384 research outputs found

    \u27Candidatus Xenohaliotis californiensis\u27, a newly described pathogen of abalone, Haliotis spp., along the west coast of North America

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    Withering syndrome is a fatal disease of wild and cultured abalone. Haliotis spp., that inhabit the west coast of North America. The aetiological agent of withering syndrome has recently been identified as a member of the family Rickettsiaceae in the order Rickettsiales. Using a combination of morphological, serological, life history and genomic (16S rDNA) characterization. we have identified this bacterium as a unique taxon and propose the provisional status of \u27Candidatus Xenohaliotis californiensis\u27, The Gram-negative. obligate intracellular pleomorphic bacterium is found within membrane-bound vacuoles in the cytoplasm of abalone gastrointestinal epithelial cells. The bacterium is not cultivable on synthetic media or in fish cell lines (e.g. CHSE-214) and may be controlled by tetracyclines (oxytetracycline) but not by chloramphenicol, clarithromycin or sarafloxicin. Phylogenetic analysis based on the 16S rDNA of \u27Candidatus Xenohaliotis californiensis\u27 places it in the alpha-subclass of the class Proteobacteria but not to the four recognized subtaxa of the alpha-Proteobacteria (alpha-1, alpha-2, alpha-3 and alpha-4). The bacterium can be detected in tissue squashes stained with propidium iodide, microscopic examination of stained tissue sections, PCR or in situ hybridization. \u27Candidatus Xenohaliotis californiensis\u27 can be differentiated from other closely related alpha-Proteobacteria by its unique 16S rDNA sequence

    The principle of respect for autonomy – Concordant with the experience of oncology physicians and molecular biologists in their daily work?

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    <p>Abstract</p> <p>Background</p> <p>This article presents results from a qualitative empirical investigation of how Danish oncology physicians and Danish molecular biologists experience the principle of respect for autonomy in their daily work.</p> <p>Methods</p> <p>This study is based on 12 semi-structured interviews with three groups of respondents: a group of oncology physicians working in a clinic at a public hospital and two groups of molecular biologists conducting basic research, one group employed at a public university and the other in a private biopharmaceutical company.</p> <p>Results</p> <p>We found that that molecular biologists consider the principle of respect for autonomy as a negative obligation, where the informed consent of patients or research subjects should be respected. Furthermore, molecular biologists believe that very sick patients are constraint by the circumstances to a certain choice. However, in contrast to molecular biologists, oncology physicians experience the principle of respect for autonomy as a positive obligation, where the physician in dialogue with the patient performs a medical prognosis based on the patient's wishes and ideas, mutual understanding and respect. Oncology physicians believe that they have a positive obligation to adjust to the level of the patient when providing information making sure that the patient understands. Oncology physicians experience situations where the principle of respect for autonomy does not apply because the patient is in a difficult situation.</p> <p>Conclusion</p> <p>In this study we explore the moral views and attitudes of oncology physicians and molecular biologists and compare these views with bioethical theories of the American bioethicists Tom L. Beauchamp & James F. Childress and the Danish philosophers Jakob Rendtorff & Peter Kemp. This study shows that essential parts of the two bioethical theories are reflected in the daily work of Danish oncology physicians and Danish molecular biologists. However, the study also explores dimensions where the theories can be developed further to be concordant with biomedical practice. The hope is that this study enhances the understanding of the principle of respect for autonomy and the way it is practiced.</p

    Poverty and maternal mortality in Nigeria: towards a more viable ethics of modern medical practice

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    Poverty is often identified as a major barrier to human development. It is also a powerful brake on accelerated progress toward the Millennium Development Goals. Poverty is also a major cause of maternal mortality, as it prevents many women from getting proper and adequate medical attention due to their inability to afford good antenatal care. This Paper thus examines poverty as a threat to human existence, particularly women's health. It highlights the causes of maternal deaths in Nigeria by questioning the practice of medicine in this country, which falls short of the ethical principle of showing care

    An Ethical Façade? Medical Students' Miscomprehensions of Substituted Judgment

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    Background: We studied how well first-year medical students understand and apply the concept of substituted judgment, following a course on clinical ethics. Method: Students submitted essays on one of three ethically controversial scenarios presented in class. One scenario involved a patient who had lost decisional capacity. Through an iterative process of textual analysis, the essays were studied and coded for patterns in the ways students misunderstood or misapplied the principle of substituted judgment. Results: Students correctly articulated course principles regarding patient autonomy, substituted judgment, and nonimposition of physician values. However, students showed misunderstanding by giving doctors the responsibility of balancing the interests of the patient against the interests of the family, by stating doctors and surrogates should be guided primarily by a best-interest standard, and by suggesting that patient autonomy becomes the guiding principle only when patients can no longer express their wishes. Conclusion: Students did not appear to internalize or correctly apply the substituted judgment standard, even though they could describe it accurately. This suggests the substituted judgment standard may run counter to students ’ moral intuitions

    Hepatitis B virus infected physicians and disclosure of transmission risks to patients: A critical analysis

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    BACKGROUND: The potential for transmission of blood-borne pathogens such as hepatitis B virus from infected healthcare workers to patients is an important and difficult issue facing healthcare policymakers internationally. Law and policy on the subject is still in its infancy, and subject to a great degree of uncertainty and controversy. Policymakers have made few recommendations regarding the specifics of practice restriction for health care workers who are hepatitis B seropositive. Generally, they have deferred this work to vaguely defined "expert panels" which will have the power to dictate the conditions under which infected health care workers may continue to practice. DISCUSSION: In this paper we use recent Canadian policy statements as a critical departure point to propose more specific recommendations regarding disclosure of transmission risks in a way that minimizes practice restriction of hepatitis B seropositive health care workers without compromising patient safety. The range of arguments proposed in the literature are critically examined from the perspective of ethical analysis. SUMMARY: A process for considering the ethical implications of the disclosure of the sero-status of health care workers is advanced that considers the varied perspectives of different stakeholders

    Intensive medical student involvement in short-term surgical trips provides safe and effective patient care: a case review

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    <p>Abstract</p> <p>Background</p> <p>The hierarchical nature of medical education has been thought necessary for the safe care of patients. In this setting, medical students in particular have limited opportunities for experiential learning. We report on a student-faculty collaboration that has successfully operated an annual, short-term surgical intervention in Haiti for the last three years. Medical students were responsible for logistics and were overseen by faculty members for patient care. Substantial planning with local partners ensured that trip activities supplemented existing surgical services. A case review was performed hypothesizing that such trips could provide effective surgical care while also providing a suitable educational experience.</p> <p>Findings</p> <p>Over three week-long trips, 64 cases were performed without any reported complications, and no immediate perioperative morbidity or mortality. A plurality of cases were complex urological procedures that required surgical skills that were locally unavailable (43%). Surgical productivity was twice that of comparable peer institutions in the region. Student roles in patient care were greatly expanded in comparison to those at U.S. academic medical centers and appropriate supervision was maintained.</p> <p>Discussion</p> <p>This demonstration project suggests that a properly designed surgical trip model can effectively balance the surgical needs of the community with an opportunity to expose young trainees to a clinical and cross-cultural experience rarely provided at this early stage of medical education. Few formalized programs currently exist although the experience above suggests the rewarding potential for broad-based adoption.</p

    A tiered-layered-staged model for informed consent in personal genome testing

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    In recent years, developments in genomics technologies have led to the rise of commercial personal genome testing (PGT): broad genome-wide testing for multiple diseases simultaneously. While some commercial providers require physicians to order a personal genome test, others can be accessed directly. All providers advertise directly to consumers and offer genetic risk information about dozens of diseases in one single purchase. The quantity and the complexity of risk information pose challenges to adequate pre-test and post-test information provision and informed consent. There are currently no guidelines for what should constitute informed consent in PGT or how adequate informed consent can be achieved. In this paper, we propose a tiered-layered-staged model for informed consent. First, the proposed model is tiered as it offers choices between categories of diseases that are associated with distinct ethical, personal or societal issues. Second, the model distinguishes layers of information with a first layer offering minimal, indispensable information that is material to all consumers, and additional layers offering more detailed information made available upon request. Finally, the model stages informed consent as a process by feeding information to consumers in each subsequent stage of the process of undergoing a test, and by accommodating renewed consent for test result updates, resulting from the ongoing development of the science underlying PGT. A tiered-layered-staged model for informed consent with a focus on the consumer perspective can help overcome the ethical problems of information provision and informed consent in direct-to-consumer PGT.European Journal of Human Genetics advance online publication, 21 November 2012; doi:10.1038/ejhg.2012.237

    An Estimate of Avian Mortality at Communication Towers in the United States and Canada

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    Avian mortality at communication towers in the continental United States and Canada is an issue of pressing conservation concern. Previous estimates of this mortality have been based on limited data and have not included Canada. We compiled a database of communication towers in the continental United States and Canada and estimated avian mortality by tower with a regression relating avian mortality to tower height. This equation was derived from 38 tower studies for which mortality data were available and corrected for sampling effort, search efficiency, and scavenging where appropriate. Although most studies document mortality at guyed towers with steady-burning lights, we accounted for lower mortality at towers without guy wires or steady-burning lights by adjusting estimates based on published studies. The resulting estimate of mortality at towers is 6.8 million birds per year in the United States and Canada. Bootstrapped subsampling indicated that the regression was robust to the choice of studies included and a comparison of multiple regression models showed that incorporating sampling, scavenging, and search efficiency adjustments improved model fit. Estimating total avian mortality is only a first step in developing an assessment of the biological significance of mortality at communication towers for individual species or groups of species. Nevertheless, our estimate can be used to evaluate this source of mortality, develop subsequent per-species mortality estimates, and motivate policy action

    The mechanisms of humic substances self-assembly with biological molecules: The case study of the prion protein

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    Humic substances (HS) are the largest constituent of soil organic matter and are considered as a key component of the terrestrial ecosystem. HS may facilitate the transport of organic and inorganic molecules, as well as the sorption interactions with environmentally relevant proteins such as prions. Prions enter the environment through shedding from live hosts, facilitating a sustained incidence of animal prion diseases such as Chronic Wasting Disease and scrapie in cervid and ovine populations, respectively. Changes in prion structure upon environmental exposure may be significant as they can affect prion infectivity and disease pathology. Despite its relevance, the mechanisms of prion interaction with HS are still not completely understood. The goal of this work is to advance a structural-level picture of the encapsulation of recombinant, non-infectious, prion protein (PrP) into different natural HS. We observed that PrP precipitation upon addition of HS is mainly driven by a mechanism of “salting-out” whereby PrP molecules are rapidly removed from the solution and aggregate in insoluble adducts with humic molecules. Importantly, this process does not alter the protein folding since insoluble PrP retains its α-helical content when in complex with HS. The observed ability of HS to promote PrP insolubilization without altering its secondary structure may have potential relevance in the context of “prion ecology”. These results suggest that soil organic matter interacts with prions possibly without altering the protein structures. This may facilitate prions preservation from biotic and abiotic degradation leading to their accumulation in the environment
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