104 resultados para Chromosomal disorders

em CentAUR: Central Archive University of Reading - UK


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There has been recent interest in the use of X-chromosomal loci for forensic and relatedness testing casework, with many authors developing new X-linked short tandem repeat (STR) loci suitable for forensic use. Here we present formulae for two key quantities in paternity testing, the average probability of exclusion and the paternity index, which are suitable for Xchromosomal loci in the presence of population substructure.

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The overall immunopathogenesis relevant to a large series of disorders caused by a drug or its associated hyperimmune condition is discussed based upon examining the genetics of severe drug-induced bullous skin problems (sporadic idiosyncratic adverse events including Stevens-Johnson syndrome and Toxic epidermal necrolysis). New results from an exemplar study on shared precipitating and perpetuating inner causes with other related disease phenotypes including aphtous stomatitis, Behcets, erythema multiforme, Hashimoto's thyroiditis, pemphigus, periodic fevers, Sweet's syndrome and drug-induced multisystem hypersensitivity are presented. A call for a collaborative, wider demographic profiling and deeper immunotyping in suggested future work is made.

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The overall immunopathogenesis relevant to a large series of disorders caused by a drug or its associated hyperimmune condition is discussed based upon the examination of the genetics of severe drug-induced bullous skin problems (sporadic idiosyncratic adverse events, including Stevens-Johnson syndrome and toxic epidermal necrolysis). An overarching pharmacogenetic schema is proposed. Immune cognition and early-effector processes are focused upon and a challenging synthesis around systems evolution is explained by a variety of projective analogies. Etiology, human leukocyte antigen-B, immune stability, clysiregulation, pharmacomimicry, viruses and an aggressive ethnically differentiated 'karmic' response are discussed.

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Homeobox genes encode DNA-binding proteins, many of which are implicated in the control of embryonic development. Evolutionarily, most homeobox genes fall into two related clades: the ANTP and the PRD classes. Some genes in ANTP class, notably Hox, ParaHox, and NK genes, have an intriguing arrangement into physical clusters. To investigate the evolutionary history of these gene clusters, we examined homeobox gene chromosomal locations in the cephalochordate amphioxus, Branchiostoma floridae. We deduce that 22 amphioxus ANTP class homeobox genes localize in just three chromosomes. One contains the Hox cluster plus AmphiEn, AmphiMnx, and AmphiDll. The ParaHox cluster resides in another chromosome, whereas a third chromosome contains the NK type homeobox genes, including AmphiMsx and ArnphiTlx. By comparative analysis we infer that clustering of ANTP class homeobox genes evolved just once, during a series of extensive cis-duplication events of genes early in animal evolution. A trans-duplication event occurred later to yield the Hox and ParaHox gene clusters on different chromosomes. The results obtained have implications for understanding the origin of homeobox gene clustering, the diversification of the ANTP class of homeobox genes, and the evolution of animal genomes.

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Wheat, although moderately tolerant to salt, can not be cultivated in many areas. However, in the triticeae tribe, some of the wild wheat relatives are highly tolerant, e.g. Thinopyrum bessarabicum, which grows on the sea shore. Eight primary hexaploid tritipyrum lines, amphiploids between Triticum durum and Thinopyrum bessarabicum have been produced which can set seed in at least 250 mM NaCl. These tritipyrums (2n=6x=42, AABBEbEb) due to reasons such as brittle rachis, continuous production of tillers, late maturity, tall stature and meiotic instability will not fulfill the requirements of a successful commercial salt tolerant crop. To overcome such problems the substituted tritipyrum, in which selected Eb chromosomes are replaced by D genome chromosomes of 6x wheat, was produced from 6x tritipyrum x 6x wheat hybrids (F1: 2n=6x=42, AABBDEb) followed by selfing and backcrossing with 6x tritipyrum. The fertile plants among the above progenies were screened by the genomic fluorescent in situ hybridization technique to identify their Eb and D chromosome constitution. This study showed that producing tritiprum with variable numbers of Eb and D genome chromosomes is feasible and that FISH is a useful technique for determining the number of Eb chromosomes present.

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Children with autistic spectrum disorders (ASDs) tend to suffer from severe gastrointestinal problems. Such symptoms may be due to a disruption of the indigenous gut flora promoting the overgrowth of potentially pathogenic micro-organisms. The faecal flora of patients with ASDs was studied and compared with those of two control groups (healthy siblings and unrelated healthy children). Faecal bacterial populations were assessed through the use of a culture-independent technique, fluorescence in situ hybridization, using oligonucleotide probes targeting predominant components of the gut flora. The faecal flora of ASD patients contained a higher incidence of the Clostridium histolyticum group (Clostridium clusters I and 11) of bacteria than that of healthy children. However, the non-autistic sibling group had an intermediate level of the C. histolyticum group, which was not significantly different from either of the other subject groups. Members of the C. histolyticum group are recognized toxin-producers and may contribute towards gut dysfunction, with their metabolic products also exerting systemic effects. Strategies to reduce clostridial population levels harboured by ASD patients or to improve their gut microflora profile through dietary modulation may help to alleviate gut disorders common in such patients.

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Bone metabolism involves a complex balance between the deposition of matrix and mineralization and resorption. There is now good evidence that dietary components and herbal products can influence these processes, particularly by inhibiting bone resorption, thus having beneficial effects on the skeleton. For example, it has been reported that a number of common vegetables, including onion, garlic and parsley, can inhibit bone resorption in ovariectomized rats. Essential oils derived from sage, rosemary, thyme and other herbs inhibit osteoclast activity in vitro and in vitro and leading to an increase in bone mineral density. Soya, a rich source of isoflavones, has shown promising results and epidemiological evidence to support a use in maintaining bone health, and various traditional herbal formulae in Chinese and Ayurvedic medicine also have demonstrable effects in pharmacological models of osteoporosis. Recently, cannabinoids have been described as having positive effects on osteoblast differentiation, and the presence of cannabinoid receptors in bone tissue indicates a more complex role in bone metabolism than previously thought. The first part of this review briefly discusses normal bone metabolism and disorders caused by its disruption, with particular reference to osteoporosis and current pharmacological treatments. The effects of natural products on bone and connective tissue are then discussed, to include items of diet, herbal extracts and food supplements, with evidence for their efficacy outlined. Copyright (c) 2006 John Wiley & Sons, Ltd.

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Objective: Autism spectrum disorders are now recognized to occur in up to 1% of the population and to be a major public health concern because of their early onset, lifelong persistence, and high levels of associated impairment. Little is known about the associated psychiatric disorders that may contribute to impairment. We identify the rates and type of psychiatric comorbidity associated with ASDs and explore the associations with variables identified as risk factors for child psychiatric disorders. Method: A subgroup of 112 ten- to 14-year old children from a population-derived cohort was assessed for other child psychiatric disorders (3 months' prevalence) through parent interview using the Child and Adolescent Psychiatric Assessment. DSM-IV diagnoses for childhood anxiety disorders, depressive disorders, oppositional defiant and conduct disorders, attention-deficit/hyperactivity disorder, tic disorders, trichotillomania, enuresis, and encopresis were identified. Results: Seventy percent of participants had at least one comorbid disorder and 41% had two or more. The most common diagnoses were social anxiety disorder (29.2%, 95% confidence interval [CI)] 13.2-45.1), attention-deficit/hyperactivity disorder (28.2%, 95% CI 13.3-43.0), and oppositional defiant disorder (28.1%, 95% CI 13.9-42.2). Of those with attention/deficit/hyperactivity disorder, 84% received a second comorbid diagnosis. There were few associations between putative risk factors and psychiatric disorder. Conclusions: Psychiatric disorders are common and frequently multiple in children with autism spectrum disorders. They may provide targets for intervention and should be routinely evaluated in the clinical assessment of this group.

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Objective: The aims of these studies were (a) to investigate the relationship between attentional bias and eating disorders and (b) examine the impact of psychological treatment on attentional bias. Method: The first study compared performance on a pictorial dot probe of 82 female patients with clinical eating disorders and 44 healthy female controls. The second study compared the performance of 31 patients with eating disorder on the same task before and after receiving 20 weeks of standardized cognitive behavior therapy. Twenty-four patients with eating disorder served as wait-list controls. Results: With the exception of neutral shape stimuli, attentional biases for eating, shape, and weight stimuli were greater in the patient sample than the healthy controls. The second study found that attentional biases significantly reduced after active treatment only. Conclusion: Attentional biases may be an expression of the eating disorder. The question of whether such biases warrant specific intervention requires further investigation. (C) 2008 by Wiley Periodicals, Inc.

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Objective: To examine the relationship between eating disorders and attentional biases. Method: The first study comprised 23 female patients with clinical eating disorders, women with high levels of anxiety (n = 19), and three female normal control groups comprising low (n = 31), moderate (n = 21), or high levels of shape concern (n 23). The second study comprised 82 women with clinical eating disorders and 44 healthy controls. All participants completed measures of eating disorder psychopathology and completed a modified pictorial dot-probe task. Results: In the first study, biases were found for negative eating and neutral weight pictures, and for positive eating pictures in women with eating disorders; these biases were greater than those found in anxious and normal controls. The second study replicated these findings and biases were also found for negative and neutral shape stimuli. Conclusion: It is concluded that future research should establish whether such biases warrant specific therapeutic interventions. (c) 2007 by Wiley Periodicals, Inc.

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Background Recent research provides evidence for specific disturbance in feeding and growth in children of mothers with eating disorders. Aim To investigate the impact of maternal eating disorders during the post-natal year on the internal world of children, as expressed in children's representations of self and their mother in pretend mealtime play at 5 years of age. Methods Children of mothers with eating disorders (n = 33) and a comparison group (n = 24) were videotaped enacting a family mealtime in pretend play. Specific classes of children's play representations were coded blind to group membership. Univariate analyses compared the groups on representations of mother and self. Logistic regression explored factors predicting pretend play representations. Results Positive representations of the mother expressed as feeding, eating or body shape themes were more frequent in the index group. There were no other significant group differences in representations. In a logistic regression analysis, current maternal eating psychopathology was the principal predictor of these positive maternal representations. Marital criticism was associated with negative representations of the mother. Conclusions These findings suggest that maternal eating disorders may influence the development of a child's internal world, such that they are more preoccupied with maternal eating concerns. However, more extensive research on larger samples is required to replicate these preliminary findings.

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We present an integrative review of the development of child anxiety, drawing on a number of strands of research. Family aggregation and genetic studies indicate raised vulnerability to anxiety in offspring of adults with the disorder (e.g. the temperamental style of behavioural inhibition, or information processing biases). Environmental factors are also important; these include adverse life events and exposure to negative information or modelling. Parents are likely to be key, although not unique, sources of such influences, particularly if they are anxious themselves. Some parenting behaviours associated with child anxiety, such as overprotection, may be elicited by child characteristics, especially in the context of parental anxiety, and these may serve to maintain child disorder. Emerging evidence emphasizes the importance of taking the nature of child and parental anxiety into account, of constructing assessments and interventions that are both disorder specific, and of considering bidirectional influences.

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This paper reviews recent theoretical, conceptual and practice developments in cognitive-behaviour therapy (CBT) for anxiety disorders. The empirical status of CBT for anxiety disorders is reviewed and recent advances in the field are outlined. Challenges for the future development of CBT for the anxiety disorders are examined in relation to the efficacy, effectiveness and cost-effectiveness of the approach. It is concluded that the major challenge currently facing CBT for anxiety disorders in the UK is how to meet the increased demand for provision whilst maintaining high levels of efficacy and effectiveness. It is suggested that the creation of an evidence base for the dissemination of CBT needs to become a priority for empirical investigation in order effectively to expand the provision of CBT for anxiety disorders.

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Objective: Previous research has indicated that temporal factors [specifically, the duration of interstimulus intervals (ISI) during a threat processing task] may influence the nature of processing biases exhibited in nonclinical populations with some degree of eating disorder psychopathology (Meyer et al., Int J Eat Disord, 27, 405-410, 2000). The current study aimed to test this hypothesis by investigating attentional biases for eating-disorder-relevant images and irrelevant visual images (animals) in patients with eating disorders (n = 23) and psychiatric (n = 19) and nonpsychiatric (n = 65) controls. Method: A dot probe task was modified from previous research (Shafran et al., Int Eat Disord, 40, 369-380, 2007), whereby an original ISI of 500 ms was increased to 2.000 ms. Results: Patients with an eating disorder continued to display a bias in the processing of weight stimuli. However, biases noted in previous research for shape and weight stimuli disappeared when the ISI duration was increased in this way. Conclusion: These findings highlight the importance of temporal factors in whether processing biases are displayed and may point to ways in which biases actually work in this population. However, further research is warranted. (C) 2008 by Wiley Periodicals, Inc.