396 research outputs found

    The pacing stress test: Thallium-201 myocardial imaging after atrial pacing. Diagnostic value in detecting coronary artery disease compared with exercise testing

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    Many patients suspected of having coronary artery disease are unable to undergo adequate exercise testing. An alternate stress, pacing tachycardia, has been shown to produce electrocardiographic changes that are as sensitive and specific as those observed during exercise testing. To compare thallium-201 imaging after atrial pacing stress with thallium imaging after exercise stress, 22 patients undergoing cardiac catheterization were studied with both standard exercise thallium imaging and pacing thallium imaging.Positive ischemic electrocardiographic changes (> 1 mm ST segment depression) were noted in 11 of 16 patients with coronary artery disease during exercise, and in 15 of the 16 patients during atrial pacing. One of six patients with normal or trivial coronary artery disease had a positive electrocardiogram with each test. Exercise thallium imaging was positive in 13 of 16 patients with coronary artery disease compared with 15 of 16 patients during atrial pacing. Three of six patients without coronary artery disease had a positive scan with exercise testing, and two of these same patients developed a positive scan with atrial pacing. Of those patients with coronary artery disease and an abnormal scan, 85% showed redistribution with exercise testing compared with 87% during atrial pacing. Segment by segment comparison of thallium imaging after either atrial pacing or exercise showed that there was a good correlation of the location and severity of the thallium defects (r = 0.83, p = 0.0001, Spearman rank correlation).It is concluded that the location and presence of both fixed and transient thallium defects after atrial pacing are closely correlated with the findings after exercise testing. Thus, atrial pacing may be used as a stress for myocardial perfusion scintigraphy in patients unable to complete a satisfactory exercise test

    Sexual Transmission of XMRV: A Potential Infection Route

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    Although XMRV dissemination in humans is a matter of debate, the prostate of select patients seem to harbor XMRV, which raises questions about its potential route of transmission. We established a model of infection in rhesus macaques inoculated with XMRV. In spite of the intravenous inoculation, all infected macaques exhibited readily detectable XMRV signal in the reproductive tract of all 4 males and 1 female during both acute and chronic infection stages. XMRV showed explosive growth in the acini of prostate during acute but not chronic infection. In seminal vesicles, epididymis, and testes, XMRV protein production was detected throughout infection in interstitial or epithelial cells. In the female monkey, epithelial cells in the cervix and vagina were also positive for XMRV gag. The ready detection of XMRV in the reproductive tract of male and female macaques infected intravenously suggests the potential for sexual transmission for XMRV

    SN~2012cg: Evidence for Interaction Between a Normal Type Ia Supernova and a Non-Degenerate Binary Companion

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    We report evidence for excess blue light from the Type Ia supernova SN 2012cg at fifteen and sixteen days before maximum B-band brightness. The emission is consistent with predictions for the impact of the supernova on a non-degenerate binary companion. This is the first evidence for emission from a companion to a SN Ia. Sixteen days before maximum light, the B-V color of SN 2012cg is 0.2 mag bluer than for other normal SN~Ia. At later times, this supernova has a typical SN Ia light curve, with extinction-corrected M_B = -19.62 +/- 0.02 mag and Delta m_{15}(B) = 0.86 +/- 0.02. Our data set is extensive, with photometry in 7 filters from 5 independent sources. Early spectra also show the effects of blue light, and high-velocity features are observed at early times. Near maximum, the spectra are normal with a silicon velocity v_{Si} = -10,500$ km s^{-1}. Comparing the early data with models by Kasen (2010) favors a main-sequence companion of about 6 solar masses. It is possible that many other SN Ia have main-sequence companions that have eluded detection because the emission from the impact is fleeting and faint.Comment: accepted to Ap

    Correction of Aberrant Splicing of the Cystic Fibrosis Transmembrane Conductance Regulator ( CFTR ) Gene by Antisense Oligonucleotides

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    The CFTR splicing mutation 3849 + 10 kb C --> T creates a novel donor site 10 kilobases (kb) into intron 19 of the gene and is one of the more common splicing mutations that causes cystic fibrosis (CF). It has an elevated prevalence among patients with atypically mild disease and normal sweat electrolytes and is especially prominent in Ashkenazi Jews. This class of splicing mutations, reported in several genes, involves novel splice sites activated deep within introns while leaving wild-type splice elements intact. CFTR cDNA constructs that modeled the 3849 + 10 kb C --> T mutation were expressed in 3T3 mouse fibroblasts and in CFT1 human tracheal and C127 mouse mammary epithelial cells. In all three cell types, aberrant splicing of CFTR pre-mRNA was comparable to that reported in vivo in CF patients. Treatment of the cells with 2'-O-methyl phosphorothioate oligoribonucleotides antisense toward the aberrant donor and acceptor splice sites or to the retained exon-like sequence, disfavored aberrant splicing and enhanced normal processing of CFTR pre-mRNA. This antisense-mediated correction of splicing was dose- and sequence-dependent and was accompanied by increased production of CFTR protein that was appropriately glycosylated. Antisense-mediated correction of splicing in a mutation-specific context represents a potential gene therapy modality with applicability to many inherited disorders

    Object Relations in the Museum: A Psychosocial Perspective

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    This article theorises museum engagement from a psychosocial perspective. With the aid of selected concepts from object relations theory, it explains how the museum visitor can establish a personal relation to museum objects, making use of them as an ‘aesthetic third’ to symbolise experience. Since such objects are at the same time cultural resources, interacting with them helps the individual to feel part of a shared culture. The article elaborates an example drawn from a research project that aimed to make museum collections available to people with physical and mental health problems. It draws on the work of the British psychoanalysts Donald Winnicott and Wilfred Bion to explain the salience of the concepts of object use, potential space, containment and reverie within a museum context. It also refers to the work of the contemporary psychoanalyst Christopher Bollas on how objects can become evocative for individuals both by virtue of their intrinsic qualities and by the way they are used to express personal idiom

    Scope for Credit Risk Diversification

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    This paper considers a simple model of credit risk and derives the limit distribution of losses under different assumptions regarding the structure of systematic risk and the nature of exposure or firm heterogeneity. We derive fat-tailed correlated loss distributions arising from Gaussian risk factors and explore the potential for risk diversification. Where possible the results are generalised to non-Gaussian distributions. The theoretical results indicate that if the firm parameters are heterogeneous but come from a common distribution, for sufficiently large portfolios there is no scope for further risk reduction through active portfolio management. However, if the firm parameters come from different distributions, then further risk reduction is possible by changing the portfolio weights. In either case, neglecting parameter heterogeneity can lead to underestimation of expected losses. But, once expected losses are controlled for, neglecting parameter heterogeneity can lead to overestimation of risk, whether measured by unexpected loss or value-at-risk

    Ensuring due process in the IACUC and animal welfare setting: considerations in developing noncompliance policies and procedures for institutional animal care and use committees and institutional officials

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    Every institution that is involved in research with animals is expected to have in place policies and procedures for the management of allegations of noncompliance with the Animal Welfare Act and the U.S. Public Health Service Policy on the Humane Care and Use of Laboratory Animals. We present here a model set of recommendations for institutional animal care and use committees and institutional officials to ensure appropriate consideration of allegations of noncompliance with federal Animal Welfare Act regulations that carry a significant risk or specific threat to animal welfare. This guidance has 3 overarching aims: 1) protecting the welfare of research animals; 2) according fair treatment and due process to an individual accused of noncompliance; and 3) ensuring compliance with federal regulations. Through this guidance, the present work seeks to advance the cause of scientific integrity, animal welfare, and the public trust while recognizing and supporting the critical importance of animal research for the betterment of the health of both humans and animals.â Hansen, B. C., Gografe, S., Pritt, S., Jen, K.â L. C., McWhirter, C. A., Barman, S. M., Comuzzie, A., Greene, M., McNulty, J. A., Michele, D. E., Moaddab, N., Nelson, R. J., Norris, K., Uray, K. D., Banks, R., Westlund, K. N., Yates, B. J., Silverman, J., Hansen, K. D., Redman, B. Ensuring due process in the IACUC and animal welfare setting: considerations in developing noncompliance policies and procedures for institutional animal care and use committees and institutional officials. FASEB J. 31, 4216â 4225 (2017). www.fasebj.orgPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154293/1/fsb2fj201601250r.pd

    Measures of outcome for stimulant trials: ACTTION recommendations and research agenda

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    BACKGROUND: The development and approval of an efficacious pharmacotherapy for stimulant use disorders has been limited by the lack of a meaningful indicator of treatment success, other than sustained abstinence. METHODS: In March, 2015, a meeting sponsored by Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks (ACTTION) was convened to discuss the current state of the evidence regarding meaningful outcome measures in clinical trials for stimulant use disorders. Attendees included members of academia, funding and regulatory agencies, pharmaceutical companies, and healthcare organizations. The goal was to establish a research agenda for the development of a meaningful outcome measure that may be used as an endpoint in clinical trials for stimulant use disorders. RESULTS AND CONCLUSIONS: Based on guidelines for the selection of clinical trial endpoints, the lessons learned from prior addiction clinical trials, and the process that led to identification of a meaningful indicator of treatment success for alcohol use disorders, several recommendations for future research were generated. These include a focus on the validation of patient reported outcome measures of functioning, the exploration of patterns of stimulant abstinence that may be associated with physical and/or psychosocial benefits, the role of urine testing for validating self-reported measures of stimulant abstinence, and the operational definitions for reduction-based measures in terms of frequency rather than quantity of stimulant use. These recommendations may be useful for secondary analyses of clinical trial data, and in the design of future clinical trials that may help establish a meaningful indicator of treatment success

    The Global Longitudinal Study of Osteoporosis in Women (GLOW): rationale and study design

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    SUMMARY: The Global Longitudinal study of Osteoporosis in Women (GLOW) is a prospective cohort study involving 723 physicians and 60,393 women subjects \u3eor=55 years. The data will provide insights into the management of fracture risk in older women over 5 years, patient experience with prevention and treatment, and distribution of risk among older women on an international basis. INTRODUCTION: Data from cohort studies describing the distribution of osteoporosis-related fractures and risk factors are not directly comparable and do not compare regional differences in patterns of patient management and fracture outcomes. METHODS: The GLOW is a prospective, multinational, observational cohort study. Practices typical of each region were identified through primary care networks organized for administrative, research, or educational purposes. Noninstitutionalized patients visiting each practice within the previous 2 years were eligible. Self-administered questionnaires were mailed, with 2:1 oversampling of women \u3eor=65 years. Follow-up questionnaires will be sent at 12-month intervals for 5 years. RESULTS: A total of 723 physicians at 17 sites in ten countries agreed to participate. Baseline surveys were mailed (October 2006 to February 2008) to 140,416 subjects. After the exclusion of 3,265 women who were ineligible or had died, 60,393 agreed to participate. CONCLUSIONS: GLOW will provide contemporary information on patterns of management of fracture risk in older women over a 5-year period. The collection of data in a similar manner in ten countries will permit comparisons of patient experience with prevention and treatment and provide insights into the distribution of risk among older women on an international basis
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