Beschreibung: Background: In mammalian genetics, many quantitative traits, such as blood pressure, are thought to be influenced by specific genes, but are also affected by environmental factors, making the associated genes difficult to identify and locate from genetic data alone. In particular, the application of classical statistical methods to single nucleotide polymorphism (SNP) data collected in genome-wide association studies has been especially challenging. We propose a coalescent approach to search for SNPs associated with quantitative traits in genome-wide association study (GWAS) data by taking into account the evolutionary history among SNPs. Results: We evaluate the performance of the new method using simulated data, and find that it performs at least as well as existing methods with an increase in performance in the case of population structure. Application of the methodology to a real data set consisting of high-density lipoprotein cholesterol measurements in mice shows the method performs well for empirical data, as well. Conclusions: By combining methods from stochastic processes and phylogenetics, this work provides an innovative avenue for the development of new statistical methodology in the analysis of GWAS data.

Beschreibung: IntroductionEpithelial-to-mesenchymal transition (EMT) promotes cell migration and is important in metastasis. Cellular proliferation is often downregulated during EMT and the reverse transition (MET) in metastases appears to be required for restoration of proliferation in secondary tumors. We studied the interplay between EMT and proliferation control by MYB in breast cancer cells. Methods: MYB, ZEB1 and CDH1 expression levels were manipulated by lentiviral small hairpin RNA (shRNA)-mediated knockdown/overexpression, and verified by Western blotting, immunocytochemistry and qRT-PCR. Proliferation was assessed by bromodeoxyuridine pulse labeling and flow cytometry, and sulforhodamine B assays. EMT was induced with epidermal growth factor for 9 days or by exposure to hypoxia (1% oxygen) for up to 5 days, and assessed by qRT-PCR, cell morphology and colony morphology. Protein expression in human breast cancers was assessed by immunohistochemistry. ZEB1-MYB promoter binding and repression were determined by Chromatin Immunoprecipitation Assay and a luciferase reporter assay, respectively. Student's paired T tests, Mann--Whitney and repeated measures 2-way ANOVA tests determined statistical significance (P 〈 0.05). Results: Parental PMC42-ET cells displayed higher expression of ZEB1 and lower expression of MYB than the PMC42-LA epithelial variant. Knockdown of ZEB1 in PMC42-ET and MDA-MB-231 cells caused increased expression of MYB and a transition to a more epithelial phenotype, which in PMC42-ET cells was coupled with increased proliferation. Indeed, we observed an inverse relationship between MYB and ZEB1 expression in two in vitro EMT cell models, in matched human breast tumors and lymph node metastases, and in human breast cancer cell lines. Knockdown of MYB in PMC42-LA cells (MYBsh-LA) led to morphological changes and protein expression consistent with an EMT. ZEB1 expression was raised in MYBsh-LA cells and significantly repressed in MYB over-expressing MDA-MB-231 cells, which also showed reduced random migration and a shift from mesenchymal to epithelial colony morphology in two dimensional monolayer cultures. Finally, we detected binding of ZEB1 to MYB promoter in PMC42-ET cells, and ZEB1 over-expression repressed MYB promoter activity. Conclusions: This work identifies ZEB1 as a transcriptional repressor of MYB and suggests a reciprocal MYB-ZEB1 repressive relationship, providing a mechanism through which proliferation and the epithelial phenotype may be coordinately modulated in breast cancer cells.

Beschreibung: Background: Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder, which may result from alteration of the gastrointestinal microbiota following gastrointestinal infection, or with intestinal dysbiosis or small intestinal bacterial overgrowth. This may be treated with antibiotics, but there is concern that widespread antibiotic use might lead to antibiotic resistance. Some herbal medicines have been shown to be beneficial, but their mechanism(s) of action remain incompletely understood. To try to understand whether antibacterial properties might be involved in the efficacy of these herbal medicines, and to investigate potential new treatments for IBS, we have conducted a preliminary study in vitro to compare the antibacterial activity of the essential oils of culinary and medicinal herbs against the bacterium, Esherichia coli. Methods: Essential oils were tested for their ability to inhibit E. coli growth in disc diffusion assays and in liquid culture, and to kill E. coli in a zone of clearance assay. Extracts of coriander, lemon balm and spearmint leaves were tested for their antibacterial activity in the disc diffusion assay. Disc diffusion and zone of clearance assays were analysed by two-tailed t tests whereas ANOVA was performed for the turbidometric assays. Results: Most of the oils exhibited antibacterial activity in all three assays, however peppermint, lemon balm and coriander seed oils were most potent, with peppermint and coriander seed oils being more potent than the antibiotic rifaximin in the disc diffusion assay. The compounds present in these oils were identified by gas chromatography mass spectrometry. Finally, extracts were made of spearmint, lemon balm and coriander leaves with various solvents and these were tested for their antibacterial activity against E. coli in the disc diffusion assay. In each case, extracts made with ethanol and methanol exhibited potent antibacterial activity. Conclusions: Many of the essential oils had antibacterial activity in the three assays, suggesting that they would be good candidates for testing in clinical trials. The observed antibacterial activity of ethanolic extracts of coriander, lemon balm and spearmint leaves suggests a mechanistic explanation for the efficacy of a mixture of coriander, lemon balm and mint extracts against IBS in a published clinical trial.

Beschreibung: Background: The transport of sugars, hormones, amino acids, proteins, sugar alcohols, and other organic compounds from the sites of synthesis to the sites of use or storage occurs through the conducting cells of the phloem. To better understand these processes a comprehensive understanding of the proteins involved is required. While a considerable amount of data has been obtained from proteomic analyses of phloem sap, this has mainly served to identify the soluble proteins that are translocated through the phloem network. Results: In order to obtain more comprehensive proteomic data from phloem tissue we developed a simple dissection procedure to isolate phloem tissue from Brassica oleracea. The presence of a high density of phloem sieve elements was confirmed using light microscopy and fluorescently labeled sieve element-specific antibodies. To increase the depth of the proteomic analysis for membrane bound and associated proteins, soluble proteins were extracted first and subsequent extractions were carried out using two different detergents (SDS and CHAPSO). Across all three extractions almost four hundred proteins were identified and each extraction method added to the analysis demonstrating the utility of an approach combining several extraction protocols. Conclusions: The phloem was found to be enriched in proteins associated with biotic and abiotic stress responses and structural proteins. Subsequent expression analysis identified a number of genes that appear to be expressed exclusively or at very high levels in phloem tissue, including genes that are known to express specifically in the phloem as well as novel phloem genes.

Beschreibung: Background: Aboriginal Australians experience poorer outcomes from cancer compared to the non-Aboriginal population. Some progress has been made in understanding Aboriginal Australians' perspectives about cancer and their experiences with cancer services. However, little is known of cancer service providers' (CSPs) thoughts and perceptions regarding Aboriginal patients and their experiences providing optimal cancer care to Aboriginal people. Communication between Aboriginal patients and non-Aboriginal health service providers has been identified as an impediment to good Aboriginal health outcomes. This paper reports on CSPs' views about the factors impairing communication and offers practical strategies for promoting effective communication with Aboriginal patients in Western Australia (WA). Methods: A qualitative study involving in-depth interviews with 62 Aboriginal and non-Aboriginal CSPs from across WA was conducted between March 2006 - September 2007 and April-October 2011. CSPs were asked to share their experiences with Aboriginal patients and families experiencing cancer. Thematic analysis was carried out. Our analysis was primarily underpinned by the socio-ecological model and cultural security, but concepts of Whiteness and privilege, and cultural security also guided our analysis. Results: CSPs' lack of knowledge about the needs of Aboriginal people with cancer and Aboriginal patients' limited understanding of the western medical system were identified as the two major impediments to communication. For effective patient--provider communication, attention is needed to language, communication style, knowledge and use of medical terminology and cross-cultural differences in the concept of time. Aboriginal marginalization within mainstream society and Aboriginal people's distrust of the health system were also key issues impacting on communication. Potential solutions to effective Aboriginal patient-provider communication included recruiting more Aboriginal staff, providing appropriate cultural training for CSPs, cancer education for Aboriginal stakeholders, continuity of care, avoiding use of medical jargon, accommodating patients' psychosocial and logistical needs, and in-service coordination. Conclusion: Individual CSPs identified challenges in cross-cultural communication and their willingness to accommodate culture-specific needs within the wider health care system including better communication with Aboriginal patients. However, participants' comments indicated a lack of concerted effort at the system level to address Aboriginal disadvantage in cancer outcomes.

Beschreibung: Background: Discharge Against Medical Advice (DAMA) from hospital is associated with adverse outcomes and is considered an indicator of the responsiveness of hospitals to the needs of Aboriginal and Torres Strait Islander Australians, the indigenous people of Australia. We investigated demographic and clinical factors that predict DAMA in patients experiencing their first-ever inpatient admission for ischaemic heart disease (IHD). The study focuses particularly on the differences in the risk of DAMA in Aboriginal and non-Aboriginal patients while also investigating other factors in their own right. Methods: A cross-sectional analytical study was undertaken using linked hospital and mortality data with complete coverage of Western Australia. Participants included all first-ever IHD inpatients (aged 25--79 years) admitted between 2005 and 2009, selected after a 15-year clearance period and who were discharged alive. The main outcome measure was DAMA as reflected in the hospital record.Multiple logistic regression was used to determine disparities in DAMA between Aboriginal and non-Aboriginal patients, adjusting for a range of demographic and clinical factors, including comorbidity based on 5-year hospitalization history. A series of additional models were run on subgroups of the cohort to refine the analysis. Ethics approval was granted by the WA Human Research and the WA Aboriginal Health Ethics Committees. Results: Aboriginal patients comprised 4.3% of the cohort of 37,304 IHD patients and 23% of the 224 DAMAs. Emergency admission (OR=5.9, 95% CI 2.9-12.2), alcohol admission history (alcohol-related OR=2.9, 95% CI 2.0-4.2) and Aboriginality (OR 2.3, 95% CI 1.5-3.5) were the strongest predictors of DAMA in the multivariate model. Patients living in rural areas while attending non-metropolitan hospitals had a 50% higher risk of DAMA than those living and hospitalised in metropolitan areas. There was consistency in the ORs for Aboriginality in the different multivariate models using restricted sub-cohorts and different Aboriginal identifiers. Sex, IHD diagnosis type and co-morbidity scores imparted different risks in Aboriginal versus non-Aboriginal patients. Conclusions: Understanding the risks and reasons for DAMA is important for health system policy and proactive management of those at risk of DAMA. Improving care to prevent DAMA should target unplanned admissions, rural hospitals and young men, Aboriginal people and those with alcohol and mental health comorbidities.

Beschreibung: Background: Acute illness is common in childhood, and it is difficult for healthcare professionals to distinguish seriously ill children from the vast majority with minor or self-limiting illnesses. Safety netting provides parents with advice on when and where to return if their child deteriorates, and it is widely recommended that parents of acutely sick young children should be given safety netting advice. Yet little is known about how and when this is given. We aimed to understand what safety netting advice first contact clinicians give parents of acutely sick young children, how, when, and why. Methods: This was a qualitative study. Interviews and focus groups were held with doctors and nurses in a general practice surgery, a District General Hospital emergency department, a paediatric emergency department, and an out-of-hours service. Data were analysed using the method of constant comparison. Results: Sixteen clinicians participated. They described that safety netting advice includes advising parents what to look for, when and where to seek help. How safety netting was delivered and whether it was verbal or written was inconsistent, and no participants described being trained in this area. Safety netting appeared to be rarely documented, and was left to individual preference. Limitations of written materials, and structural barriers to the provision of safety netting, were perceived. Participants described that safety netting was influenced by clinicians' experience, confidence, time and knowledge; and perceived parental anxiety, experience, and competence. Participants noted several limitations to safety netting including not knowing if it has been understood by parents or been effective; parental difficulty interpreting information and desire for face-to-face reassurance; and potential over-reassurance. Conclusion: First contact clinicians employ a range of safety netting techniques, with inconsistencies within and between organisations. Structural changes, clinician training, and documentation in patient notes may improve safety netting provision. Research is needed into the optimal components of safety netting advice so that clinicians can consistently deliver the most effective advice for parents.

Beschreibung: Background: Carbon sources for biofuel production are wide-ranging and their availability depends on the climate and soil conditions of the land where the production chain is located. Henequen (Agave fourcroydes Lem.) is cultivated in Yucatan, Mexico to produce natural fibers from the leaves, and a juice containing fructans is produced during this process. Fructans can be hydrolyzed to fructose and glucose and metabolized into ethanol by appropriate yeasts. In Mexico, different Agave species provide the carbon source for (distilled and non-distilled) alcoholic beverage production using the stem of the plant, whilst the leaves are discarded. In this work, we investigated the effect of thermal acid and enzymatic hydrolysis of the juice on the amount of reducing sugars released. Growth curves were generated with the yeasts Saccharomyces cerevisiae and Kluyveromyces marxianus and fermentations were then carried out with Kluyveromyces marxianus to determine alcohol yields. Results: With thermal acid hydrolysis, the greatest increase in reducing sugars (82.6%) was obtained using 5% H2SO4 at 100[degree sign]C with a 30 min reaction time. Statistically similar results can be obtained using the same acid concentration at a lower temperature and with a shorter reaction time (60[degree sign]C, 15 min), or by using 1% H2SO4 at 100[degree sign]C with a 30 min reaction time. In the case of enzymatic hydrolysis, the use of 5.75, 11.47 and 22.82 U of enzyme did not produce significant differences in the increase in reducing sugars. Although both hydrolysis processes obtained similar results, the difference was observed after fermentation. Ethanol yields were 50.3 +/- 4 and 80.04 +/- 5.29% of the theoretical yield respectively. Conclusions: Final reducing sugars concentrations obtained with both thermal acid and enzymatic hydrolysis were similar. Saccharomyces cerevisiae, a good ethanol producer, did not grow in the hydrolysates. Only Kluyveromyces marxianus was able to grow in them, giving a higher ethanol yield with the enzymatic hydrolysate. The leaves account for a non-negligible weight of the total agave plant biomass, so this work complements the knowledge already developed on agave fermentations by making it possible to produce ethanol from almost the entire plant (stem and leaves).

Beschreibung: Background: Health professionals' behaviour is a key component in compliance with evidence-based recommendations. Opinion leaders are an oft-used method of influencing such behaviours in implementation studies, but reliably and cost effectively identifying them is not straightforward. Survey and questionnaire based data collection methods have potential and carefully chosen items can - in theory - both aid identification of opinion leaders and help in the design of an implementation strategy itself. This study compares two methods of identifying opinion leaders for behaviour-change interventions. Methods: Healthcare professionals working in a single UK mental health NHS Foundation Trust were randomly allocated to one of two questionnaires. The first, slightly longer questionnaire, asked for multiple nominations of opinion leaders, with specific information about the nature of the relationship with each nominee. The second, shorter version, asked simply for a list of named "champions" but no more additional information. We compared, using Chi Square statistics, both the questionnaire response rates and the number of health professionals likely to be influenced by the opinion leaders (i.e. the "coverage" rates) for both questionnaire conditions. Results: Both questionnaire versions had low response rates: only 15% of health professionals named colleagues in the longer questionnaire and 13% in the shorter version. The opinion leaders identified by both methods had a low number of contacts (range of coverage, 2-6 each). There were no significant differences in response rates or coverage between the two identification methods. Conclusions: The low response and population coverage rates for both questionnaire versions suggest that alternative methods of identifying opinion leaders for implementation studies may be more effective. Future research should seek to identify and evaluate alternative, non-questionnaire based, methods of identifying opinion leaders in order to maximise their potential in organisational behaviour change interventions.

Beschreibung: Background: Despite extensive literature demonstrating differing experiences in menopause around the world, documentation of the experience of menopause in Australian Aboriginal women is scarce thus their menopausal experience is relatively unknown. This study aimed to understand Australian Aboriginal women's understanding and experience of menopause and its impact on their lives. Methods: The study was an exploratory qualitative study. Twenty-five Aboriginal women were recruited from a regional centre in the Mid-West region of Western Australia using opportunistic and snowballing sampling. Interviews and focus group discussions were undertaken from February 2011 to February 2012 using open-ended questioning with a yarning technique. Thematic analysis was undertaken of the transcribed interviews. Results: A number of themes were revealed. These related to the language used, meanings and attitudes to menopause, symptoms experienced, the role of men, a lack of understanding, coping mechanisms and the attribution of menopausal changes to something else. The term "change of life" was more widely recognised and signified the process of ageing, and an associated gain of respect in the local community. A fear of menopausal symptoms or uncertainty about their origin was also common. Overall, many women reported insufficient understanding and a lack of available information to assist them and their family to understand the transition. Conclusion: There are similarities between Aboriginal and non-Aboriginal experiences of menopause, including similar symptom profiles. The current language used within mainstream health settings may not be appropriate to this population if it fails to recognise the importance of language and reflect the attributed meaning of menopause. The fear of symptoms and uncertainty of their relationship to menopause demonstrated a need for more information which has not adequately been supplied to Australian Aboriginal women through current services. While this study is with a select population of Aboriginal Australian women, it reveals the importance of acknowledging differences, particularly in use of language to convey ideas and support Aboriginal women experiencing menopause.