834 research outputs found

    Cardiac testing for coronary artery disease in potential kidney transplant recipients.

    Get PDF
    Patients with chronic kidney disease (CKD) are at increased risk of coronary artery disease (CAD) and adverse cardiac events. Screening for CAD is therefore an important part of preoperative evaluation for kidney transplant candidates. There is significant interest in the role of non-invasive cardiac investigations and their ability to identify patients at high risk of CAD.  We investigated the accuracy of non-invasive cardiac screening tests compared with coronary angiography to detect CAD in patients who are potential kidney transplant recipients. MEDLINE and EMBASE searches (inception to November 2010) were performed to identify studies that assessed the diagnostic accuracy of non-invasive screening tests, using coronary angiography as the reference standard. We also conducted citation tracking via Web of Science and handsearched reference lists of identified primary studies and review articles.   We included in this review all diagnostic cross sectional, cohort and randomised studies of test accuracy that compared the results of any cardiac test with coronary angiography (the reference standard) relating to patients considered as potential candidates for kidney transplantation or kidney-pancreas transplantation at the time diagnostic tests were performed.  We used a hierarchical modelling strategy to produce summary receiver operating characteristic (SROC) curves, and pooled estimates of sensitivity and specificity. Sensitivity analyses to determine test accuracy were performed if only studies that had full verification or applied a threshold of ≥ 70% stenosis on coronary angiography for the diagnosis of significant CAD were included. The following screening investigations included in the meta-analysis were: dobutamine stress echocardiography (DSE) (13 studies), myocardial perfusion scintigraphy (MPS) (nine studies), echocardiography (three studies), exercise stress electrocardiography (two studies), resting electrocardiography (three studies), and one study each of electron beam computed tomography (EBCT), exercise ventriculography, carotid intimal media thickness (CIMT) and digital subtraction fluorography (DSF). Sufficient studies were present to allow hierarchical summary receiver operating characteristic (HSROC) analysis for DSE and MPS. When including all available studies, both DSE and MPS had moderate sensitivity and specificity in detecting coronary artery stenosis in patients who are kidney transplant candidates [DSE (13 studies) - pooled sensitivity 0.79 (95% CI 0.67 to 0.88), pooled specificity 0.89 (95% CI 0.81 to 0.94); MPS (nine studies) - pooled sensitivity 0.74 (95% CI 0.54 to 0.87), pooled specificity 0.70 (95% CI 0.51 to 0.84)]. When limiting to studies which defined coronary artery stenosis using a reference threshold of ≥ 70% stenosis on coronary angiography, there was little change in these pooled estimates of accuracy [DSE (9 studies) - pooled sensitivity 0.76 (95% CI 0.60 to 0.87), specificity 0.88 (95% CI 0.78 to 0.94); MPS (7 studies) - pooled sensitivity 0.67 (95% CI 0.48 to 0.82), pooled specificity 0.77 (95% CI 0.61 to 0.88)]. There was evidence that DSE had improved accuracy over MPS (P = 0.02) when all studies were included in the analysis, but this was not significant when we excluded studies which did not avoid partial verification or use a reference standard threshold of ≥70% stenosis (P = 0.09).   DSE may perform better than MPS but additional studies directly comparing these cardiac screening tests are needed. Absence of significant CAD may not necessarily correlate with cardiac-event free survival following transplantation. Further research should focus on assessing the ability of functional tests to predict postoperative outcome

    A proposal for selective resuscitation of adult cardiac arrest patients in a pandemic

    Full text link
    Allocation of limited resources in pandemics begs for ethical guidance. The issue of ventilator allocation in pandemics has been reviewed by many medical ethicists, but as localities activate crisis standards of care, and health care workers are infected from patient exposure, the decision to pursue cardiopulmonary resuscitation (CPR) must also be examined to better balance the increased risks to healthcare personnel with the very low resuscitation rates of patients infected with coronavirus disease 2019 (COVID‐19). A crisis standard of care that is equitable, transparent, and mindful of both human and physical resources will lessen the impact on society in this era of COVID‐19. This paper builds on previous work of ventilator allocation in pandemic crises to propose a literature‐based, justice‐informed ethical framework for selecting treatment options for CPR. The pandemic affects regions differently over time, so these suggested guidelines may require adaptation to local practice variations.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/156457/3/emp212096_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156457/2/emp212096.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156457/1/emp212096-sup-0001-Appendix.pd

    Systematic review and meta-analysis of the diagnostic accuracy of ultrasonography for deep vein thrombosis

    Get PDF
    Background Ultrasound (US) has largely replaced contrast venography as the definitive diagnostic test for deep vein thrombosis (DVT). We aimed to derive a definitive estimate of the diagnostic accuracy of US for clinically suspected DVT and identify study-level factors that might predict accuracy. Methods We undertook a systematic review, meta-analysis and meta-regression of diagnostic cohort studies that compared US to contrast venography in patients with suspected DVT. We searched Medline, EMBASE, CINAHL, Web of Science, Cochrane Database of Systematic Reviews, Cochrane Controlled Trials Register, Database of Reviews of Effectiveness, the ACP Journal Club, and citation lists (1966 to April 2004). Random effects meta-analysis was used to derive pooled estimates of sensitivity and specificity. Random effects meta-regression was used to identify study-level covariates that predicted diagnostic performance. Results We identified 100 cohorts comparing US to venography in patients with suspected DVT. Overall sensitivity for proximal DVT (95% confidence interval) was 94.2% (93.2 to 95.0), for distal DVT was 63.5% (59.8 to 67.0), and specificity was 93.8% (93.1 to 94.4). Duplex US had pooled sensitivity of 96.5% (95.1 to 97.6) for proximal DVT, 71.2% (64.6 to 77.2) for distal DVT and specificity of 94.0% (92.8 to 95.1). Triplex US had pooled sensitivity of 96.4% (94.4 to 97.1%) for proximal DVT, 75.2% (67.7 to 81.6) for distal DVT and specificity of 94.3% (92.5 to 95.8). Compression US alone had pooled sensitivity of 93.8 % (92.0 to 95.3%) for proximal DVT, 56.8% (49.0 to 66.4) for distal DVT and specificity of 97.8% (97.0 to 98.4). Sensitivity was higher in more recently published studies and in cohorts with higher prevalence of DVT and more proximal DVT, and was lower in cohorts that reported interpretation by a radiologist. Specificity was higher in cohorts that excluded patients with previous DVT. No studies were identified that compared repeat US to venography in all patients. Repeat US appears to have a positive yield of 1.3%, with 89% of these being confirmed by venography. Conclusion Combined colour-doppler US techniques have optimal sensitivity, while compression US has optimal specificity for DVT. However, all estimates are subject to substantial unexplained heterogeneity. The role of repeat scanning is very uncertain and based upon limited data

    Evolutionary connectionism: algorithmic principles underlying the evolution of biological organisation in evo-devo, evo-eco and evolutionary transitions

    Get PDF
    The mechanisms of variation, selection and inheritance, on which evolution by natural selection depends, are not fixed over evolutionary time. Current evolutionary biology is increasingly focussed on understanding how the evolution of developmental organisations modifies the distribution of phenotypic variation, the evolution of ecological relationships modifies the selective environment, and the evolution of reproductive relationships modifies the heritability of the evolutionary unit. The major transitions in evolution, in particular, involve radical changes in developmental, ecological and reproductive organisations that instantiate variation, selection and inheritance at a higher level of biological organisation. However, current evolutionary theory is poorly equipped to describe how these organisations change over evolutionary time and especially how that results in adaptive complexes at successive scales of organisation (the key problem is that evolution is self-referential, i.e. the products of evolution change the parameters of the evolutionary process). Here we first reinterpret the central open questions in these domains from a perspective that emphasises the common underlying themes. We then synthesise the findings from a developing body of work that is building a new theoretical approach to these questions by converting well-understood theory and results from models of cognitive learning. Specifically, connectionist models of memory and learning demonstrate how simple incremental mechanisms, adjusting the relationships between individually-simple components, can produce organisations that exhibit complex system-level behaviours and improve the adaptive capabilities of the system. We use the term “evolutionary connectionism” to recognise that, by functionally equivalent processes, natural selection acting on the relationships within and between evolutionary entities can result in organisations that produce complex system-level behaviours in evolutionary systems and modify the adaptive capabilities of natural selection over time. We review the evidence supporting the functional equivalences between the domains of learning and of evolution, and discuss the potential for this to resolve conceptual problems in our understanding of the evolution of developmental, ecological and reproductive organisations and, in particular, the major evolutionary transitions

    How a Diverse Research Ecosystem Has Generated New Rehabilitation Technologies: Review of NIDILRR’s Rehabilitation Engineering Research Centers

    Get PDF
    Over 50 million United States citizens (1 in 6 people in the US) have a developmental, acquired, or degenerative disability. The average US citizen can expect to live 20% of his or her life with a disability. Rehabilitation technologies play a major role in improving the quality of life for people with a disability, yet widespread and highly challenging needs remain. Within the US, a major effort aimed at the creation and evaluation of rehabilitation technology has been the Rehabilitation Engineering Research Centers (RERCs) sponsored by the National Institute on Disability, Independent Living, and Rehabilitation Research. As envisioned at their conception by a panel of the National Academy of Science in 1970, these centers were intended to take a “total approach to rehabilitation”, combining medicine, engineering, and related science, to improve the quality of life of individuals with a disability. Here, we review the scope, achievements, and ongoing projects of an unbiased sample of 19 currently active or recently terminated RERCs. Specifically, for each center, we briefly explain the needs it targets, summarize key historical advances, identify emerging innovations, and consider future directions. Our assessment from this review is that the RERC program indeed involves a multidisciplinary approach, with 36 professional fields involved, although 70% of research and development staff are in engineering fields, 23% in clinical fields, and only 7% in basic science fields; significantly, 11% of the professional staff have a disability related to their research. We observe that the RERC program has substantially diversified the scope of its work since the 1970’s, addressing more types of disabilities using more technologies, and, in particular, often now focusing on information technologies. RERC work also now often views users as integrated into an interdependent society through technologies that both people with and without disabilities co-use (such as the internet, wireless communication, and architecture). In addition, RERC research has evolved to view users as able at improving outcomes through learning, exercise, and plasticity (rather than being static), which can be optimally timed. We provide examples of rehabilitation technology innovation produced by the RERCs that illustrate this increasingly diversifying scope and evolving perspective. We conclude by discussing growth opportunities and possible future directions of the RERC program

    Turnip yellow mosaic virus in Chinese cabbage in Spain: Commercial seed transmission and molecular characterization

    Full text link
    [EN] Seed transmission of Turnip yellow mosaic virus (TYMV, genus Tymovirus) was evaluated in the whole seeds and seedlings that emerged from three commercial Chinese cabbage (Brassica pekinensis) seed batches. Seedlings in the cotyledon stage and adult plants were assayed for TYMV by DAS-ELISA and confirmed by RT-PCR. The proportion of whole seeds infected with TYMV was at least 0.15 %. The seeds of the three seed batches were grown in Petri dishes, and surveyed in the cotyledon stage in trays that contained a peat:sand mixture grown in greenhouses or growth chambers, which were analysed in the cotyledon and adult stages. The seed-to-seedling transmission rate ranged from 2.5 % to 2.9 % in two different seed batches (lot-08 and lot-09, respectively). Spanish isolates derived from turnip (Sp-03) and Chinese cabbage (Sp-09 and Sp-13), collected in 2003, 2009 and 2013 in two different Spanish regions, were molecularly characterised by analysing the partial nucleotide sequences of three TYMV genome regions: partial RNA-dependent RNA polymerase (RdRp), methyltransferase (MTR) and coat protein (CP) genes. Phylogenetic analyses showed that the CP gene represented two different groups: TYMV-1 and TYMV-2. The first was subdivided into three subclades: European, Australian and Japanese. Spanish isolate Sp-03 clustered together with European TYMV group, whereas Sp-09 and Sp-13 grouped with the Japanese TYMV group, and all differed from group TYMV-2. The sequences of the three different genomic regions examined clustered into the same groups. The results suggested that Spanish isolates grouped according to the original hosts from which they were isolated. The inoculation of the Spanish TYMV isolates to four crucifer plants species (turnip, broccoli, Brunswick cabbage and radish) revealed that all the isolates infected turnip with typical symptoms, although differences were observed in other hosts.Alfaro Fernández, AO.; Serrano, A.; Tornos, T.; Cebrian Mico, MC.; Córdoba-Sellés, MDC.; Jordá, C.; Font San Ambrosio, MI. (2016). Turnip yellow mosaic virus in Chinese cabbage in Spain: Commercial seed transmission and molecular characterization. EUROPEAN JOURNAL OF PLANT PATHOLOGY. 146(2):433-442. doi:10.1007/s10658-016-0929-3S4334421462Assis Filho, M., & Sherwood, J. L. (2000). Evaluation of seed transmission of Turnip yellow mosaic virus and Tobacco mosaic virus in Arabidopsis thaliana. Phytopathology, 90, 1233–1238.Benetti, M. P., & Kaswalder, F. (1983). Trasmisione per seme del virus del mosaico giallo rapa. Annali dell Istituto Sperimentale per la Patologia Vegetale, 8, 67–70.Blok, J., Mackenzie, A., Guy, P., & Gibbs, A. (1987). Nucleotide sequence comparisons of Turnip yellow mosaic virus isolates from Australia and Europe. Archives of Virology, 97, 283–295.Brunt, A., Crabtree, K., Dallwitz, M., Gibbs, A., Watson, L., & Zurcher, E.J. (1996). Plant Viruses Online: Descriptions and Lists from the VIDE Database. Version: 20th August 1996. URL http://biology.anu.edu.au/Groups/MES/vide/ .Campbell, R. N., Wipf-Scheibel, C., & Lecoq, H. (1996). Vector-assissted seed transmission of melon necrotic spot virus in melon. Phytopathology, 86, 1294–1298.Dreher, T. W., & Bransom, K. L. (1992). Genomic RNA sequence of Turnip yellow mosaic virus isolate TYMC, a cDNA-based clone with verified infectivity. Plant Molecular Biology, 18, 403–406.Fakhro, A., Von Bargen, S., Bandte, M., Büttner, C., Franken, P., & Schwarz, D. (2011). Susceptibility of different plant species and tomato cultivars to two isolates of Pepino mosaic virus. European Journal of Plant Pathology, 129, 579–590.Gibbs, A. J., & Gower, J. C. (1960). The use of a multiple-transfer method in plant virus transmission studies: some statistical points arising in the analysis of results. Annals of Applied Biology, 48, 75–83.Hayden, C. M., Mackenzie, A. M., & Gibbs, A. J. (1998a). Virion protein sequence variation among Australian isolates of turnip yellow mosaic tymovirus. Archives of Virology, 143, 191–201.Hayden, C. M., Mackenzie, A. M., Skotnicki, M. L., & Gibbs, A. (1998b). Turnip yellow mosaic virus isolates with experimentally produced recombinant virion proteins. Journal of General Virology, 79, 395–403.Hein, A. (1984). Transmission of Turnip yellow mosaic virus through seed of Camelina sativa gold of pleasure. Journal of Plant Diseases and Protection, 91, 549–551.Herrera-Vásquez, J. A., Córdoba-Sellés, M. C., Cebrián, M. C., Alfaro-Fernández, A., & Jordá, C. (2009). Seed transmission of Melon necrotic spot virus and efficacy of seed-disinfection treatments. Plant Pathology, 58, 436–452.Hull, R. (2002). Matthews’ plant virology (4a ed.1001 pp). San Diego: Academic Press.Johansen, E., Edwards, M. C., & Hampton, R. O. (1994). Seed transmission of viruses: current perspectives. Annual Review of Phytopathology, 32, 363–386.Kirino, N., Inoue, K., Tanina, K., Yamazaki, Y., & Ohki, S. T. (2008). Turnip yellow mosaic virus isolated from Chinese cabbage in Japan. Journal of General Plant Pathology, 74, 331–334.Markham, R., & Smith, K. S. (1949). Studies on the virus of turnip yellow mosaic. Parasitology, 39, 330–342.Mathews, R. E. F. (1980). Turnip yellow mosaic virus, CMI/AAB Descriptions of plant virus No. 230 (No. 2 revised). Kew: Commonwealth Mycology Institute/Association of Applied Biologists.Mitchell, E. J., & Bond, J. M. (2005). Variation in the coat protein sequence of British isolates of Turnip yellow mosaic virus and comparison with previously published isolates. Archives of Virology, 150, 2347–2355.Pagán, I., Fraile, A., Fernández-Fueyo, E., Montes, N., Alonso-Blanco, C., & García-Arenal, F. (2010). Arabidopsis thaliana as a model for the study of plant-virus co-evolution. Philosophical Transations of the Royal Society Biological Sciences, 365, 1983–1995.Paul, H. L., Gibbs, A., & Wittman-Liebold, B. (1980). The relationships of certain Tymoviruses assessed from the amino acid composition of their coat proteins. Intervirology, 13, 99–109.Pelikanova, J. (1990). Garlic mustard a spontaneous host of TYMV. Ochrana Rostlin, 26, 17–22.Procházková, Z. (1980). Host range and symptom differences between isolates of Turnip mosaic virus obtained from Sisymbrium loeselii. Biologia Plantarum, 22, 341–347.Rimmer, S. R., Shtattuck, V. I., & Buchwaldt, L. (2007). Compendium of brassica diseases (1ª Edición ed.p. 117). USA: APS press.Rot, M. E., & Jelkman, W. (2001). Characterization and detection of several filamentous viruses of cherry: Adaptation of an alternative cloning method (DOP-PCR), and modification of an RNA extraction protocol. European Journal of Plant Pathology, 107, 411–420.Sabanadzovic, S., Abou-Ghanem, N., Castellano, M. A., Digiaero, M., & Martelli, G. P. (2000). Grapevine fleck virus-like in Vitis. Archives of Virology, 145, 553–565.Špack, J., & Kubelková, D. (2000). Serological variability among European isolates of Radish mosaic virus. Plant Pathology, 49, 295–301.Špack, J., Kubelková, D., & Hnilicka, E. (1993). Seed transmission of Turnip yellow mosaic virus in winter turnip and winter oilseed rapes. Annals of Applied Biology, 123, 33–35.Stobbs, L. W., Cerkauskas, R. F., Lowery, T., & VanDriel, L. (1998). Occurrence of Turnip yellow mosaic virus on oriental cruciferours vegetables in Southern Ontario, Canada. Plant Disease, 82, 351.Tamura, K., Peterson, D., Peterson, N., Stecher, G., Nei, M., & Kumar, S. (2011). MEGA5: molecular evolutionary genetics analysis using maximum likelihood, evolutionary distance, and maximum parsimony methods. Molecular Biology and Evolution, 28, 2731–2739

    Evidence for Escherichia coli DcuD carrier dependent FOF1-ATPase activity during fermentation of glycerol

    Get PDF
    During fermentation Escherichia coli excrete succinate mainly via Dcu family carriers. Current work reveals the total and N,N’-dicyclohexylcarbodiimide (DCCD) inhibited ATPase activity at pH 7.5 and 5.5 in E. coli wild type and dcu mutants upon glycerol fermentation. The overall ATPase activity was highest at pH 7.5 in dcuABCD mutant. In wild type cells 50% of the activity came from the FOF1-ATPase but in dcuD mutant it reached ~80%. K+ (100 mM) stimulate total but not DCCD inhibited ATPase activity 40% and 20% in wild type and dcuD mutant, respectively. 90% of overall ATPase activity was inhibited by DCCD at pH 5.5 only in dcuABC mutant. At pH 7.5 the H+ fluxes in E. coli wild type, dcuD and dcuABCD mutants was similar but in dcuABC triple mutant the H+ flux decreased 1.4 fold reaching 1.15 mM/min when glycerol was supplemented. In succinate assays the H+ flux was higher in the strains where DcuD is absent. No significant differences were determined in wild type and mutants specific growth rate except dcuD strain. Taken together it is suggested that during glycerol fermentation DcuD has impact on H+ fluxes, FOF1-ATPase activity and depends on potassium ions

    Psychometric properties of instruments to measure the quality of end-of-life care and dying for long-term care residents with dementia

    Get PDF
    Purpose: Quality of care for long-term care (LTC) residents with dementia at the end-of-life is often evaluated using standardized instruments that were not developed for or thoroughly tested in this population. Given the importance of using appropriate instruments to evaluate the quality of care (QOC) and quality of dying (QOD) in LTC, we compared the validity and reliability of ten available instruments commonly used for these purposes. Methods: We performed prospective observations and retrospective interviews and surveys of family (n = 70) and professionals (n = 103) of LTC decedents with dementia in the Netherlands. Results: Instruments within the constructs QOC and QOD were highly correlated, and showed moderate to high correlation with overall assessments of QOC and QOD. Prospective and retrospective ratings using the same instruments differed little. Concordance between family and professional scores was low. Cronbach's alpha was mostly adequate. The EOLD-CAD showed good fit with pre-assumed factor structures. The EOLD-SWC and FPCS appear most valid and reliable for measuring QOC, and the EOLD-CAD and MSSE for measuring QOD. The POS performed worst in this population. Conclusions: Our comparative study of psychometric properties of instruments allows for informed selection of QOC and QOD measures for LTC residents with dementia. © The Author(s) 2011

    Establishing an implementation network: lessons learned from community-based participatory research

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Implementation of evidence-based mental health assessment and intervention in community public health practice is a high priority for multiple stakeholders. Academic-community partnerships can assist in the implementation of efficacious treatments in community settings; yet, little is known about the processes by which these collaborations are developed. In this paper, we discuss our application of community-based participatory research (CBPR) approach to implementation, and we present six lessons we have learned from the establishment of an academic-community partnership.</p> <p>Methods</p> <p>With older adults with psychosis as a focus, we have developed a partnership between a university research center and a public mental health service system based on CBPR. The long-term goal of the partnership is to collaboratively establish an evidence-based implementation network that is sustainable within the public mental healthcare system.</p> <p>Results</p> <p>In building a sustainable partnership, we found that the following lessons were instrumental: changing attitudes; sharing staff; expecting obstacles and formalizing solutions; monitoring and evaluating; adapting and adjusting; and taking advantage of emerging opportunities. Some of these lessons were previously known principles that were modified as the result of the CBPR process, while some lessons derived directly from the interactive process of forming the partnership.</p> <p>Conclusion</p> <p>The process of forming of academic-public partnerships is challenging and time consuming, yet crucial for the development and implementation of state-of-the-art approaches to assessment and interventions to improve the functioning and quality of life for persons with serious mental illnesses. These partnerships provide necessary organizational support to facilitate the implementation of clinical research findings in community practice benefiting consumers, researchers, and providers.</p
    corecore