2,727 research outputs found

    A national survey on the patterns of treatment of inflammatory bowel disease in Canada

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    BACKGROUND: There is a general lack of information on the care of inflammatory bowel disease (IBD) in a broad, geographically diverse, non-clinic population. The purposes of this study were (1) to compare a sample drawn from the membership of a national Crohn's and Colitis Foundation to published clinic-based and population-based IBD samples, (2) to describe current patterns of health care use, and (3) to determine if unexpected variations exist in how and by whom IBD is treated. METHODS: Mailed survey of 4453 members of the Crohn's and Colitis Foundation of Canada. The questionnaire, in members stated language of preference, included items on demographic and disease characteristics, general health behaviors and current and past IBD treatment. Each member received an initial and one reminder mailing. RESULTS: Questionnaires were returned by 1787, 913, and 128 people with Crohn's disease, ulcerative colitis and indeterminate colitis, respectively. At least one operation had been performed on 1159 Crohn's disease patients, with risk increasing with duration of disease. Regional variation in surgical rates in ulcerative colitis patients was identified. 6-Mercaptopurine/Azathioprine was used by 24% of patients with Crohn's disease and 12% of patients with ulcerative colitis (95% CI for the difference: 8.9% – 15%). In patients with Crohn's disease, use was not associated with gender, income or region of residence but was associated with age and markers of disease activity. Infliximab was used by 112 respondents (4%), the majority of whom had Crohn's disease. Variations in infliximab use based on region of residence and income were not seen. Sixty-eight percent of respondents indicated that they depended most on a gastroenterologist for their IBD care. There was significant regional variation in this. However, satisfaction with primary physician did not depend on physician type (for example, gastroenterologist versus general practitioner). CONCLUSION: This study achieved the goal of obtaining a large, geographically diverse sample that is more representative of the general IBD population than a clinic sample would have been. We could find no evidence of significant regional variation in medical treatments due to gender, region of residence or income level. Differences were noted between different age groups, which deserves further attention

    Antigenic Complementarity in the Origins of Autoimmunity: A General Theory Illustrated With a Case Study of Idiopathic Thrombocytopenia Purpura

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    We describe a novel, testable theory of autoimmunity, outline novel predictions made by the theory, and illustrate its application to unravelling the possible causes of idiopathic thrombocytopenia purpura (ITP). Pairs of stereochemically complementary antigens induce complementary immune responses (antibody or T-cell) that create loss of regulation and civil war within the immune system itself. Antibodies attack antibodies creating circulating immune complexes; T-cells attack T-cells creating perivascular cuffing. This immunological civil war abrogates the self-nonself distinction. If at least one of the complementary antigens mimics a self antigen, then this unregulated immune response will target host tissues as well. Data demonstrating that complementary antigens are found in some animal models of autoimmunity and may be present in various human diseases, especially ITP, are reviewed. Specific mechanisms for preventing autoimmunity or suppressing existing autoimmunity are derived from the theory, and critical tests proposed. Finally, we argue that Koch's postulates are inadequate for establishing disease causation for multiple-antigen diseases and discuss the possibility that current research has failed to elucidate the causes of human autoimmune diseases because we are using the wrong criteria

    Beyond ‘crude pragmatism’ in sports coaching:Insights from C.S. Peirce, William James and John Dewey: a commentary

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    We agree that there is a lack of clarity in the sports coaching literature about philosophical pragmatism, but this is inevitable when there is a lack of consensus in the literature of philosophical pragmatism itself. In the writing of classical pragmatists there are a “plurality of conflicting narratives” (Bernstein, 1995 p.55). For instance, Charles Sanders Peirce acknowledged notable theoretical divergence between his pragmatism and that of William James (Hookway, 2012). In fact, Peirce viewed the availability of nuanced approaches as a mark of the vitality of this school of thought. After all, pragmatists value diversity, they accept that current thinking, hypotheses and practices may require revision – they are flexibly minded. Such revision, however, must be built upon well-reasoned doubt (Hookway, 2012). In other words, a clear argument is necessary if an alternative proposition is to be considered. In this vein, though we have sympathy for the thrust of his argument, and support calls for more “legitimate philosophical thinking” and “empirical philosophical enquiry” (Cushion & Partington, 2016 p.863), our aim in this commentary is to address a lack of clarity and utility in some of Jenkins’ propositions about philosophical pragmatism and sports coaching

    Prostate Cancer and Race

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72215/1/j.1525-1497.2003.30801.x.pd

    Induction of microRNAs, mir-155, mir-222, mir-424 and mir-503, promotes monocytic differentiation through combinatorial regulation

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    Acute myeloid leukemia (AML) involves a block in terminal differentiation of the myeloid lineage and uncontrolled proliferation of a progenitor state. Using phorbol myristate acetate (PMA), it is possible to overcome this block in THP-1 cells (an M5-AML containing the MLL-MLLT3 fusion), resulting in differentiation to an adherent monocytic phenotype. As part of FANTOM4, we used microarrays to identify 23 microRNAs that are regulated by PMA. We identify four PMA-induced micro- RNAs (mir-155, mir-222, mir-424 and mir-503) that when overexpressed cause cell-cycle arrest and partial differentiation and when used in combination induce additional changes not seen by any individual microRNA. We further characterize these prodifferentiative microRNAs and show that mir-155 and mir-222 induce G2 arrest and apoptosis, respectively. We find mir-424 and mir-503 are derived from a polycistronic precursor mir-424-503 that is under repression by the MLL-MLLT3 leukemogenic fusion. Both of these microRNAs directly target cell-cycle regulators and induce G1 cell-cycle arrest when overexpressed in THP-1. We also find that the pro-differentiative mir-424 and mir-503 downregulate the anti-differentiative mir-9 by targeting a site in its primary transcript. Our study highlights the combinatorial effects of multiple microRNAs within cellular systems.Comment: 45 pages 5 figure

    Advancing the public health applications of Chlamydia trachomatis serology

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    © 2018 Elsevier Ltd Genital Chlamydia trachomatis infection is the most commonly diagnosed sexually transmitted infection. Trachoma is caused by ocular infection with C trachomatis and is the leading infectious cause of blindness worldwide. New serological assays for C trachomatis could facilitate improved understanding of C trachomatis epidemiology and prevention. C trachomatis serology offers a means of investigating the incidence of chlamydia infection and might be developed as a biomarker of scarring sequelae, such as pelvic inflammatory disease. Therefore, serological assays have potential as epidemiological tools to quantify unmet need, inform service planning, evaluate interventions including screening and treatment, and to assess new vaccine candidates. However, questions about the performance characteristics and interpretation of C trachomatis serological assays remain, which must be addressed to advance development within this field. In this Personal View, we explore the available information about C trachomatis serology and propose several priority actions. These actions involve development of target product profiles to guide assay selection and assessment across multiple applications and populations, establishment of a serum bank to facilitate assay development and evaluation, and development of technical and statistical methods for assay evaluation and analysis of serological findings. The field of C trachomatis serology will benefit from collaboration across the public health community to align technological developments with their potential applications

    On the Action of Methotrexate and 6-Mercaptopurine on M. avium Subspecies paratuberculosis

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    BACKGROUND: Clinical improvement in inflammatory bowel disease (IBD) treated with methotrexate and 6-mercaptopurine (6-MP) is associated with a decrease in pro-inflammatory cytokines. This has been presumed to indicate the mechanism of action of methotrexate and 6-MP. Although controversial, there are increasingly compelling data that Mycobacterium avium subspecies paratuberculosis (MAP) may be an etiological agent in some or all of IBD. We hypothesized that the clinical efficacy of methotrexate and 6-MP in IBD may be to simply inhibit the growth of MAP. METHODOLOGY: The effect on MAP growth kinetics by methotrexate and 6-MP were evaluated in cell culture of two strains each of MAP and M. avium using a radiometric ((14)CO(2) BACTEC®) detection system that quantifies mycobacterial growth as arbitrary “growth index units” (GI). Efficacy data are presented as “percent decrease in cumulative GI” (% −ΔcGI). PRINCIPAL FINDINGS: The positive control antibiotic (clarithromycin) has ≥85% −ΔcGI at a concentration of 0.5 µg/ml. The negative control (ampicillin) has minimal inhibition at 64 µg/ml. MAP ATCC 19698 shows ≥80% −ΔcGI for both agents by 4 µg/ml. With the other three isolates, although more effective than ampicillin, 6-MP is consistently less effective than methotrexate. CONCLUSIONS: We show that methotrexate and 6-MP inhibit MAP growth in vitro. Each of the four isolates manifests different % −ΔcGI. These data are compatible with the hypothesis that the clinical improvement in patients with IBD treated with methotrexate and 6-MP could be due to treating a MAP infection. The decrease in pro-inflammatory cytokines, thought to be the primary mechanism of action, may simply be a normal, secondary, physiological response. We conclude that henceforth, in clinical studies that evaluate the effect of anti-MAP agents in IBD, the use of methotrexate and 6-MP should be excluded from any control groups

    Horizontal DNA transfer mechanisms of bacteria as weapons of intragenomic conflict

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    Horizontal DNA transfer (HDT) is a pervasive mechanism of diversification in many microbial species, but its primary evolutionary role remains controversial. Much recent research has emphasised the adaptive benefit of acquiring novel DNA, but here we argue instead that intragenomic conflict provides a coherent framework for understanding the evolutionary origins of HDT. To test this hypothesis, we developed a mathematical model of a clonally descended bacterial population undergoing HDT through transmission of mobile genetic elements (MGEs) and genetic transformation. Including the known bias of transformation toward the acquisition of shorter alleles into the model suggested it could be an effective means of counteracting the spread of MGEs. Both constitutive and transient competence for transformation were found to provide an effective defence against parasitic MGEs; transient competence could also be effective at permitting the selective spread of MGEs conferring a benefit on their host bacterium. The coordination of transient competence with cell-cell killing, observed in multiple species, was found to result in synergistic blocking of MGE transmission through releasing genomic DNA for homologous recombination while simultaneously reducing horizontal MGE spread by lowering the local cell density. To evaluate the feasibility of the functions suggested by the modelling analysis, we analysed genomic data from longitudinal sampling of individuals carrying Streptococcus pneumoniae. This revealed the frequent within-host coexistence of clonally descended cells that differed in their MGE infection status, a necessary condition for the proposed mechanism to operate. Additionally, we found multiple examples of MGEs inhibiting transformation through integrative disruption of genes encoding the competence machinery across many species, providing evidence of an ongoing "arms race." Reduced rates of transformation have also been observed in cells infected by MGEs that reduce the concentration of extracellular DNA through secretion of DNases. Simulations predicted that either mechanism of limiting transformation would benefit individual MGEs, but also that this tactic's effectiveness was limited by competition with other MGEs coinfecting the same cell. A further observed behaviour we hypothesised to reduce elimination by transformation was MGE activation when cells become competent. Our model predicted that this response was effective at counteracting transformation independently of competing MGEs. Therefore, this framework is able to explain both common properties of MGEs, and the seemingly paradoxical bacterial behaviours of transformation and cell-cell killing within clonally related populations, as the consequences of intragenomic conflict between self-replicating chromosomes and parasitic MGEs. The antagonistic nature of the different mechanisms of HDT over short timescales means their contribution to bacterial evolution is likely to be substantially greater than previously appreciated
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