24 research outputs found

    Deep EST profiling of developing fenugreek endosperm to investigate galactomannan biosynthesis and its regulation

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    Galactomannans are hemicellulosic polysaccharides composed of a (1 → 4)-linked β-D-mannan backbone substituted with single-unit (1 → 6)-α-linked D-galactosyl residues. Developing fenugreek (Trigonella foenum-graecum) seeds are known to accumulate large quantities of galactomannans in the endosperm, and were thus used here as a model system to better understand galactomannan biosynthesis and its regulation. We first verified the specific deposition of galactomannans in developing endosperms and determined that active accumulation occurred from 25 to 38 days post anthesis (DPA) under our growth conditions. We then examined the expression levels during seed development of ManS and GMGT, two genes encoding backbone and side chain synthetic enzymes. Based on transcript accumulation dynamics for ManS and GMGT, cDNA libraries were constructed using RNA isolated from endosperms at four ages corresponding to before, at the beginning of, and during active galactomannan deposition. DNA from these libraries was sequenced using the 454 sequencing technology to yield a total of 1.5 million expressed sequence tags (ESTs). Through analysis of the EST profiling data, we identified genes known to be involved in galactomannan biosynthesis, as well as new genes that may be involved in this process, and proposed a model for the flow of carbon from sucrose to galactomannans. Measurement of in vitro ManS and GMGT activities and analysis of sugar phosphate and nucleotide sugar levels in the endosperms of developing fenugreek seeds provided data consistent with this model. In vitro enzymatic assays also revealed that the ManS enzyme from fenugreek endosperm preferentially used GDP-mannose as the substrate for the backbone synthesis

    Decelerating Spread of West Nile Virus by Percolation in a Heterogeneous Urban Landscape

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    Vector-borne diseases are emerging and re-emerging in urban environments throughout the world, presenting an increasing challenge to human health and a major obstacle to development. Currently, more than half of the global population is concentrated in urban environments, which are highly heterogeneous in the extent, degree, and distribution of environmental modifications. Because the prevalence of vector-borne pathogens is so closely coupled to the ecologies of vector and host species, this heterogeneity has the potential to significantly alter the dynamical systems through which pathogens propagate, and also thereby affect the epidemiological patterns of disease at multiple spatial scales. One such pattern is the speed of spread. Whereas standard models hold that pathogens spread as waves with constant or increasing speed, we hypothesized that heterogeneity in urban environments would cause decelerating travelling waves in incipient epidemics. To test this hypothesis, we analysed data on the spread of West Nile virus (WNV) in New York City (NYC), the 1999 epicentre of the North American pandemic, during annual epizootics from 2000–2008. These data show evidence of deceleration in all years studied, consistent with our hypothesis. To further explain these patterns, we developed a spatial model for vector-borne disease transmission in a heterogeneous environment. An emergent property of this model is that deceleration occurs only in the vicinity of a critical point. Geostatistical analysis suggests that NYC may be on the edge of this criticality. Together, these analyses provide the first evidence for the endogenous generation of decelerating travelling waves in an emerging infectious disease. Since the reported deceleration results from the heterogeneity of the environment through which the pathogen percolates, our findings suggest that targeting control at key sites could efficiently prevent pathogen spread to remote susceptible areas or even halt epidemics

    New insights into the molecular mechanisms of general anaesthetics

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    This paper provides new insights of how general anaesthetic research should be carried out in the future by an analysis of what we know, what we do not know and what we would like to know. I describe previous hypotheses on the mechanism of action of general anaesthetics (GAs) involving membranes and protein receptors. I provide the reasons why the GABA type A receptor, the NMDA receptor and the glycine receptor are strong candidates for the sites of action of GAs. I follow with a review on attempts to provide a mechanism of action, and how future research should be conducted with the help of physical and chemical methods

    Buprenorphine/Naloxone for opioid dependence: clinical practice guideline.

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    • The objective of this guideline is to provide clinical recommendations for the initiation, maintenance and discontinuation of buprenorphine/naloxone maintenance treatment in the ambulatory treatment of adults and adolescents with opioid dependence in Ontario. • The guideline intends to contribute to education of practitioners regarding opioid prescribing, improved patient access to treatment for opioid dependence, and safe prescribing and dispensing of buprenorphine/naloxone. • This evidence-based clinical practice guideline was developed by a multidisciplinary committee, and included specialists in the field of addiction medicine, family medicine and pharmacy. • A systematic review of the literature formed the evidence base for this guideline, and recommendations were assigned levels of evidence and grades of recommendations based on those developed by the Canadian Task Force on Preventive Health Care

    Provider training and experience for people living with HIV/AIDS

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    BACKGROUND: The complexity of HIV/AIDS raises challenges for the effective delivery of care. It is important to ensure that the expertise and experience of care providers is of high quality. Training and experience of HIV/AIDS providers may impact not only individual patient outcomes but increasingly on health care costs as well. OBJECTIVE: The objective of this review is to assess the effects of provider training and experience on people living with HIV/AIDS on the following outcomes: immunological (ie. viral load, CD4 count), medical (ie. mortality, proportion on antiretrovirals), psychosocial (ie. quality of life measures) and economic outcomes (ie health care costs). CRITERIA FOR CONSIDERING STUDIES FOR THIS REVIEW: We searched MEDLINE, EMBASE, Dissertation Abstracts International (DAI), CINAHL, HealthStar, PsycInfo, PsycLit, Social Sciences Abstracts, and Sociological Abstracts from January 1, 1980 through May 29, 2009. Electronic searches were performed for abstracts from major international AIDS conferences. Reference lists from pertinent articles, books and review articles were retrieved and reviewed. SELECTION CRITERIA: Randomized controlled trials (RCTs), controlled clinical trials, cohort, case control, cross-sectional studies and controlled before and after designs that examined the qualifications/training and patient volume of HIV/AIDS care of providers caring for persons known to be infected with HIV/AIDS were included. DATA COLLECTION AND ANALYSIS: At least two authors independently assessed trial quality and extracted data. Study authors were contacted for further information as required. Assessment of confounding factors was undertaken independently by two reviewers. MAIN RESULTS: A total of four studies (one randomized controlled trial, three non- randomized studies) involving 8488 people living with HIV/AIDS were included. The main findings of this review demonstrated a trend to improved outcomes when treated by a provider with more training/expertise in HIV/AIDS care in the outpatient (clinic) setting. Due to the heterogeneity of the included studies, we could not perform a meta-analysis. We present a descriptive review of the results. AUTHORS' CONCLUSIONS: The results demonstrate improved medical outcomes when treated by a provider with more training/expertise in HIV/AIDS care in the outpatient (clinic) setting. Since all of these studies were conducted in North America, this does not address any issues regarding the level of training/expertise required by providers working in countries with more limited resources. Practitioners who do not consider themselves "experts" in HIV/AIDS care and care for few of these patients need to seriously consider this review which demonstrates a trend towards worse patient outcomes when receiving care by those with low caseloads/training in HIV/AIDS care

    Resuscitation simulation among people who are likely to witness opioid overdose: Experiences from the SOONER Trial.

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    The opioid crisis is a growing public health emergency and increasing resources are being directed towards overdose education. Simulation has emerged as a novel strategy for training overdose response, yet little is known about training non-clinicians in bystander resuscitation. Understanding the perspectives of individuals who are likely to experience or witness opioid overdose is critical to ensure that emergency response is effective. The Surviving Opioid Overdose with Naloxone Education and Resuscitation (SOONER) study evaluates the effectiveness of a novel naloxone education and distribution tool among people who are non-clinicians and likely to witness opioid overdose. Participants' resuscitation skills are evaluated using a realistic overdose simulation as the primary outcome of the trial. The purpose of our study is to describe the experience of participants with the simulation process in the SOONER study. We employed a semi-structured debriefing interview and a follow up qualitative interview to understand the experience of participants with simulation. A qualitative content analysis was performed using data from 21 participants who participated in the SOONER study. Our qualitative analysis identified 5 themes and 17 subthemes which described the experience of participants within the simulation process. These themes included realism, valuing practical experience, improving self-efficacy, gaining new perspective and bidirectional learning. Our analysis found that simulation was a positive and empowering experience for participants in the SOONER trial, most of whom are marginalized in society. Our study supports the notion that expanding simulation-based education to non-clinicians may offer an acceptable and effective way of supplementing current opioid overdose education strategies. Increasing the accessibility of simulation-based education may represent a paradigm shift whereby simulation is transformed from a primarily academic practice into a patient-based community resource

    Considerations for the design of overdose education and naloxone distribution interventions: results of a multi-stakeholder workshop

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    Abstract Introduction Opioid overdose epidemic is a public health crisis that is impacting communities around the world. Overdose education and naloxone distribution programs equip and train lay people to respond in the event of an overdose. We aimed to understand factors to consider for the design of naloxone distribution programs in point-of-care settings from the point of view of community stakeholders. Methods We hosted a multi-stakeholder co-design workshop to elicit suggestions for a naloxone distribution program. We recruited people with lived experience of opioid overdose, community representatives, and other stakeholders from family practice, emergency medicine, addictions medicine, and public health to participate in a full-day facilitated co-design discussion wherein large and small group discussions were audio-recorded, transcribed and analysed using thematic approaches. Results A total of twenty-four participants participated in the multi-stakeholder workshop from five stakeholder groups including geographic and setting diversity. Collaborative dialogue and shared storytelling revealed seven considerations for the design of naloxone distribution programs specific to training needs and the provision of naloxone, these are: recognizing overdose, how much naloxone, impact of stigma, legal risk of responding, position as conventional first aid, friends and family as responders, support to call 911. Conclusion To create an naloxone distribution program in emergency departments, family practice and substance use treatment services, stigma is a central design consideration for training and naloxone kits. Design choices that reference the iconography, type, and form of materials associated with first aid have the potential to satisfy the need to de-stigmatize overdose response
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