225 research outputs found

    No evidence for association between tau gene haplotypic variants and susceptibility to Creutzfeldt-Jakob disease

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    Contains fulltext : 52965.pdf ( ) (Open Access)BACKGROUND: A polymorphism at codon 129 of the prion protein gene (PRNP) is the only well-known genetic risk factor for Creutzfeldt-Jakob disease (CJD). However, there is increasing evidence that other loci outside the PRNP open reading frame might play a role in CJD aetiology as well. METHODS: We studied tau protein gene (MAPT) haplotypic variations in a population of sporadic and variant CJD patients. We tested 6 MAPT haplotype tagging SNPs (htSNPs) in a Dutch population-based sample of sporadic CJD (sCJD) patients and a cognitively normal control group of similar age distribution. We genotyped the same polymorphisms in two other sample groups of sCJD cases from Italy and the UK. In addition, we compared MAPT haplotypes between sCJD and variant CJD (vCJD) patients. RESULTS: Single locus and haplotype analyses did not detect any significant difference between sCJD cases and controls. When we compared MAPT haplotypes between sCJD and variant CJD (vCJD) patients, we found that two of them were represented differently (H1f: 8% in sCJD versus 2% in vCJD; H1j:1% in sCJD versus 7% in vCJD). However, these two haplotypes were rare in both groups of patients, and taking the small sample sizes into account, we cannot exclude that the differences are due to chance. None of the p-values remained statistically significant after applying a multiple testing correction. CONCLUSION: Our study shows no evidence for an association between MAPT gene variations and sCJD, and some weak evidence for an association to vCJD

    Role of MAPT mutations and haplotype in frontotemporal lobar degeneration in Northern Finland

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    <p>Abstract</p> <p>Background</p> <p>Frontotemporal lobar degeneration (FTLD) consists of a clinically and neuropathologically heterogeneous group of syndromes affecting the frontal and temporal lobes of the brain. Mutations in microtubule-associated protein tau (<it>MAPT</it>), progranulin (<it>PGRN</it>) and charged multi-vesicular body protein 2B (<it>CHMP2B</it>) are associated with familial forms of the disease. The prevalence of these mutations varies between populations. The H1 haplotype of <it>MAPT </it>has been found to be closely associated with tauopathies and with sporadic FTLD. Our aim was to investigate <it>MAPT </it>mutations and haplotype frequencies in a clinical series of patients with FTLD in Northern Finland.</p> <p>Methods</p> <p><it>MAPT </it>exons 1, 2 and 9–13 were sequenced in 59 patients with FTLD, and <it>MAPT </it>haplotypes were analysed in these patients, 122 patients with early onset Alzheimer's disease (eoAD) and 198 healthy controls.</p> <p>Results</p> <p>No pathogenic mutations were found. The H2 allele frequency was 11.0% (<it>P </it>= 0.028) in the FTLD patients, 9.8% (<it>P </it>= 0.029) in the eoAD patients and 5.3% in the controls. The H2 allele was especially clustered in patients with a positive family history (<it>P </it>= 0.011) but did not lower the age at onset of the disease. The ApoE4 allele frequency was significantly increased in the patients with eoAD and in those with FTLD.</p> <p>Conclusion</p> <p>We conclude that although pathogenic <it>MAPT </it>mutations are rare in Northern Finland, the <it>MAPT </it>H2 allele may be associated with increased risks of FTLD and eoAD in the Finnish population.</p

    A linkage study of candidate loci in familial Parkinson's Disease

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    BACKGROUND: Parkinson's disease is the second most common neurodegenerative disorder after Alzheimer's disease. Most cases are sporadic, however familial cases do exist. We examined 12 families with familial Parkinson's disease ascertained at the Movement Disorder clinic at the Oregon Health Sciences University for genetic linkage to a number of candidate loci. These loci have been implicated in familial Parkinson's disease or in syndromes with a clinical presentation that overlaps with parkinsonism, as well as potentially in the pathogenesis of the disease. METHODS: The examined loci were PARK3, Parkin, DRD (dopa-responsive dystonia), FET1 (familial essential tremor), BDNF (brain-derived neurotrophic factor), GDNF (glial cell line-derived neurotrophic factor), Ret, DAT1 (the dopamine transporter), Nurr1 and Synphilin-1. Linkage to the α-synuclein gene and the Frontotemporal dementia with parkinsonism locus on chromosome 17 had previously been excluded in the families included in this study. Using Fastlink, Genehunter and Simwalk both parametric and model-free non-parametric linkage analyses were performed. RESULTS: In the multipoint parametric linkage analysis lod scores were below -2 for all loci except FET1 and Synphilin-1 under an autosomal dominant model with incomplete penetrance. Using non-parametric linkage analysis there was no evidence for linkage, although linkage could not be excluded. A few families showed positive parametric and non-parametric lod scores indicating possible genetic heterogeneity between families, although these scores did not reach any degree of statistical significance. CONCLUSIONS: We conclude that in these families there was no evidence for linkage to any of the loci tested, although we were unable to exclude linkage with both parametric and non-parametric methods

    Increased Number of Cerebellar Granule Cells and Astrocytes in the Internal Granule Layer in Sheep Following Prenatal Intra-amniotic Injection of Lipopolysaccharide

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    Chorioamnionitis is an important problem in perinatology today, leading to brain injury and neurological handicaps. However, there are almost no data available regarding chorioamnionitis and a specific damage of the cerebellum. Therefore, this study aimed at determining if chorioamnionitis causes cerebellar morphological alterations. Chorioamnionitis was induced in sheep by the intra-amniotic injection of lipopolysaccharide (LPS) at a gestational age (GA) of 110 days. At a GA of 140 days, we assessed the mean total and layer-specific volume and the mean total granule cell (GCs) and Purkinje cell (PC) number in the cerebelli of LPS-exposed and control animals using high-precision design-based stereology. Astrogliosis was assessed in the gray and white matter (WM) using a glial fibrillary acidic protein staining combined with gray value image analysis. The present study showed an unchanged volume of the total cerebellum as well as the molecular layer, outer and inner granular cell layers (OGL and IGL, respectively), and WM. Interestingly, compared with controls, the LPS-exposed brains showed a statistically significant increase (+20.4%) in the mean total number of GCs, whereas the number of PCs did not show any difference between the two groups. In addition, LPS-exposed animals showed signs of astrogliosis specifically affecting the IGL. Intra-amniotic injection of LPS causes morphological changes in the cerebellum of fetal sheep still detectable at full-term birth. In this study, changes were restricted to the inner granule layer. These cerebellar changes might correspond to some of the motor or non-motor deficits seen in neonates from compromised pregnancies

    Systematic review of health economic evaluation studies developed in Brazil from 1980-2013

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    BackgroundBrazil has sought to use economic evaluation to support healthcare decision-making processes. While a number of health economic evaluations (HEEs) have been conducted, no study has systematically reviewed the quality of Brazilian HEE. The objective of this systematic review was to provide an overview regarding the state of HEE research and to evaluate the number, characteristics, and quality of reporting of published HEE studies conducted in a Brazilian setting.MethodsWe systematically searched electronic databases (MEDLINE, EMBASE, Latin American, and Caribbean Literature on Health Sciences Database, Scientific Electronic Library Online, NHS Economic Evaluation Database, health technology assessment Database, Bireme, and Biblioteca Virtual em Saúde Economia da Saúde); citation indexes (SCOPUS, Web of Science), and Sistema de Informação da Rede Brasileira de Avaliação de Tecnologia em Saúde. Partial and full HEEs published between 1980 and 2013 that referred to a Brazilian setting were considered for inclusion.ResultsIn total, 535 studies were included in the review, 36.8% of these were considered to be full HEE. The category of healthcare technologies more frequently assessed were procedures (34.8%) and drugs (28.8%) which main objective was treatment (72.1%). Forty-four percent of the studies reported their funding source and 36% reported a conflict of interest. Overall, the full HEE quality of reporting was satisfactory. But some items were generally poorly reported and significant improvement is required: (1) methods used to estimate healthcare resource use quantities and unit costs, (2) methods used to estimate utility values, (3) sources of funding, and (4) conflicts of interest.ConclusionA steady number of HEE have been published in Brazil since 1980. To improve their contribution to inform national healthcare policy efforts need to be made to enhance the quality of reporting of HEEs and promote improvements in the way HEEs are designed, implemented (i.e., using sound methods for HEEs) and reported

    Haloperidol differentially modulates prepulse inhibition and p50 suppression in healthy humans stratified for low and high gating levels

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    Schizophrenia patients exhibit deficits in sensory gating as indexed by reduced prepulse inhibition (PPI) and P50 suppression, which have been linked to psychotic symptom formation and cognitive deficits. Although recent evidence suggests that atypical antipsychotics might be superior over typical antipsychotics in reversing PPI and P50 suppression deficits not only in schizophrenia patients, but also in healthy volunteers exhibiting low levels of PPI, the impact of typical antipsychotics on these gating measures is less clear. To explore the impact of the dopamine D2-like receptor system on gating and cognition, the acute effects of haloperidol on PPI, P50 suppression, and cognition were assessed in 26 healthy male volunteers split into subgroups having low vs high PPI or P50 suppression levels using a placebo-controlled within-subject design. Haloperidol failed to increase PPI in subjects exhibiting low levels of PPI, but attenuated PPI in those subjects with high sensorimotor gating levels. Furthermore, haloperidol increased P50 suppression in subjects exhibiting low P50 gating and disrupted P50 suppression in individuals expressing high P50 gating levels. Independently of drug condition, high PPI levels were associated with superior strategy formation and execution times in a subset of cognitive tests. Moreover, haloperidol impaired spatial working memory performance and planning ability. These findings suggest that dopamine D2-like receptors are critically involved in the modulation of P50 suppression in healthy volunteers, and to a lesser extent also in PPI among subjects expressing high sensorimotor gating levels. Furthermore, the results suggest a relation between sensorimotor gating and working memory performance

    Gaia Data Release 1: Open cluster astrometry: Performance, limitations, and future prospects

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    Context. The first Gaia Data Release contains the Tycho-Gaia Astrometric Solution (TGAS). This is a subset of about 2 million stars for which, besides the position and photometry, the proper motion and parallax are calculated using Hipparcos and Tycho-2 positions in 1991.25 as prior information. Aims. We investigate the scientific potential and limitations of the TGAS component by means of the astrometric data for open clusters. Methods. Mean cluster parallax and proper motion values are derived taking into account the error correlations within the astrometric solutions for individual stars, an estimate of the internal velocity dispersion in the cluster, and, where relevant, the effects of the depth of the cluster along the line of sight. Internal consistency of the TGAS data is assessed. Results. Values given for standard uncertainties are still inaccurate and may lead to unrealistic unit-weight standard deviations of least squares solutions for cluster parameters. Reconstructed mean cluster parallax and proper motion values are generally in very good agreement with earlier Hipparcos-based determination, although the Gaia mean parallax for the Pleiades is a significant exception. We have no current explanation for that discrepancy. Most clusters are observed to extend to nearly 15 pc from the cluster centre, and it will be up to future Gaia releases to establish whether those potential cluster-member stars are still dynamically bound to the clusters. Conclusions. The Gaia DR1 provides the means to examine open clusters far beyond their more easily visible cores, and can provide membership assessments based on proper motions and parallaxes. A combined HR diagram shows the same features as observed before using the Hipparcos data, with clearly increased luminosities for older A and F dwarfs

    Computational Identification of Transcriptional Regulators in Human Endotoxemia

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    One of the great challenges in the post-genomic era is to decipher the underlying principles governing the dynamics of biological responses. As modulating gene expression levels is among the key regulatory responses of an organism to changes in its environment, identifying biologically relevant transcriptional regulators and their putative regulatory interactions with target genes is an essential step towards studying the complex dynamics of transcriptional regulation. We present an analysis that integrates various computational and biological aspects to explore the transcriptional regulation of systemic inflammatory responses through a human endotoxemia model. Given a high-dimensional transcriptional profiling dataset from human blood leukocytes, an elementary set of temporal dynamic responses which capture the essence of a pro-inflammatory phase, a counter-regulatory response and a dysregulation in leukocyte bioenergetics has been extracted. Upon identification of these expression patterns, fourteen inflammation-specific gene batteries that represent groups of hypothetically ‘coregulated’ genes are proposed. Subsequently, statistically significant cis-regulatory modules (CRMs) are identified and decomposed into a list of critical transcription factors (34) that are validated largely on primary literature. Finally, our analysis further allows for the construction of a dynamic representation of the temporal transcriptional regulatory program across the host, deciphering possible combinatorial interactions among factors under which they might be active. Although much remains to be explored, this study has computationally identified key transcription factors and proposed a putative time-dependent transcriptional regulatory program associated with critical transcriptional inflammatory responses. These results provide a solid foundation for future investigations to elucidate the underlying transcriptional regulatory mechanisms under the host inflammatory response. Also, the assumption that coexpressed genes that are functionally relevant are more likely to share some common transcriptional regulatory mechanism seems to be promising, making the proposed framework become essential in unravelling context-specific transcriptional regulatory interactions underlying diverse mammalian biological processes

    Evidence-based Kernels: Fundamental Units of Behavioral Influence

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    This paper describes evidence-based kernels, fundamental units of behavioral influence that appear to underlie effective prevention and treatment for children, adults, and families. A kernel is a behavior–influence procedure shown through experimental analysis to affect a specific behavior and that is indivisible in the sense that removing any of its components would render it inert. Existing evidence shows that a variety of kernels can influence behavior in context, and some evidence suggests that frequent use or sufficient use of some kernels may produce longer lasting behavioral shifts. The analysis of kernels could contribute to an empirically based theory of behavioral influence, augment existing prevention or treatment efforts, facilitate the dissemination of effective prevention and treatment practices, clarify the active ingredients in existing interventions, and contribute to efficiently developing interventions that are more effective. Kernels involve one or more of the following mechanisms of behavior influence: reinforcement, altering antecedents, changing verbal relational responding, or changing physiological states directly. The paper describes 52 of these kernels, and details practical, theoretical, and research implications, including calling for a national database of kernels that influence human behavior
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