953 resultados para Development disorders
Resumo:
Research with adult samples has identified a cognitive risk factor for the development of panic and other anxiety disorders in the concept of anxiety sensitivity. The research to date on anxiety sensitivity in children, using the Childhood Anxiety Sensitivity Index (CASI), suggests that the CASI may help to garner knowledge regarding the development of anxiety sensitivity and also help to understand the development of panic attacks, panic disorder and other anxiety disorders in youth. To examine the development of anxiety sensitivity and its relation to panic in youth, data were collected on 44 children in 1998 who were administered the CASI in 1991. Results indicated that children whose CASI scores increased from Time 1 to Time 2 were significantly more likely to report experiencing panic attacks than children whose CASI scores decreased from Time 1 to Time 2. Specifically, 64% (9/14) of children whose CASI scores increased from Time 1 to Time 2 reported having one or more panic attacks versus 36% (5/14) reported having none. Moreover, 72% (21/29) of children whose CASI scores decreased from Time 1 to Time 2 reported no panic attacks. These results suggest that childhood may be the time when anxiety sensitivity as a risk factor for panic and panic disorder is developing. Results are discussed in terms of their relevance for understanding the development of panic and the need for further research to determine the generalizability of these findings in larger samples of children followed over different time spans. ^
Resumo:
Neural Crest cells (NCC) constitute a unique embryonic cell population that arises between the prospective epidermis and the dorsal aspect of the neural tube of vertebrates. NCC migrate ventromedially and dorsolaterally throughout the developing embryo giving rise to the peripheral nervous system constituents and melanocytes that ultimately reside in the skin and hair follicles respectively. Mice and humans with mutations in the Endothelin receptor b (Ednrb) gene manifest strikingly similar phenotypes characterized by hypopigmentation, hearing loss and megacolon these are due to absence of melanocytes in the skin and inner ear and lack of enteric ganglia in the distal part of the gut, respectively. Piebald lethal mice and humans with Hirschsprung's disease or Waardenburg syndrome carry different mutations in the Ednrb gene. The major goals of this project were to determine whether the action of Ednrb in NCC is required prior to commitment of these cells to the melanocytic lineage and to investigate its potential participation in the actual process of commitment. In order to achieve these goals transgenic mice that express Ednrb under two different regulatory elements were created. The first, Dct-Ednrb, expresses Ednrb under the control of the DOPAchrome tautomerase (Dct) promoter to direct expression to already committed melanocyte precursors. The second, Nes-Ednrb, expresses Ednrb under the regulation of the human nestin gene second enhancer to direct expression to pre-migratory NCC. Crosses of the Dct-Ednrb mouse with piebald lethal showed that the transgene was capable of rescuing the hypopigmentation phenotype of the later. This result indicates that the action of Ednrb after NCC commit to the melanocytic lineage is sufficient for normal melanocyte development. The Dct-Ednrb was further crossed with two other hypopigmentation mutants that carry mutations in the transcription factors Sox10 and Pax3. The transgene rescued the phenotype of the Sox10 mutant only. This suggests that Ednrb interacts with Sox10 but not with Pax3 during melanocyte development. The Nes-Ednrb mice developed a hypopigmentation phenotype that was augmented when crossed with piebald lethal or lethal spotting (mutation in Edn3, the ligand for Ednrb) mice but was rescued by over expression of Edn3. These results suggest that alterations in Ednrb expression early in development affect melanocyte development. This study provides novel information necessary to better understand the early embryonic development of NCC, clarifies specific interactions between different melanogenic genes and, could eventually help in the implementation of therapies for human pigmentary genetic disorders. ^
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Phobic and anxiety disorders are one of the most common, if not the most common and debilitating psychopathological conditions found among children and adolescents. As a result, a treatment research literature has accumulated showing the efficacy of cognitive behavioral treatment (CBT) for reducing anxiety disorders in youth. This dissertation study compared a CBT with parent and child (i.e., PCBT) and child group CBT (i.e., GCBT). These two treatment approaches were compared due to the recognition that a child’s context has an effect on the development, course, and outcome of childhood psychopathology and functional status. The specific aims of this dissertation were to examine treatment specificity and mediation effects of parent and peer contextual variables. The sample consisted of 183 youth and their mothers. Research questions were analyzed using analysis of variance for treatment outcome, and structural equation modeling, accounting for clustering effects, for treatment specificity and mediation effects. Results indicated that both PCBT and GCBT produced positive treatment outcomes across all indices of change (i.e., clinically significant improvement, anxiety symptom reduction) and across all informants (i.e., youths and parents) with no significant differences between treatment conditions. Results also showed partial treatment specific effects of positive peer relationships in GCBT. PCBT also showed partial treatment specific effects of parental psychological control. Mediation effects were only observed in GCBT; positive peer interactions mediated treatment response. The results support the use CBT with parents and peers for treating childhood anxiety. The findings’ implications are further discussed in terms of the need to conduct further meditational treatment outcome designs in order to continue to advance theory and research in child and anxiety treatment.
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HIV-associated neurocognitive disorders (HAND) is characterized by development of cognitive, behavioral and motor abnormalities, and occur in approximately 50% of HIV infected individuals. Our current understanding of HAND emanates mainly from HIV-1 subtype B (clade B), which is prevalent in USA and Western countries. However very little information is available on neuropathogenesis of HIV-1 subtype C (clade C) that exists in Sub-Saharan Africa and Asia. Therefore, studies to identify specific neuropathogenic mechanisms associated with HAND are worth pursuing to dissect the mechanisms underlying this modulation and to prevent HAND particularly in clade B infection. In this study, we have investigated 84 key human synaptic plasticity genes differential expression profile in clade B and clade C infected primary human astrocytes by using RT2 Profile PCR Array human Synaptic Plasticity kit. Among these, 31 and 21 synaptic genes were significantly (≥3 fold) down-regulated and 5 genes were significantly (≥3 fold) up-regulated in clade B and clade C infected cells, respectively compared to the uninfected control astrocytes. In flow-cytometry analysis, down-regulation of postsynaptic density and dendrite spine morphology regulatory proteins (ARC, NMDAR1 and GRM1) was confirmed in both clade B and C infected primary human astrocytes and SK-N-MC neuroblastoma cells. Further, spine density and dendrite morphology changes by confocal microscopic analysis indicates significantly decreased spine density, loss of spines and decreased dendrite diameter, total dendrite and spine area in clade B infected SK-N-MC neuroblastoma cells compared to uninfected and clade C infected cells. We have also observed that, in clade B infected astrocytes, induction of apoptosis was significantly higher than in the clade C infected astrocytes. In conclusion, this study suggests that down-regulation of synaptic plasticity genes, decreased dendritic spine density and induction of apoptosis in astrocytes may contribute to the severe neuropathogenesis in clade B infection.
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This study investigated the effects of an explicit individualized phonemic awareness intervention administered by a speech-language pathologist to 4 prekindergarten children with phonological speech sound disorders. Research has demonstrated that children with moderate-severe expressive phonological disorders are at-risk for poor literacy development because they often concurrently exhibit weaknesses in the development of phonological awareness skills (Rvachew, Ohberg, Grawburg, & Heyding, 2003).^ The research design chosen for this study was a single subject multiple probe design across subjects. After stable baseline measures, the participants received explicit instruction in each of the three phases separately and sequentially. Dependent measures included same-day tests for Phase I (Phoneme Identity), Phase II (Phoneme Blending), and Phase III (Phoneme Segmentation), and generalization and maintenance tests for all three phases.^ All 4 participants made substantial progress in all three phases. These skills were maintained during weekly and biweekly maintenance measures. Generalization measures indicated that the participants demonstrated some increases in their mean total number of correct responses in Phase II and Phase III baseline while the participants were in Phase I intervention, and more substantial increases in Phase III baseline while the participants were in Phase II intervention. Increased generalization from Phases II to III could likely be explained due to the response similarities in those two skills (Cooper, Heron, & Heward, 2007).^ Based upon the findings of this study, speech-language pathologists should evaluate phonological awareness in the children in their caseloads prior to kindergarten entry, and should allocate time during speech therapy to enhance phonological awareness and letter knowledge to support the development of both skills concurrently. Also, classroom teachers should collaborate with speech-language pathologists to identify at-risk students in their classrooms and successfully implement evidence-based phonemic awareness instruction. Future research should repeat this study including larger groups of children, children with combined speech and language delays, children of different ages, and ESOL students.^
Resumo:
This study investigated the effects of an explicit individualized phonemic awareness intervention administered by a speech-language pathologist to 4 prekindergarten children with phonological speech sound disorders. Research has demonstrated that children with moderate-severe expressive phonological disorders are at-risk for poor literacy development because they often concurrently exhibit weaknesses in the development of phonological awareness skills (Rvachew, Ohberg, Grawburg, & Heyding, 2003). The research design chosen for this study was a single subject multiple probe design across subjects. After stable baseline measures, the participants received explicit instruction in each of the three phases separately and sequentially. Dependent measures included same-day tests for Phase I (Phoneme Identity), Phase II (Phoneme Blending), and Phase III (Phoneme Segmentation), and generalization and maintenance tests for all three phases. All 4 participants made substantial progress in all three phases. These skills were maintained during weekly and biweekly maintenance measures. Generalization measures indicated that the participants demonstrated some increases in their mean total number of correct responses in Phase II and Phase III baseline while the participants were in Phase I intervention, and more substantial increases in Phase III baseline while the participants were in Phase II intervention. Increased generalization from Phases II to III could likely be explained due to the response similarities in those two skills (Cooper, Heron, & Heward, 2007). Based upon the findings of this study, speech-language pathologists should evaluate phonological awareness in the children in their caseloads prior to kindergarten entry, and should allocate time during speech therapy to enhance phonological awareness and letter knowledge to support the development of both skills concurrently. Also, classroom teachers should collaborate with speech-language pathologists to identify at-risk students in their classrooms and successfully implement evidence-based phonemic awareness instruction. Future research should repeat this study including larger groups of children, children with combined speech and language delays, children of different ages, and ESOL students
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The purpose of the present study was to examine the origins of anxiety sensitivity (AS) by assessing youths' learning experiences in relation to their AS symptoms and anxiety symptoms. Participants were 33 youths between 7 to 13 years old (M = 9.39 years, SD = 2.01). Youths were assessed using a structured interview and self-report measures. Chi-square analyses revealed no statistically significant differences in the proportions of boys vs. girls, Hispanic vs. non-Hispanic, and married vs. non-married. Pearson correlation analyses revealed that youths' AS learning experiences were significantly related to youths' AS and to youths' anxiety symptoms scores. Partial correlations between youths' learning experiences associated with AS symptoms in relation to AS scores controlling for anxiety symptoms effects were statistically significant. Findings were consistent with theory and suggest that learning mechanisms may be involved in AS acquisition and maintenance. The findings' implications are discussed regarding possible learning experiences' role in the development of AS.
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Through the awareness-raising efforts of several high-profile current and former athletes, the issue of common mental disorders (CMD) in this population is gaining increasing attention from researchers and practitioners alike. Yet the prevalence is unclear and most likely, under-reported. Whilst the characteristics of the sporting environment may generate CMD within the athletic population, it also may exacerbate pre-existing conditions, and hence it is not surprising that sport psychology and sport science practitioners are anecdotally reporting increased incidences of athletes seeking support for CMDs. In a population where there are many barriers to reporting and seeking help for CMD, due in part to the culture of the high performance sporting environment, anecdotal reports suggest that those athletes asking for help are approaching personnel who they are most comfortable talking to. In some cases, this may be a sport scientist, the sport psychologist or sport psychology consultant. Among personnel in the sporting domain, there is a perception that the sport psychologist or sport psychology consultant is best placed to assist athletes seeking assistance for CMD. However, sport psychology as a profession is split by two competing philosophical perspectives; one of which suggests that sport psychologists should work exclusively with athletes on performance enhancement, and the other views the athlete more holistically and accepts that their welfare may directly impact on their performance. To add further complication, the development of the profession of sport psychology varies widely between countries, meaning that practice in this field is not always clearly defined. This article examines case studies that illustrate the blurred lines in applied sport psychology practice, highlighting challenges with the process of referral in the U.K. athletic population. The article concludes with suggestions for ensuring the field of applied sport psychology is continually evolving and reconfiguring to ensure that it continues to meet the demands of its clients.
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Nervous system disorders are associated with cognitive and motor deficits, and are responsible for the highest disability rates and global burden of disease. Their recovery paths are vulnerable and dependent on the effective combination of plastic brain tissue properties, with complex, lengthy and expensive neurorehabilitation programs. This work explores two lines of research, envisioning sustainable solutions to improve treatment of cognitive and motor deficits. Both projects were developed in parallel and shared a new sensible approach, where low-cost technologies were integrated with common clinical operative procedures. The aim was to achieve more intensive treatments under specialized monitoring, improve clinical decision-making and increase access to healthcare. The first project (articles I – III) concerned the development and evaluation of a web-based cognitive training platform (COGWEB), suitable for intensive use, either at home or at institutions, and across a wide spectrum of ages and diseases that impair cognitive functioning. It was tested for usability in a memory clinic setting and implemented in a collaborative network, comprising 41 centers and 60 professionals. An adherence and intensity study revealed a compliance of 82.8% at six months and an average of six hours/week of continued online cognitive training activities. The second project (articles IV – VI) was designed to create and validate an intelligent rehabilitation device to administer proprioceptive stimuli on the hemiparetic side of stroke patients while performing ambulatory movement characterization (SWORD). Targeted vibratory stimulation was found to be well tolerated and an automatic motor characterization system retrieved results comparable to the first items of the Wolf Motor Function Test. The global system was tested in a randomized placebo controlled trial to assess its impact on a common motor rehabilitation task in a relevant clinical environment (early post-stroke). The number of correct movements on a hand-to-mouth task was increased by an average of 7.2/minute while the probability to perform an error decreased from 1:3 to 1:9. Neurorehabilitation and neuroplasticity are shifting to more neuroscience driven approaches. Simultaneously, their final utility for patients and society is largely dependent on the development of more effective technologies that facilitate the dissemination of knowledge produced during the process. The results attained through this work represent a step forward in that direction. Their impact on the quality of rehabilitation services and public health is discussed according to clinical, technological and organizational perspectives. Such a process of thinking and oriented speculation has led to the debate of subsequent hypotheses, already being explored in novel research paths.
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In the current study, we have developed a magnetic resonance imaging-based method for non-invasive detection of complement activation in placenta and foetal brain in vivo in utero. Using this method, we found that anti-complement C3-targeted ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles bind within the inflamed placenta and foetal brain cortical tissue, causing a shortening of the T2* relaxation time. We used two mouse models of pregnancy complications: a mouse model of obstetrics antiphospholipid syndrome (APS) and a mouse model of preterm birth (PTB). We found that detection of C3 deposition in the placenta in the APS model was associated with placental insufficiency characterised by increased oxidative stress, decreased vascular endothelial growth factor and placental growth factor levels and intrauterine growth restriction. We also found that foetal brain C3 deposition was associated with cortical axonal cytoarchitecture disruption and increased neurodegeneration in the mouse model of APS and in the PTB model. In the APS model, foetuses that showed increased C3 in their brains additionally expressed anxiety-related behaviour after birth. Importantly, USPIO did not affect pregnancy outcomes and liver function in the mother and the offspring, suggesting that this method may be useful for detecting complement activation in vivo in utero and predicting placental insufficiency and abnormal foetal neurodevelopment that leads to neuropsychiatric disorders.
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Deficits in social communication and interaction have been identified as distinguishing impairments for individuals with an autism spectrum disorder (ASD). As a pivotal skill, the successful development of social communication and interaction in individuals with ASD is a lifelong objective. Point-of-view video modeling has the potential to address these deficits. This type of video involves filming the completion of a targeted skill or behavior from a first-person perspective. By presenting only what a person might see from his or her viewpoint, it has been identified to be more effective in limiting irrelevant stimuli by providing a clear frame of reference to facilitate imitation. The current study investigated the use of point-of-view video modeling in teaching social initiations (e.g., greetings). Using a multiple baseline across participants design, five kindergarten participants were taught social initiations using point-of-view video modeling and video priming. Immediately before and after viewing the entire point-of-view video model, the participants were evaluated on their social initiations with a trained, typically developing peer serving as a communication partner. Specifically, the social initiations involved participants’ abilities to shift their attention toward the peer who entered the classroom, maintain attention toward the peer, and engage in an appropriate social initiation (e.g., hi, hello). Both generalization and maintenance were tested. Overall, the data suggest point-of-view video modeling is an effective intervention for increasing social initiations in young students with ASD. However, retraining was necessary for acquisition of skills in the classroom environment. Generalization in novel environments and with a novel communication partner, and generalization to other social initiation skills was limited. Additionally, maintenance of gained social initiation skills only occurred in the intervention room. Despite the limitations of the study and variable results, there are a number of implications moving forward for both practitioners and future researchers examining point-of-view modeling and its potential impact on the social initiation skills of individuals with ASD.
Resumo:
Collagen VI (COLVI), a protein ubiquitously expressed in connective tissues, is crucial for structural integrity, cellular adhesion, migration and survival. Six different genes are recognized in mammalians, encoding six COLVI-chains that assemble as two ‘short’ (α1, α2) and one ‘long’ chain (theoretically any one of α3–6). In humans, defects in the most widely expressed heterotrimer (α123), due to mutations in the COL6A1-3 genes, cause a heterogeneous group of neuromuscular disorders, collectively termed COLVI-related muscle disorders. Little is known about the function(s) of the recently described α4-6 chains and no mutations have been detected yet. In this study, we characterized two novel COLVI long chains in zebrafish that are most homologous to the mammalian α4 chain; therefore, we named the corresponding genes col6a4a and col6a4b. These orthologues represent ancestors of the mammalian Col6a4-6 genes. By in situ hybridization and RT-qPCR, we unveiled a distinctive expression kinetics for col6a4b, compared with the other col6a genes. Using morpholino antisense oligonucleotides targeting col6a4a, col6a4b and col6a2, we modelled partial and complete COLVI deficiency, respectively. All morphant embryos presented altered muscle structure and impaired motility. While apoptosis was not drastically increased, autophagy induction was defective in all morphants. Furthermore, motoneuron axon growth was abnormal in these morphants. Importantly, some phenotypical differences emerged between col6a4a and col6a4b morphants, suggesting only partial functional redundancy. Overall, our results further confirm the importance of COLVI in zebrafish muscle development and may provide important clues for potential human phenotypes associated with deficiency of the recently described COLVI-chains.
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Spectrum Disorder (ASD), is a heterogeneous neurodevelopmental disorder with na estimated global prevalence rate of 17:10000, and a male to female ratio of 4:1. Patients with ASD presente language and communication difficulties and stereotyped behaviours. Comorbidity with other disorders, such as Intelectual Disability, Fragile-X syndrome (FXS) epilepsy and tuberous sclerosis frequently occurs. ASD presents amultifactorial etiopathology, and genetic factos alone are not suficiente to explain how the syndrome arises, with recente studies establishing ASD heritability at approximately 50%. Pre-, peri- and post-natal exposure to toxic environmental factos has been implicated in the development of ASD. Involvement of epigenetic regulatory mechanisms has been suggested, supported by the occurrence of autistic symptoms in patients with disorders aris ing from epigenetic mutations, such as FXS. A polygenic and epistatic model is a strong hypothesis to explain ASD. The main goal of this project is to identify specific exposure patterns to environmental toxicants in children diagnosed with ASD and integrate the results with genetic and epigenetic data.
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There is clear evidence that in typically developing children reasoning and sense-making are essential in all mathematical learning and understanding processes. In children with autism spectrum disorders (ASD), however, these become much more significant, considering their importance to successful independent living. This paper presents a preliminary proposal of a digital environment, specifically targeted to promote the development of mathematical reasoning in students with ASD. Given the diversity of ASD, the prototyping of this environment requires the study of dynamic adaptation processes and the development of activities adjusted to each user’s profile. We present the results obtained during the first phase of this ongoing research, describing a conceptual model of the proposed digital environment. Guidelines for future research are also discussed.
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