232 resultados para Methioninoxidation, Oxidativer Stress
Resumo:
Research in this thesis focussed on the improvement of agricultural crops in increasing water use efficiency that impacts global crop productivity. The study identified key genetic regulatory mechanisms that the resurrection plant Tripogon loliiformis utilises to tolerate desiccation. Due to the conserved nature of the pathways involved, this information can be transferred for the enhancement of drought tolerance and water use efficiency in agricultural crops. Specifically this study used high throughput sequencing, microscopy and plant transformation to further the understanding of post-transcriptional regulatory mechanisms. It was shown that T. loliiformis uses microRNAs to regulate pro-survival autophagy pathways to tolerate desiccation.
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Factors contributing to academic achievement among recently arrived Chinese adolescents in Australia remains relatively underexplored. Previous studies focused on Asian migrants, including Chinese, but did not distinguish Chinese from other Asian migrants. The current study specifically looks at Chinese migrants who have recently arrived as opposed to Asian migrants. This study aims to explore the role of social support, school belonging, and acculturative stress on academic achievement of recently arrived Chinese adolescents (n = 55). Questionnaires were administered to this sample. The results indicated that school belonging, interestingly, was negatively associated with academic achievement. Perceived social support and acculturative stress were not significantly associated with academic achievement. The findings provide insights into risk and protective factors influencing academic achievement of Chinese migrants. Implications of the findings are discussed.
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The mechanism by which human leukocyte antigen B27 (HLA-B27) contributes to ankylosing spondylitis (AS) remains unclear. Genetic studies demonstrate that association with and interaction between polymorphisms of endoplasmic reticulum aminopeptidase 1 (ERAP1) and HLA-B27 influence the risk of AS. It has been hypothesised that ERAP1-mediated HLA-B27 misfolding increases endoplasmic reticulum (ER) stress, driving an interleukin (IL) 23-dependent, pro-inflammatory immune response. We tested the hypothesis that AS-risk ERAP1 variants increase ER-stress and concomitant pro-inflammatory cytokine production in HLA-B27 + but not HLA-B27-AS patients or controls. Forty-nine AS cases and 22 healthy controls were grouped according to HLA-B27 status and AS-associated ERAP1 rs30187 genotypes: HLA-B27 + ERAP1 risk, HLA-B27 + ERAP1 protective, HLA-B27-ERAP1 risk and HLA-B27-ERAP1 protective. Expression levels of ER-stress markers GRP78 (8 kDa glucose-regulated protein), CHOP (C/EBP-homologous protein) and inflammatory cytokines were determined in peripheral blood mononuclear cell and ileal biopsies. We found no differences in ER-stress gene expression between HLA-B27 + and HLA-B27-cases or healthy controls, or between cases or controls stratified by carriage of ERAP1 risk or protective alleles in the presence or absence of HLA-B27. No differences were observed between expression of IL17A or TNF (tumour necrosis factor) in HLA-B27 + ERAP1 risk, HLA-B27 + ERAP1 protective and HLA-B27-ERAP1 protective cases. These data demonstrate that aberrant ERAP1 activity and HLA-B27 carriage does not alter ER-stress levels in AS, suggesting that ERAP1 and HLA-B27 may influence disease susceptibility through other mechanisms. © 2015 Macmillan Publishers Limited.
Resumo:
Introduction Single nucleotide polymorphisms in ERAP2 are strongly associated with ankylosing spondylitis (AS). One AS-associated single nucleotide polymorphism, rs2248374, causes a truncated ERAP2 protein that is degraded by nonsense-mediated decay. Approximately 25% of the populations of European ancestry are therefore natural ERAP2 knockouts. We investigated the effect of this associated variant on HLA class I allele presentation, surface heavy chains, endoplasmic reticulum (ER) stress markers and cytokine gene transcription in AS. Methods Patients with AS and healthy controls with either AA or GG homozygous status for rs2248374 were studied. Antibodies to CD14, CD19-ECD, HLA-A-B-C, Valpha7.2, CD161, anti-HC10 and anti-HLA-B27 were used to analyse peripheral blood mononuclear cells. Expression levels of ER stress markers (GRP78 and CHOP) and proinflammatory genes (tumour necrosis factor (TNF), IL6, IL17 and IL22) were assessed by qPCR. Results There was no significant difference in HLAclass I allele presentation or major histocompatibility class I heavy chains or ER stress markers GRP78 and CHOP or proinflammatory gene expression between genotypes for rs2248374 either between cases, between cases and controls, and between controls. Discussion Large differences were not seen in HLAB27 expression or cytokine levels between subjects with and without ERAP2 in AS cases and controls. This suggests that ERAP2 is more likely to influence AS risk through other mechanisms.
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Background Stress, craving, and depressed mood have all been implicated in alcohol use treatment lapses. Few studies have examined all 3 factors. Progress has been limited because of difficulties with craving assessment. The Alcohol Craving Experience Questionnaire (ACE) is a new measure of alcohol craving. It is both psychometrically sound and conceptually rigorous. This prospective study examines a stress–treatment response model that incorporates mediation by craving and moderation by depressed mood and pharmacotherapy. Methods Five hundred and thirty-nine consecutively treated alcohol-dependent patients voluntarily participated in an abstinence-based 12-week cognitive-behavioral therapy (CBT) program at a hospital alcohol and drug outpatient clinic. Measures of stress, craving, depressed mood, and alcohol dependence severity were administered prior to treatment. Treatment lapse and treatment dropout were assessed over the 12-week program duration. Results Patients reporting greater stress experienced stronger and more frequent cravings. Stronger alcohol craving predicted lapse, after controlling for dependence severity, stress, depression, and pharmacotherapy. Alcohol craving mediated stress to predict lapse. Depressed mood and anticraving medication were not significant moderators. Conclusions Among treatment seeking, alcohol-dependent patients, craving mediated the relationship between stress and lapse. The effect was not moderated by depressed mood or anticraving medication.
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Student participation in the classroom has long been regarded as an important means of increasing student engagement and enhancing learning outcomes by promoting active learning. However, the approach to class participation common in U.S. law schools, commonly referred to as the Socratic method, has been criticised for its negative impacts on student wellbeing. A multiplicity of American studies have identified that participating in law class discussions can be alienating, intimidating and stressful for some law students, and may be especially so for women, and students from minority backgrounds. Using data from the Law School Student Assessment Survey (LSSAS), conducted at UNSW Law School in 2012, this Chapter provides preliminary insights into whether assessable class participation (ACP) at an Australian law school is similarly alienating and stressful for students, including the groups identified in the American literature. In addition, we compare the responses of undergraduate Bachelor of Laws (LLB) and graduate Juris Doctor (JD) students. The LSSAS findings indicate that most respondents recognise the potential learning and social benefits associated with class participation in legal education, but remain divided over their willingness to participate. Further, in alignment with general trends identified in American studies, LLB students, women, international students, and non-native English speakers perceive they contribute less frequently to class discussions than JD students, males, domestic students, and native English speakers, respectively. Importantly, the LSSAS indicates students are more likely to be anxious about contributing to class discussions if they are LLB students (compared to their JD counterparts), and if English is not their first language (compared to native English speakers). There were no significant differences in students’ self-reported anxiety levels based on gender, which diverges from the findings of American research.
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While significant research has been undertaken exploring the pedagogical benefits of undertaking lengthy social work and human services field placements, there has been very little consideration regarding the potential financial stress involved for students. This study has addressed this knowledge gap. Research was conducted in 2014 using quantitative and qualitative methods with students, academic and professional staff from six Queensland Universities. The findings show a significant relationship between unpaid placements and financial hardship creating considerable stress for students and at times a compromised learning experience whilst on placement. The limited flexibility in the requirements of professional bodies and universities for how placements are undertaken has been identified as a key contributor to financial hardship. Addressing the complexities inherent in this issue requires a collaborative effort from multiple stakeholders and should not be regarded as a problem for students to endure and manage.