502 research outputs found

    Dexamethasone Treatment Induces the Reprogramming of Pancreatic Acinar Cells to Hepatocytes and Ductal Cells

    Get PDF
    The pancreatic exocrine cell line AR42J-B13 can be reprogrammed to hepatocytes following treatment with dexamethasone. The question arises whether dexamethasone also has the capacity to induce ductal cells as well as hepatocytes.AR42J-B13 cells were treated with and without dexamethasone and analyzed for the expression of pancreatic exocrine, hepatocyte and ductal markers. Addition of dexamethasone inhibited pancreatic amylase expression, induced expression of the hepatocyte marker transferrin as well as markers typical of ductal cells: cytokeratin 7 and 19 and the lectin peanut agglutinin. However, the number of ductal cells was low compared to hepatocytes. The proportion of ductal cells was enhanced by culture with dexamethasone and epidermal growth factor (EGF). We established several features of the mechanism underlying the transdifferentiation of pancreatic exocrine cells to ductal cells. Using a CK19 promoter reporter, we show that a proportion of the ductal cells arise from differentiated pancreatic exocrine-like cells. We also examined whether C/EBPβ (a transcription factor important in the conversion of pancreatic cells to hepatocytes) could alter the conversion from acinar cells to a ductal phenotype. Overexpression of an activated form of C/EBPβ in dexamethasone/EGF-treated cells provoked the expression of hepatocyte markers and inhibited the expression of ductal markers. Conversely, ectopic expression of a dominant-negative form of C/EBPβ, liver inhibitory protein, inhibited hepatocyte formation in dexamethasone-treated cultures and enhanced the ductal phenotype.These results indicate that hepatocytes and ductal cells may be induced from pancreatic exocrine AR42J-B13 cells following treatment with dexamethasone. The conversion from pancreatic to hepatocyte or ductal cells is dependent upon the expression of C/EBPβ

    Low birth weight activates the renin-angiotensin system, but limits cardiac angiogenesis in early postnatal life

    Get PDF
    Low birth weight (LBW) is associated with increased risk of adult cardiovascular disease and this association may be partly a consequence of early programming of the renin-angiotensin system (RAS). We investigated the effects of LBW on expression of molecules in the RAS and cardiac tissue remodeling. Left ventricular samples were collected from the hearts of 21 days old lambs that were born average birth weight (ABW) and LBW. Cardiac mRNA expression was quantified using real-time RT-PCR and protein expression was quantified using Western blotting. DNA methylation and histone acetylation were assessed by combined bisulfite restriction analysis and chromatin immunoprecipitation, respectively. There were increased plasma renin activity, angiotensin I (ANGI), and ANGII concentrations in LBW compared to ABW lambs at day 20. In LBW lambs, there was increased expression of cardiac ACE2 mRNA, decreased ANGII receptor type 1 (AT1R) protein, and acetylation of histone H3K9 of the AT1R promoter but no changes in AT1R mRNA expression and AT1R promoter DNA methylation. There was no difference in the abundance of proteins involved in autophagy or fibrosis. BIRC5 and VEGF mRNA expression was increased; however, the total length of the capillaries was decreased in the hearts of LBW lambs. Activation of the circulating and local cardiac RAS in neonatal LBW lambs may be expected to increase cardiac fibrosis, autophagy, and capillary length. However, we observed only a decrease in total capillary length, suggesting a dysregulation of the RAS in the heart of LBW lambs and this may have significant implications for heart health in later life.Kimberley C. W. Wang, Doug A. Brooks, Brooke Summers‐Pearce, Larisa Bobrovskaya, Darran N. Tosh, Jaime A. Duffield, Kimberley J. Botting, Song Zhang, I. Caroline McMillen, Janna L. Morriso

    EQ-5D in skin conditions: an assessment of validity and responsiveness

    Get PDF
    Aims and objectives This systematic literature review aims to assess the reliability, validity and responsiveness of three widely used generic preference-based measures of health-related quality of life (HRQL), i.e., EQ-5D, Health Utility Index 3 (HUI3) and SF-6D in patients with skin conditions. Methods A systematic search was conducted to identify studies reporting health state utility values obtained using EQ-5D, SF-6D, or HUI3 alongside other HRQL measures or clinical indices for patients with skin conditions. Data on test-retest analysis for reliability, known group differences or correlation and regression analyses for validity, and change over time or responsiveness indices analysis were extracted and reviewed. Results A total of 16 papers reporting EQ-5D utilities in people with skin conditions were included in the final review. No papers for SF-6D and HUI3 were found. Evidence of reliability was not found for any of these measures. The majority of studies included in the review (12 out of 16) examined patients with plaque psoriasis or psoriatic arthritis and the remaining four studies examined patients with either acne, hidradenitis suppurativa, hand eczema, or venous leg ulcers. The findings were generally positive in terms of performance of EQ-5D. Six studies showed that EQ-5D was able to reflect differences between severity groups and only one reported differences that were not statistically significant. Four studies found that EQ-5D detected differences between patients and the general population, and differences were statistically different for three of them. Further, moderate-to-strong correlation coefficients were found between EQ-5D and other skin-specific HRQL measures in four studies. Eight studies showed that EQ-5D was able to detect change in HRQL appropriately over time and the changes were statistically significant in seven studies. Conclusions Overall, the validity and responsiveness of the EQ-5D was found to be good in people with skin diseases, especially plaque psoriasis or psoriatic arthritis. No evidence on SF-6D and HUI3 was available to enable any judgments to be made on their performance

    Expression and trans-specific polymorphism of self-incompatibility RNases in Coffea (Rubiaceae)

    Get PDF
    Self-incompatibility (SI) is widespread in the angiosperms, but identifying the biochemical components of SI mechanisms has proven to be difficult in most lineages. Coffea (coffee; Rubiaceae) is a genus of old-world tropical understory trees in which the vast majority of diploid species utilize a mechanism of gametophytic self-incompatibility (GSI). The S-RNase GSI system was one of the first SI mechanisms to be biochemically characterized, and likely represents the ancestral Eudicot condition as evidenced by its functional characterization in both asterid (Solanaceae, Plantaginaceae) and rosid (Rosaceae) lineages. The S-RNase GSI mechanism employs the activity of class III RNase T2 proteins to terminate the growth of "self" pollen tubes. Here, we investigate the mechanism of Coffea GSI and specifically examine the potential for homology to S-RNase GSI by sequencing class III RNase T2 genes in populations of 14 African and Madagascan Coffea species and the closely related self-compatible species Psilanthus ebracteolatus. Phylogenetic analyses of these sequences aligned to a diverse sample of plant RNase T2 genes show that the Coffea genome contains at least three class III RNase T2 genes. Patterns of tissue-specific gene expression identify one of these RNase T2 genes as the putative Coffea S-RNase gene. We show that populations of SI Coffea are remarkably polymorphic for putative S-RNase alleles, and exhibit a persistent pattern of trans-specific polymorphism characteristic of all S-RNase genes previously isolated from GSI Eudicot lineages. We thus conclude that Coffea GSI is most likely homologous to the classic Eudicot S-RNase system, which was retained since the divergence of the Rubiaceae lineage from an ancient SI Eudicot ancestor, nearly 90 million years ago.United States National Science Foundation [0849186]; Society of Systematic Biologists; American Society of Plant Taxonomists; Duke University Graduate Schoolinfo:eu-repo/semantics/publishedVersio

    Special topic: The association between pulse ingredients and canine dilated cardiomyopathy: addressing the knowledge gaps before establishing causation.

    Get PDF
    In July 2018, the Food and Drug Administration warned about a possible relationship between dilated cardiomyopathy (DCM) in dogs and the consumption of dog food formulated with potatoes and pulse ingredients. This issue may impede utilization of pulse ingredients in dog food or consideration of alternative proteins. Pulse ingredients have been used in the pet food industry for over 2 decades and represent a valuable source of protein to compliment animal-based ingredients. Moreover, individual ingredients used in commercial foods do not represent the final nutrient concentration of the complete diet. Thus, nutritionists formulating dog food must balance complementary ingredients to fulfill the animal's nutrient needs in the final diet. There are multiple factors that should be considered, including differences in nutrient digestibility and overall bioavailability, the fermentability and quantity of fiber, and interactions among food constituents that can increase the risk of DCM development. Taurine is a dispensable amino acid that has been linked to DCM in dogs. As such, adequate supply of taurine and/or precursors for taurine synthesis plays an important role in preventing DCM. However, requirements of amino acids in dogs are not well investigated and are presented in total dietary content basis which does not account for bioavailability or digestibility. Similarly, any nutrient (e.g., soluble and fermentable fiber) or physiological condition (e.g., size of the dog, sex, and age) that increases the requirement for taurine will also augment the possibility for DCM development. Dog food formulators should have a deep knowledge of processing methodologies and nutrient interactions beyond meeting the Association of American Feed Control Officials nutrient profiles and should not carelessly follow unsubstantiated market trends. Vegetable ingredients, including pulses, are nutritious and can be used in combination with complementary ingredients to meet the nutritional needs of the dog

    Squaring the circle: a priority-setting method for evidence-based service development, reconciling research with multiple stakeholder views.

    Get PDF
    BACKGROUND: This study demonstrates a technique to aid the implementation of research findings through an example of improving services and self-management in longer-term depression. In common with other long-term conditions, policy in this field requires innovation to be undertaken in the context of a whole system of care, be cost-effective, evidence-based and to comply with national clinical guidelines. At the same time, successful service development must be acceptable to clinicians and service users and choices must be made within limited resources. This paper describes a novel way of resolving these competing requirements by reconciling different sources and types of evidence and systematically engaging multiple stakeholder views. METHODS: The study combined results from mathematical modelling of the care pathway, research evidence on effective interventions and findings from qualitative research with service users in a series of workshops to define, refine and select candidate service improvements. A final consensus-generating workshop used structured discussion and anonymised electronic voting. This was followed by an email survey to all stakeholders, to achieve a pre-defined criterion of consensus for six suggestions for implementation. RESULTS: An initial list of over 20 ideas was grouped into four main areas. At the final workshop, each idea was presented in person, visually and in writing to 40 people, who assigned themselves to one or more of five stakeholder groups: i) service users and carers, ii) clinicians, iii) managers, iv) commissioners and v) researchers. Many belonged to more than one group. After two rounds of voting, consensus was reached on seven ideas and one runner up. The survey then confirmed the top six ideas to be tested in practice. CONCLUSIONS: The method recruited and retained people with diverse experience and views within a health community and took account of a full range of evidence. It enabled a diverse group of stakeholders to travel together in a direction that converged with the messages coming out of the research and successfully yielded priorities for service improvement that met competing requirements

    Trisomy of human chromosome 21 enhances amyloid-β deposition independently of an extra copy of APP

    Get PDF
    Down syndrome, caused by trisomy of chromosome 21, is the single most common risk factor for early-onset Alzheimer's disease. Worldwide approximately 6 million people have Down syndrome, and all these individuals will develop the hallmark amyloid plaques and neurofibrillary tangles of Alzheimer's disease by the age of 40 and the vast majority will go on to develop dementia. Triplication of APP, a gene on chromosome 21, is sufficient to cause early-onset Alzheimer's disease in the absence of Down syndrome. However, whether triplication of other chromosome 21 genes influences disease pathogenesis in the context of Down syndrome is unclear. Here we show, in a mouse model, that triplication of chromosome 21 genes other than APP increases amyloid-β aggregation, deposition of amyloid-β plaques and worsens associated cognitive deficits. This indicates that triplication of chromosome 21 genes other than APP is likely to have an important role to play in Alzheimer's disease pathogenesis in individuals who have Down syndrome. We go on to show that the effect of trisomy of chromosome 21 on amyloid-β aggregation correlates with an unexpected shift in soluble amyloid-β 40/42 ratio. This alteration in amyloid-β isoform ratio occurs independently of a change in the carboxypeptidase activity of the γ-secretase complex, which cleaves the peptide from APP, or the rate of extracellular clearance of amyloid-β. These new mechanistic insights into the role of triplication of genes on chromosome 21, other than APP, in the development of Alzheimer's disease in individuals who have Down syndrome may have implications for the treatment of this common cause of neurodegeneration

    The necessity of historical inquiry in educational research: the case of Religious Education

    Get PDF
    publication-status: PublishedThis is an Author's Original Manuscript of an article whose final and definitive form, the Version of Record, has been published in the British Journal of Religious Education, July 2010. Available online at: http://www.tandfonline.com/ or DOI: 10.1080/01416200.2010.498612This article explores the mixed fortunes of historical inquiry as a method in educational studies and exposes evidence for the neglect of this method in religious education research in particular. It argues that historical inquiry, as a counterpart to other research methods, can add depth and range to our understanding of education, including religious education, and can illuminate important longer‐term, broader and philosophical issues. The article also argues that many historical voices have remained silent in the existing historiography of religious education because such historiography is too generalised and too biased towards the development of national policy and curriculum and pedagogical theory. To address this limitation in educational research, this article promotes rigorous historical studies that are more substantially grounded in the appropriate historiographical literature and utilise a wide range of original primary sources. Finally, the article explores a specific example of the way in which a historical approach may be fruitfully applied to a particular contemporary debate concerning the nature and purpose of religious education
    corecore