481 resultados para ARE
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Background Glutamate is the principal excitatory neurotransmitter in the central nervous system which acts by the activation of either ionotropic (AMPA, NMDA and kainate receptors) or G-protein coupled metabotropic receptors. Glutamate is widely accepted to play a major role in the path physiology of migraine as implicated by data from animal and human studies. Genes involved in synthesis, metabolism and regulation of both glutamate and its receptors could be, therefore, considered as potential candidates for causing/predisposing to migraine when mutated. Methods The association of polymorphic variants of GRIA1-GRIA4 genes which encode for the four subunits (GluR1-GluR4) of the alpha-amino-3- hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) receptor for glutamate was tested in migraineurs with and without aura (MA and MO) and healthy controls. Results Two variants in the regulative regions of GRIA1 (rs2195450) and GRIA3 (rs3761555) genes resulted strongly associated with MA (P = 0.00002 and P = 0.0001, respectively), but not associated with MO, suggesting their role in cortical spreading depression. Whereas the rs548294 variant in GRIA1 gene showed association primarily with MO phenotype, supporting the hypothesis that MA and MO phenotypes could be genetically related. These variants modify binding sites for transcription factors altering the expression of GRIA1 and GRIA3 genes in different conditions. Conclusions This study represents the first genetic evidence of a link between glutamate receptors and migraine.
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Background Road crashes contribute to high injury rates in Indigenous population in Aust, NZ, Canada and USA Alcohol one of the leading risk factors for road crashes: 31.5% Indigenous drivers in remote areas over 0.05mg/100ml, compared to 7.4 percent of non-Indigenous counterparts 17.5% Indigenous drivers in regional areas over 0.05mg/100ml compared to 3.8 percent of non-Indigenous counterparts Indigenous peoples are overrepresented in alcohol-related fatality rates, with this group 40% more likely to be killed
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Interpreting the unexplained component of the gender wage gap as indicative of discrimination, the empirical literature to date has tended to ignore the potential impact wage discrimination may have on employment. Employment effects may arise if discrimination lowers the female offered wage and the labour supply curve is upward sloping. The empirical analysis employs the British Household Panel Study and finds evidence of both wage and associated employment effects.
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Numerous studies have reported associations between IGF-I and other extra cellular matrix (ECM) proteins, including fibronectin (FN), integrins, IGF-binding proteins (IGFBPs) and through IGFBPs, with vitronectin (VN). Nevertheless, the precise nature and mechanisms of these interactions are still being characterised. In this paper, we discuss transglutaminases (TGases) as a constituent of the ECM and provide evidence for the first time that IGF-I is a lysine (K)-donor substrate to TGases. When IGF-I was incubated with an alpha-2 plasmin inhibitor-derived Q peptide in the presence of tissue transglutaminase (TG2), an IGF-I:Q peptide cross-linked species was detected using Western immunoblotting and confirmed by mass spectrometry. Similar findings were observed in the presence of Factor XIIIa (FXIIIa) TGase. To identify the precise location of this K-donor TGase site/s on IGF-I, all the three IGF-I K-sites, individually and collectively (K27, K65 and K68), were substituted to arginine (R) using site-directed mutagenesis. Incubation of these K→R IGF-I analogues with Q peptide in the presence of TG2 or FXIIIa resulted in the absence of cross-linking in IGF-I analogues bearing arginine substitution at site 68. This established that K68 within the IGF-I D-domain was the principal K-donor site to TGases. We further annotated the functional significance of these K→R IGF-I analogues on IGF-I mediated actions. IGF-I analogues with K→R substitution within the D-domain at K65 and K68 hindered migration of MCF-7 breast carcinoma cells and correspondingly reduced PI3-K/AKT activation. Therefore, this study also provides first insights into a possible functional role of the previously uncharacterised IGF-I D-domain.
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Background Vitamin D has a range of biological effects including antiproliferative functions that are mediated through its receptors, encoded by the VDR gene. Objectives We investigated polymorphisms within the VDR gene for association with solar keratosis (SK), a biomarker for skin cancer, and examined interactions with skin phenotype. Methods Among participants of the community-based Nambour Skin Cancer Study, we genotyped 190 people with SKs and 190 without for ApaI, TaqI and FokI polymorphisms. Results We found a significant difference in genotype frequencies of the TaqI polymorphism between affected and unaffected populations (P = 0Æ008). The TT ⁄tt genotype group was associated with a twofold increase in odds of being affected by one or more SK. Individuals with fair skin and the TT ⁄tt genotype had about a sevenfold increase, whereas fair-skinned people with the Tt genotype had a fourfold increase in odds of being affected by SK. Individuals with the TT ⁄tt genotype who were prone to burn and not tan on acute sun exposure had about a sixfold increase in odds of SK. Fair-skinned people with VDR-Apa AA ⁄aa genotypes had about an eightfold increase in odds of being affected by SK compared with a fivefold increase in individuals with the Aa genotype and fair skin. Conclusions The trend for homozygote genotypes to increase the odds of SK suggests that intermediate VDR activity is important in protection or that the heterodimer formed by a heterozygous genotype may have an altered binding potential. Overall, these analyses indicate that VDR may be important in SK development.
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The T-box family transcription factor gene TBX20 acts in a conserved regulatory network, guiding heart formation and patterning in diverse species. Mouse Tbx20 is expressed in cardiac progenitor cells, differentiating cardiomyocytes, and developing valvular tissue, and its deletion or RNA interference-mediated knockdown is catastrophic for heart development. TBX20 interacts physically, functionally, and genetically with other cardiac transcription factors, including NKX2-5, GATA4, and TBX5, mutations of which cause congenital heart disease (CHD). Here, we report nonsense (Q195X) and missense (I152M) germline mutations within the T-box DNA-binding domain of human TBX20 that were associated with a family history of CHD and a complex spectrum of developmental anomalies, including defects in septation, chamber growth, and valvulogenesis. Biophysical characterization of wild-type and mutant proteins indicated how the missense mutation disrupts the structure and function of the TBX20 T-box. Dilated cardiomyopathy was a feature of the TBX20 mutant phenotype in humans and mice, suggesting that mutations in developmental transcription factors can provide a sensitized template for adult-onset heart disease. Our findings are the first to link TBX20 mutations to human pathology. They provide insights into how mutation of different genes in an interactive regulatory circuit lead to diverse clinical phenotypes, with implications for diagnosis, genetic screening, and patient follow-up.
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The Chemistry Discipline Network has recently completed two distinct mapping exercises. The first is a snapshot of chemistry taught at 12 institutions around Australia in 2011. There were many similarities but also important differences in the content taught and assessed at different institutions. There were also significant differences in delivery, particularly laboratory contact hours, as well as forms and weightings of assessment. The second mapping exercise mapped the chemistry degrees at three institutions to the Threshold Learning Outcomes for chemistry. Importantly, some of the TLOs were addressed by multiple units at all institutions, while others were not met, or were met at an introductory level only. The exercise also exposed some challenges in using the TLOs as currently written.
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We have identified a migraine locus on chromosome 19p13.3/2 using linkage and association analysis. We isolated 48 single-nucleotide polymorphisms within the locus, of which we genotyped 24 in a Caucasian population comprising 827 unrelated cases and 765 controls. Five single-nucleotide polymorphisms within the insulin receptor gene showed significant association with migraine. This association was independently replicated in a case-control population collected separately. We used experiments with insulin receptor RNA and protein to investigate functionality for the migraine-associated single-nucleotide polymorphisms. We suggest possible functions for the insulin receptor in migraine pathogenesis.
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IL-17 is believed to be important for protection against extracellular pathogens, where clearance is dependent on neutrophil recruitment and local activation of epithelial cell defences. However, the role of IL-17 in protection against intracellular pathogens such as Chlamydia is less clear. We have compared (i) the course of natural genital tract C. muridarum infection, (ii) the development of oviduct pathology and (iii) the development of vaccine-induced immunity against infection in wild type (WT) BALB/c and IL-17 knockout mice (IL-17-/-) to determine if IL-17-mediated immunity is implicated in the development of infection-induced pathology and/or protection. Both the magnitude and duration of genital infection was significantly reduced in IL-17-/- mice compared to BALB/c. Similarly, hydrosalpinx was also greatly reduced in IL-17-/- mice and this correlated with reduced neutrophil and macrophage infiltration of oviduct tissues. Matrix metalloproteinase (MMP) 9 and MMP2 were increased in WT oviducts compared to IL-17-/- animals at day 7 post-infection. In contrast, oviducts from IL-17-/- mice contained higher MMP9 and MMP2 at day 21. Infection also elicited higher levels of Chlamydia-neutralizing antibody in serum of IL-17-/- mice than WT mice. Following intranasal immunization with C. muridarum Major Outer Membrane Protein (MOMP) and cholera toxin plus CpG adjuvants, significantly higher levels of chlamydial MOMP-specific IgG and IgA were found in serum and vaginal washes of IL-17-/- mice. T cell proliferation and IFNγ production by splenocytes was greater in WT animals following in vitro re-stimulation, however vaccination was only effective at reducing infection in WT, not IL-17-/- mice. Intranasal or transcutaneous immunization protected WT but not IL-17-/- mice against hydrosalpinx development. Our data show that in the absence of IL-17, the severity of C. muridarum genital infection and associated oviduct pathology are significantly attenuated, however neither infection or pathology can be reduced further by vaccination protocols that effectively protect WT mice.
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Background & Aims: Peroxisome proliferator-activated receptor (PPAR) γ is a transcription factor, highly expressed in colonic epithelial cells, adipose tissue and macrophages, with an important role in the regulation of inflammatory pathways. The common PPARγ variants C161T and Pro12Ala have recently been associated with Ulcerative Colitis (UC) and an extensive UC phenotype respectively, in a Chinese population. PPARγ Pro12Ala variant homozygotes appear to be protected from the development of Crohn's disease (CD) in European Caucasians. Methods: A case-control study was performed for both variants (CD n=575, UC n=306, Controls n=360) using a polymerase chain reaction (PCR)-restriction fragment length polymorphism analysis in an Australian IBD cohort. A transmission disequilibrium test was also performed using CD trios for the PPARγ C161T variant. Genotype-phenotype analyses were also undertaken. Results: There was no significant difference in genotype distribution data or allele frequency between CD and UC patients and controls. There was no difference in allele transmission for the C161T variant. No significant relationship between the variants and disease location was observed. Conclusions: We were unable to replicate in a Caucasian cohort the recent association between PPARγ C161T and UC or between PPARγ Pro12Ala and an extensive UC phenotype in a Chinese population. There are significant ethnic differences in genetic susceptibility to IBD and its phenotypic expression.
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Facial cues of racial outgroup or anger mediate fear learning that is resistant to extinction. Whether this resistance is potentiated if fear is conditioned to angry, other race faces has not been established. Two groups of Caucasian participants were conditioned with two happy and two angry face conditional stimuli (CSs). During acquisition, one happy and one angry face were paired with an aversive unconditional stimulus whereas the second happy and angry faces were presented alone. CS face race (Caucasian, African American) was varied between groups. During habituation, electrodermal responses were larger to angry faces regardless of race and declined less to other race faces. Extinction was immediate for Caucasian happy faces, delayed for angry faces regardless of race, and slowest for happy racial outgroup faces. Combining the facial cues of other race and anger does not enhance resistance to extinction of fear.
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The purpose of this paper is to provide an evolutionary perspective of cloud computing (CC) by integrating two previously disparate literatures: CC and information technology outsourcing (ITO). We review the literature and develop a framework that highlights the demand for the CC service, benefits, risks, as well as risk mitigation strategies that are likely to influence the success of the service. CC success in organisations and as a technology overall is a function of (i) the outsourcing decision and supplier selection, (ii) contractual and relational governance, and (iii) industry standards and legal framework. Whereas CC clients have little control over standards and/or the legal framework, they are able to influence other factors to maximize the benefits while limiting the risks. This paper provides guidelines for (potential) cloud computing users with respect to the outsourcing decision, vendor selection, service-level-agreements, and other issues that need to be addressed when opting for CC services. We contribute to the literature by providing an evolutionary and holistic view of CC that draws on the extensive literature and theory of ITO. We conclude the paper with a number of research paths that future researchers can follow to advance the knowledge in this field.
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Much is known about pedestrian behaviour and crash risk in developed countries. In contrast, the literature on pedestrian crash risk in developing countries reveals wide gaps in knowledge and understanding, and a comprehensive assessment is lacking. In particular, pedestrian behaviour in developing countries is fundamentally different in comparison to developed countries, and is influenced by a variety of less well understood contributing factors, leading to difficulty in modelling and predicting pedestrian crash risk and in turn identifying effective safety countermeasures. This paper provides a comprehensive synthesis of the factors known to influence pedestrian crash risk in developing countries, then focuses on Ethiopia as a specific example. The paper identifies where critical gaps in knowledge exist regarding pedestrian crash risk and associated behaviour in developing countries--a set of knowledge gaps which collectively are significant. The paper concludes by articulating a critical research path moving forward, with the aim to achieve an improved understanding of developing country pedestrian crash risk, and an ultimate goal of identifying effective pedestrian safety countermeasures suited to the unique challenges faced by transport system managers in developing countries.
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Identifying outstanding performers or ‘stars’ is a critical component of managing talent. However, organizational effectiveness in this area is limited by the current lack of guidance about the behaviour and characteristics of stars. We address this gap by combining a conceptual analysis with an empirical study involving 174 managers. Conceptually we examine the alignment of managers’ perceptions of outstanding performance with the well established task and contextual performance model and find this framework accounts for a core element in managers’ judgments about outstanding performers. However, a second, more qualitative approach finds that other dimensions including being self-directed, and a willingness to lead are also important. Our findings are consistent with a long-term trend toward identifying work effectiveness with highly discretionary, psychological and behavioural elements, and we consider the implications of this for the study and management of high level, individual effectiveness.
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The formalin test is increasingly applied as a model of inflammatory pain using high formalin concentrations (5–15%). However, little is known about the effects of low formalin concentrations on related behavioural responses. To examine this, rat pups were subjected to various concentrations of formalin at four developmental stages: 7, 13, 22, and 82 days of age. At postnatal day (PND) 7, sex differences in flinching but not licking responses were observed with 0.5% formalin evoking higher flinching in males than in females. A dose response was evident in that 0.5% formalin also produced higher licking responses compared to 0.3% or 0.4% formalin. At PND 13, a concentration of 0.8% formalin evoked a biphasic response. At PND 22, a concentration of 1.1% evoked higher flinching and licking responses during the late phase (10–30 min) in both males and females. During the early phase (0–5 min), 1.1% evoked higher licking responses compared to 0.9% or 1% formalin. 1.1% formalin produced a biphasic response that was not evident with 0.9 or 1%. At PND 82, rats displayed a biphasic pattern in response to three formalin concentrations (1.25%, 1.75% and 2.25%) with the presence of an interphase for both 1.75% and 2.25% but not for 1.25%. These data suggest that low formalin concentrations induce fine-tuned responses that are not apparent with the high formalin concentration commonly used in the formalin test. These data also show that the developing nociceptive system is very sensitive to subtle changes in formalin concentrations.