528 research outputs found

    A reporter for amyloid precursor protein γ-secretase activity in Drosophila

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    A key event in the pathogenesis of Alzheimer's disease (AD) is the deposition of senile plaques consisting largely of a peptide known as β-amyloid (Aβ) that is derived from the amyloid precursor protein (APP). A proteolytic activity called γ-secretase cleaves APP in the transmembrane domain and is required for Aβ generation. Aberrant γ-secretase cleavage of APP underlies the majority of early onset, familial AD. γ-Secretase resides in a large multi-protein complex, of which Presenilin, Nicastrin, APH-1 and PEN-2 are four essential components. Thus, identifying components and pathways by which the γ-secretase activity is regulated is crucial to understanding the mechanisms underlying AD pathogenesis, and may provide new diagnostic tools and therapeutic targets. Here we describe the generation of Drosophila that act as living reporters of γ-secretase activity in the fly eye. In these reporter flies the size of the eye correlates with the level of endogenous γ-secretase activity, and is very sensitive to the levels of three genes required for APP γ-secretase activity, presenilin, nicastrin and aph-1. Thus, these flies provide a sensitized system with which to identify other components of the γ-secretase complex and regulators of its activity. We have used these flies to carry out a screen for mutations that suppress γ-secretase activity and have identified a small chromosomal region that contains a gene or genes whose products may promote γ-secretase activity

    A bayesian approach for NDT data fusion: The Saint Torcato Church case study

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    This paper presents a methodology based on the Bayesian data fusion techniques applied to non-destructive and destructive tests for the structural assessment of historical constructions. The aim of the methodology is to reduce the uncertainties of the parameter estimation. The Young's modulus of granite stones was chosen as an example for the present paper. The methodology considers several levels of uncertainty since the parameters of interest are considered random variables with random moments. A new concept of Trust Factor was introduced to affect the uncertainty related to each test results, translated by their standard deviation, depending on the higher or lower reliability of each test to predict a certain parameter.The authors would like to acknowledge the Fundação para a Ciência e Tecnologia, which supported this research work as a part of the Project “Improved and innovative techniques for the diagnosis and monitoring of historical masonry”, PTDC/ECM/104045/2008

    Are fetal growth impairment and preterm birth causally related to child attention problems and ADHD?:Evidence from a comparison between high-income and middle-income cohorts

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    Cross-cohort comparison is an established method for improving causal inference. This study compared 2 cohorts, 1 from a high-income country and another from a middle-income country, to (1) establish whether birth exposures may play a causal role in the development of childhood attention problems; and (2) identify whether confounding structures play a different role in parent-reported attention difficulties compared with attention deficit hyperactivity disorder (ADHD) diagnoses.Birth exposures included low birth weight (LBW), small-for-gestational age (SGA), small head circumference (HC) and preterm birth (PTB)). Outcomes of interest were attention difficulties (Strengths and Difficulties Questionnaire, SDQ) and ADHD (Development and Well-Being Assessment, DAWBA). Associations between exposures and outcomes were compared between 7-year-old children from the Avon Longitudinal Study of Parents and Children (ALSPAC) in the UK (N=6849) and the 2004 Pelotas cohort in Brazil (N=3509).For attention difficulties (SDQ), the pattern of association with birth exposures was similar between cohorts: following adjustment, attention difficulties were associated with SGA (OR=1.59, 95% CI 1.20 to 2.19) and small HC (OR=1.64, 95% CI 1.11 to 2.41) in ALSPAC and SGA (OR=1.35, 95% CI 1.04 to 1.75) in Pelotas. For ADHD, however, the pattern of association following adjustment differed markedly between cohorts. In ALSPAC, ADHD was associated with LBW (OR=2.29, 95% CI 1.09 to 4.80) and PTB (OR=2.33, 95% CI 1.23 to 4.42). In the Pelotas cohort, however, ADHD was associated with SGA (OR=1.69, 95% CI 1.02 to 2.82).The findings suggest that fetal growth impairment may play a causal role in the development of attention difficulties in childhood, as similar associations were identified across both cohorts. Confounding structures, however, appear to play a greater role in determining whether a child meets the full diagnostic criteria for ADHD

    Physico-chemical characterization of inclusion complex between hydroxymethylnitrofurazone and hydroxypropyl-beta-cyclodextrin

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    Hydroxymethylnitrofurazone (NFOH) is a prodrug that is active against Trypanosoma cruzi. It however presents low solubility and high toxicity. Hydroxypropyl-beta-cyclodextrin (HP-beta-CD) can be used as a drug-delivery system for NFOH modifying its physico-chemical properties. The aim of this work is to characterize the inclusion complex between NFOH and HP-beta-CD. The rate of NFOH release decreases after complexation and thermodynamic parameters from the solubility isotherm studies revealed that a stable complex is formed (deltaGº= 1.7 kJ/mol). This study focuses on the physico-chemical characterization of a drug-delivery formulation that comes out as a potentially new therapeutic option for Chagas disease treatment.FAPESPCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES

    Denying humanness to victims: How gang members justify violent behavior

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    The high prevalence of violent offending amongst gang-involved youth has been established in the literature. Yet the underlying psychological mechanisms that enable youth to engage in such acts of violence remain unclear. 189 young people were recruited from areas in London, UK, known for their gang activity. We found that gang members, in comparison to non-gang youth, described the groups they belong to as having recognized leaders, specific rules and codes, initiation rituals, and special clothing. Gang members were also more likely than non-gang youth to engage in violent behavior and endorse moral disengagement strategies (i.e., moral justification, euphemistic language, advantageous comparison, displacement of responsibility, attribution of blame, and dehumanization). Finally, we found that dehumanizing victims partially mediated the relationship between gang membership and violent behavior. These findings highlight the effects of groups at the individual level and an underlying psychological mechanism that explains, in part, how gang members engage in violence

    Evaluation of the type of silo associated or not with additives on the nutritional value, aerobic stability, and microbiology of pearl millet silage

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    Abstract The objective of this study was to evaluate the effect of the silo type with the use or not of additives on chemical composition, in vitro gas production, fermentative losses, aerobic stability, fermentative profile, and microbial population of the pearl millet silage. We used a randomized block design in a 2 × 3 factorial scheme, with two types of silos (plastic bags and PVC silos) and three additives ([CON] without additive; 50 g of ground corn [GC], and Lactobacillus plantarum and Propionibacterium acidipropionici, with five replicates per treatment. We evaluated the chemical analyses, in vitro gas production, losses, aerobic stability, pH, ammoniacal nitrogen, and microbial population of the silages. The use of GC in the ensiling process improved the chemical composition of the silages. The additives and the type of silo did not affect (p > 0.05) the gas production kinetics, ammoniacal nitrogen, and population of lactic acid bacteria and fungi. Thus, the use of ground corn improved the nutritional value of the pearl millet silage. In turn, the inoculant provided better aerobic stability for the pearl millet silage. The plastic bag silos without vacuum were not efficient in the ensiling process like the PVC silos, which resulted in low-quality silage

    Defining and unpacking the core concepts of pharmacology education

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    Pharmacology education currently lacks a research-based consensus on which core concepts all graduates should know and understand, as well as a valid and reliable means to assess core conceptual learning. The Core Concepts in Pharmacology Expert Group (CC-PEG) from Australia and New Zealand recently identified a set of core concepts of pharmacology education as a first step toward developing a concept inventory—a valid and reliable tool to assess learner attainment of concepts. In the current study, CC-PEG used established methodologies to define each concept and then unpack its key components. Expert working groups of three to seven educators were formed to unpack concepts within specific conceptual groupings: what the body does to the drug (pharmacokinetics); what the drug does to the body (pharmacodynamics); and system integration and modification of drug–response. First, a one-sentence definition was developed for each core concept. Next, sub-concepts were established for each core concept. These twenty core concepts, along with their respective definitions and sub-concepts, can provide pharmacology educators with a resource to guide the development of new curricula and the evaluation of existing curricula. The unpacking and articulation of these core concepts will also inform the development of a pharmacology concept inventory. We anticipate that these resources will advance further collaboration across the international pharmacology education community to improve curricula, teaching, assessment, and learning.Marina Santiago, Elizabeth A. Davis, Tina Hinton, Thomas A. Angelo, Alison Shield, Anna-Marie Babey, Barbara Kemp-Harper, Gregg Maynard, Hesham S. Al-Sallami, Ian F. Musgrave, Lynette B. Fernandes, Suong N. T. Ngo, Arthur Christopoulos, Paul J. Whit

    Transient receptor potential canonical 5 (TRPC5) protects against pain and vascular inflammation in arthritis and joint inflammation

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    Objective: Transient receptor potential canonical 5 (TRPC5) is functionally expressed on a range of cells including fibroblast-like synoviocytes, which play an important role in arthritis. A role for TRPC5 in inflammation has not been previously shown in vivo. We investigated the contribution of TRPC5 in arthritis. Methods: Male wild-type and TRPC5 knockout (KO) mice were used in a complete Freund’s adjuvant (CFA)-induced unilateral arthritis model, assessed over 14 days. Arthritis was determined by measurement of knee joint diameter, hindlimb weightbearing asymmetry and pain behaviour. Separate studies involved chronic pharmacological antagonism of TRPC5 channels. Synovium from human post-mortem control and inflammatory arthritis samples were investigated for TRPC5 gene expression. Results: At baseline, no differences were observed. CFA-induced arthritis resulted in increased synovitis in TRPC5 KO mice assessed by histology. Additionally, TRPC5 KO mice demonstrated reduced ipsilateral weightbearing and nociceptive thresholds (thermal and mechanical) following CFA-induced arthritis. This was associated with increased mRNA expression of inflammatory mediators in the ipsilateral synovium and increased concentration of cytokines in synovial lavage fluid. Chronic treatment with ML204, a TRPC5 antagonist, augmented weightbearing asymmetry, secondary hyperalgesia and cytokine concentrations in the synovial lavage fluid. Synovia from human inflammatory arthritis demonstrated a reduction in TRPC5 mRNA expression. Conclusions: Genetic deletion or pharmacological blockade of TRPC5 results in an enhancement in joint inflammation and hyperalgesia. Our results suggest that activation of TRPC5 may be associated with an endogenous anti-inflammatory/analgesic pathway in inflammatory joint conditions
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