correspondences in the auditory phenotype in these two disorders which belong to the same continuum. Unlike children with AS, adults with AS showed enhanced processing of duration changes, suggesting developmental changes in auditory processing in this disorder.

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Attention deficit hyperactivity disorder (ADHD) and autism are two neurodevelopmental disorders associated with prominent executive dysfunction, which may be underpinned by disruption within fronto-striatal and fronto-parietal circuits. We probed executive function in these disorders using a sustained attention task with a validated brain-behaviour basis. Twenty-three children with ADHD, 21 children with high-functioning autism (HFA) and 18 control children were tested on the Sustained Attention to Response Task (SART). In a fixed sequence version of the task, children were required to withhold their response to a predictably occurring no-go target (3) in a 1-9 digit sequence; in the random version the sequence was unpredictable. The ADHD group showed clear deficits in response inhibition and sustained attention, through higher errors of commission and omission on both SART versions. The HFA group showed no sustained attention deficits, through a normal number of omission errors on both SART versions. The HFA group showed dissociation in response inhibition performance, as indexed by commission errors. On the Fixed SART, a normal number of errors was made, however when the stimuli were randomised, the HFA group made as many commission errors as the ADHD group. Greater slow-frequency variability in response time and a slowing in mean response time by the ADHD group suggested impaired arousal processes. The ADHD group showed greater fast-frequency variability in response time, indicative of impaired top-down control, relative to the HFA and control groups. These data imply involvement of fronto-parietal attentional networks and sub-cortical arousal systems in the pathology of ADHD and prefromal cortex dysfunction in children with HFA. (c) 2007 Elsevier Ltd. All rights reserved.

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The conjunction fallacy has been cited as a classic example of the automatic contextualisation of problems. In two experiments we compared the performance of autistic and typically developing adolescents on a set of conjunction fallacy tasks. Participants with autism were less susceptible to the conjunction fallacy. Experiment 2 also demonstrated that the difference between the groups did not result from increased sensitivity to the conjunction rule, or from impaired processing of social materials amongst the autistic participants. Although adolescents with autism showed less bias in their reasoning they were not more logical than the control group in a normative sense. The findings are discussed in the light of accounts which emphasise differences in contextual processing between typical and autistic populations.

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Applied behaviour analysis (ABA)-based programmes are endorsed as the gold standard for treatment of children with autistic spectrum disorder (ASD) in most of North America. This is not the case in most of Europe, where instead a non-specified 'eclectic' approach is adopted. We explored the social validity of ABA-based interventions with 15 European families who had experience with home-based, mainly self-managed, ABA-based programmes for their own child/ren with ASD. The results of the study highlighted the overwhelmingly positive impact that ABA-based interventions had on their children in areas such as social skills, challenging behaviour, communication, gross and fine motor skills, concentration, interaction, independence, overall quality of life and, most importantly, a feeling of hope for the future. Implications for European policy on ASD are discussed. © 2013 NASEN.

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Prader-Willi syndrome (PWS) and Fragile X syndrome (FraX) are associated with distinctive cognitive and behavioural profiles. We examined whether repetitive behaviours in the two syndromes were associated with deficits in specific executive functions. PWS, FraX, and typically developing (TD) children were assessed for executive functioning using the Test of Everyday Attention for Children and an adapted Simon spatial interference task. Relative to the TD children, children with PWS and FraX showed greater costs of attention switching on the Simon task, but after controlling for intellectual ability, these switching deficits were only significant in the PWS group. Children with PWS and FraX also showed significantly increased preference for routine and differing profiles of other specific types of repetitive behaviours. A measure of switch cost from the Simon task was positively correlated to scores on preference for routine questionnaire items and was strongly associated with scores on other items relating to a preference for predictability. It is proposed that a deficit in attention switching is a component of the endophenotypes of both PWS and FraX and is associated with specific behaviours. This proposal is discussed in the context of neurocognitive pathways between genes and behaviour.

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This paper will explore from a ‘child’s rights perspective’ the ‘right’ of children with autistic spectrum disorder (ASD) to appropriate and meaningful education.Human ‘rights’ principles within international law will be evaluated in relation to how they have been interpreted and applied in relation to achieving this ‘right’. The International Convention of the Rights of the Child (United Nations in Convention on the rights of the child, office of the high commissioner, United Nations, Geneva, 1989) and the convention on the rights of the person with disability (United Nations in Convention on the rights of person’s with disabilities and optional protocol, office of the high commissioner, United Nations, Geneva, 2006) amongst others will be utilised to argue the case for ‘inclusive’educational opportunities to be a ‘right’ of every child on the autistic spectrum. The efficacy of mainstream inclusion is explored, identifying the position that a ‘one size fits all’model of education is not appropriate for all children with ASD.

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Chapter 1 introduces the scope of the work by identifying the clinically relevant prenatal disorders and presently available diagnostic methods. The methodology followed in this work is presented, along with a brief account of the principles of the analytical and statistical tools employed. A thorough description of the state of the art of metabolomics in prenatal research concludes the chapter, highlighting the merit of this novel strategy to identify robust disease biomarkers. The scarce use of maternal and newborn urine in previous reports enlightens the relevance of this work. Chapter 2 presents a description of all the experimental details involved in the work performed, comprising sampling, sample collection and preparation issues, data acquisition protocols and data analysis procedures. The proton Nuclear Magnetic Resonance (NMR) characterization of maternal urine composition in healthy pregnancies is presented in Chapter 3. The urinary metabolic profile characteristic of each pregnancy trimester was defined and a 21-metabolite signature found descriptive of the metabolic adaptations occurring throughout pregnancy. 8 metabolites were found, for the first time to our knowledge, to vary in connection to pregnancy, while known metabolic effects were confirmed. This chapter includes a study of the effects of non-fasting (used in this work) as a possible confounder. Chapter 4 describes the metabolomic study of 2nd trimester maternal urine for the diagnosis of fetal disorders and prediction of later-developing complications. This was achieved by applying a novel variable selection method developed in the context of this work. It was found that fetal malformations (FM) (and, specifically those of the central nervous system, CNS) and chromosomal disorders (CD) (and, specifically, trisomy 21, T21) are accompanied by changes in energy, amino acids, lipids and nucleotides metabolic pathways, with CD causing a further deregulation in sugars metabolism, urea cycle and/or creatinine biosynthesis. Multivariate analysis models´ validation revealed classification rates (CR) of 84% for FM (87%, CNS) and 85% for CD (94%, T21). For later-diagnosed preterm delivery (PTD), preeclampsia (PE) and intrauterine growth restriction (IUGR), it is found that urinary NMR profiles have early predictive value, with CRs ranging from 84% for PTD (11-20 gestational weeks, g.w., prior to diagnosis), 94% for PE (18-24 g.w. pre-diagnosis) and 94% for IUGR (2-22 g.w. pre-diagnosis). This chapter includes results obtained for an ultraperformance liquid chromatography-mass spectrometry (UPLC-MS) study of pre-PTD samples and correlation with NMR data. One possible marker was detected, although its identification was not possible. Chapter 5 relates to the NMR metabolomic study of gestational diabetes mellitus (GDM), establishing a potentially predictive urinary metabolic profile for GDM, 2-21 g.w. prior to diagnosis (CR 83%). Furthermore, the NMR spectrum was shown to carry information on individual phenotypes, able to predict future insulin treatment requirement (CR 94%). Chapter 6 describes results that demonstrate the impact of delivery mode (CR 88%) and gender (CR 76%) on newborn urinary profile. It was also found that newborn prematurity, respiratory depression, large for gestational age growth and malformations induce relevant metabolic perturbations (CR 82-92%), as well as maternal conditions, namely GDM (CR 82%) and maternal psychiatric disorders (CR 91%). Finally, the main conclusions of this thesis are presented in Chapter 7, highlighting the value of maternal or newborn urine metabolomics for pregnancy monitoring and disease prediction, towards the development of new early and non-invasive diagnostic methods.

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Mitochondria are central organelles for cell survival with particular relevance in energy production and signalling, being mitochondrial fatty acid β–oxidation (FAO) one of the metabolic pathways harboured in this organelle. FAO disorders (FAOD) are among the most well studied inborn errors of metabolism, mainly due to their impact in health. Nevertheless, some questions remain unsolved, as their prevalence in certain European regions and how pathophysiological determinants combine towards the phenotype. Analysis of data from newborn screening programs from Portugal and Spain allowed the estimation of the birth prevalence of FAOD revealing that this group of disorders presents in Iberia (and particularly in Portugal) one of the highest European birth prevalence, mainly due to the high birth prevalence of medium chain acyl-CoA dehydrogenase deficiency. These results highlight the impact of this group of genetic disorders in this European region. The characterization of mitochondrial proteome, from patients fibroblasts with FAOD, namely multiple acyl-CoA dehydrogenase deficiency (MADD) and long chain acyl-CoA dehydrogenase deficiency (LCHADD), provided a global perspective of the mitochondrial proteome plasticity in these disorders and highlights the main molecular pathways involved in their pathogenesis. Severe MADD forms show an overexpression of chaperones, antioxidant enzymes (MnSOD), and apoptotic proteins. An overexpression of glycolytic enzymes, which reflects cellular adaptation to energy deficiency due to FAO blockage, was also observed. When LCHADD fibroblasts were analysed a metabolic switching to glycolysis was also observed with overexpression of apoptotic proteins and modulation of the antioxidant defence system. Severe LCHADD present increased ROS alongside with up regulation of MnSOD while moderate forms have lower ROS and down-regulation of MnSOD. This probably reflects the role of MnSOD in buffering cellular ROS, maintain them at levels that allow cells to avoid damage and start a cellular response towards survival. When ROS levels are very high cells have to overexpress MnSOD for detoxifying proposes. When severe forms of MADD were compared to moderate forms no major differences were noticed, most probably because ROS levels in moderate MADD are high enough to trigger a response similar to that observed in severe forms. Our data highlights, for the first time, the differences in the modulation of antioxidant defence among FAOD spectrum. Overall, the data reveals the main pathways modulated in FAOD and the importance of ROS levels and antioxidant defence system modulation for disease severity. These results highlight the complex interaction between phenotypic determinants in FAOD that include genetic, epigenetic and environmental factors. The development of future better treatment approaches is dependent on the knowledge on how all these determinants interact towards phenotype.!

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Once thought to be rare, pervasive developmental disorders (PDDs) are now recognized as the most common neurological disorders affecting children and one of the most common developmental disabilities (DD) in Canada (Autism Society of Canada, 2006). Recent reports indicate that PDDs currently affect 1 in 150 children (Centre for Disease Control and Prevention, 2007). The purpose of this research was to provide an understanding of medical resident and practicing physicians' basic knowledge regarding PDDs. With a population of children with PDDs who present with varying symptoms, the ability for medical professionals to provide general information, diagnosis, appropriate referrals, and medical care can be quite complex. A basic knowledge of the disorder is only a first step in providing adequate medical care to individuals with autism and their families. An updated version of Stone's (1987) Autism survey was administered to medical residents at four medical schools in Canada and currently practicing physicians at three medical schools and one community health network. As well, a group of professionals specializing in the field ofPDDs, participating in research and clinical practice, were surveyed as an 'expert' group to act as a control measure. Expert responses were consistent with current research in the field. General findings indicated few differences in overall knowledge between residents and physicians, with misconceptions evident in areas such as the nature of the disorder, qualitative characteristics of autism, and effective interventions. Results were also examined by specialty and, while pediatricians demonstrated additional accurate 11 knowledge regarding the nature of the disorder and select qualitative impairments, both residents and practicing physicians demonstrated misconceptions about PDDs. This preliminary study replicated the findings of Stone (1987) and Heidgerken (2005) concerning several misconceptions of PDDs held by residents and practicing physicians. Future research should focus on additional replications with validated measures as well as the gathering of qualitative information, in order to inform the medical profession of the need for education in PDDs at training and professional levels.