302 research outputs found

    Apheresis as novel treatment for refractory angina with raised lipoprotein(a): a randomised controlled trial

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    Aims To determine the clinical impact of lipoprotein apheresis in patients with refractory angina and raised lipoprotein(a) > 500 mg/L on the primary end point of quantitative myocardial perfusion, as well as secondary end points including atheroma burden, exercise capacity, symptoms, and quality of life. Methods We conducted a single-blinded randomized controlled trial in 20 patients with refractory angina and raised lipoprotein(a) > 500 mg/L, with 3 months of blinded weekly lipoprotein apheresis or sham, followed by crossover. The primary endpoint was change in quantitative myocardial perfusion reserve (MPR) assessed by cardiovascular magnetic resonance. Secondary endpoints included measures of atheroma burden, exercise capacity, symptoms and quality of life. Results The primary endpoint, namely MPR, increased following apheresis (0.47; 95% CI 0.31–0.63) compared with sham (−0.16; 95% CI − 0.33–0.02) yielding a net treatment increase of 0.63 (95% CI 0.37–0.89; P < 0.001 between groups). Improvements with apheresis compared with sham also occurred in atherosclerotic burden as assessed by total carotid wall volume (P < 0.001), exercise capacity by the 6 min walk test (P = 0.001), 4 of 5 domains of the Seattle angina questionnaire (all P < 0.02) and quality of life physical component summary by the short form 36 survey (P = 0.001). Conclusion Lipoprotein apheresis may represent an effective novel treatment for patients with refractory angina and raised lipoprotein(a) improving myocardial perfusion, atheroma burden, exercise capacity and symptoms

    Micro-Raman study of crichtonite group minerals enclosed into mantle garnet

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    We report the first comprehensive micro-Raman study of crichtonite group minerals (CGM) as inclusions in pyropic garnet grains from peridotite and pyroxenite mantle xenoliths of the Yakutian kimberlites as well as in garnet xenocrysts from the Aldan shield lamprophyres (Russia). The CGM form (i) morphologically oriented needles, lamellae, and short prisms and (ii) optically unoriented subhedral to euhedral grains, either single or intergrown with other minerals. We considered common mantle-derived CGM species (like loveringite, lindsleyite, and their analogues), with Ca, Ba, or Sr dominating in the dodecahedral A site and Zr or Fe in the octahedral B site. The Raman bands at the region of 600–830 cm−1 are indicative of CGM and their crystal-chemical distinction, although the intensity and shape of the bands appear to be dependent on laser beam power and wavelength. The factor-group analysis based on the loveringite crystal structure showed the octahedral and tetrahedral cation groups with 18f and 6c Wyckoff positions, namely, dominantly TiO6 and to a lower extent CrO6, MgO4, and FeO4 groups, to be the major contributors to the Raman spectral features. The ionic groups with dodecahedral (M0) and octahedral (M1) coordination are inactive for Raman scattering while active in infrared absorption. A number of observed Raman modes in the CGM spectra are several times lower than that predicted by the factor group analysis. The noticed broadening of modes in the CGM Raman spectra may result from a combining of bands at the narrow frequency shift regions. Solid solution behavior, luminescence, and partial metamictization of the CGM may exert additional influence on the Raman band shape. The Raman spectral features showed CGM to be accurately identified and distinguished from other Ti-, Fe-, Cr-, and Zr-containing oxides (e.g., ilmenite or those of spinel and magnetoplumbite groups) occurring as accessory mantle minerals. © 2020 The Authors. Journal of Raman Spectroscopy published by John Wiley & Sons LtdRussian Science Foundation, RSF: 18‐77‐10062Council on grants of the President of the Russian FederationThis study was supported by the Russian Science Foundation (Grant 18‐77‐10062). The equipment of the Ural Center for Shared Use «Modern Nanotechnology», Ural Federal University, and the Analytical Center for Multi‐elemental and Isotope Research, IGM, was used. Sampling was supported by the Russian Federation state assignment project of IGM. We are grateful to Nikolai V. Sobolev for Samples O‐173, O‐39, and O‐264. Vladimir N. Korolyuk, Elena N. Nigmatulina (IGM), and Allan Patchen (UT) are highly appreciated for the help with EMP analyses. We express our sincere thanks to F. Nestola and an anonymous reviewer for their thorough reviews and helpful suggestions, and to C. Marshall for regardful editorial handling of the manuscript on every stage of its revision

    Sequence optimization to reduce velocity offsets in cardiovascular magnetic resonance volume flow quantification--a multi-vendor study.

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    PURPOSE: Eddy current induced velocity offsets are of concern for accuracy in cardiovascular magnetic resonance (CMR) volume flow quantification. However, currently known theoretical aspects of eddy current behavior have not led to effective guidelines for the optimization of flow quantification sequences. This study is aimed at identifying correlations between protocol parameters and the resulting velocity error in clinical CMR flow measurements in a multi-vendor study. METHODS: Nine 1.5T scanners of three different types/vendors were studied. Measurements were performed on a large stationary phantom. Starting from a clinical breath-hold flow protocol, several protocol parameters were varied. Acquisitions were made in three clinically relevant orientations. Additionally, a time delay between the bipolar gradient and read-out, asymmetric versus symmetric velocity encoding, and gradient amplitude and slew rate were studied in adapted sequences as exploratory measurements beyond the protocol. Image analysis determined the worst-case offset for a typical great-vessel flow measurement. RESULTS: The results showed a great variation in offset behavior among scanners (standard deviation among samples of 0.3, 0.4, and 0.9 cm/s for the three different scanner types), even for small changes in the protocol. Considering the absolute values, none of the tested protocol settings consistently reduced the velocity offsets below the critical level of 0.6 cm/s neither for all three orientations nor for all three scanner types. Using multilevel linear model analysis, oblique aortic and pulmonary slices showed systematic higher offsets than the transverse aortic slices (oblique aortic 0.6 cm/s, and pulmonary 1.8 cm/s higher than transverse aortic). The exploratory measurements beyond the protocol yielded some new leads for further sequence development towards reduction of velocity offsets; however those protocols were not always compatible with the time-constraints of breath-hold imaging and flow-related artefacts. CONCLUSIONS: This study showed that with current systems there was no generic protocol which resulted into acceptable flow offset values. Protocol optimization would have to be performed on a per scanner and per protocol basis. Proper optimization might make accurate (transverse) aortic flow quantification possible for most scanners. Pulmonary flow quantification would still need further (offline) correction.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

    Comparison of the benefits of cochlear implantation versus contra-lateral routing of signal hearing aids in adult patients with single-sided deafness: study protocol for a prospective within-subject longitudinal trial

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    Background Individuals with a unilateral severe-to-profound hearing loss, or single-sided deafness, report difficulty with listening in many everyday situations despite having access to well-preserved acoustic hearing in one ear. The standard of care for single-sided deafness available on the UK National Health Service is a contra-lateral routing of signals hearing aid which transfers sounds from the impaired ear to the non-impaired ear. This hearing aid has been found to improve speech understanding in noise when the signal-to-noise ratio is more favourable at the impaired ear than the non-impaired ear. However, the indiscriminate routing of signals to a single ear can have detrimental effects when interfering sounds are located on the side of the impaired ear. Recent published evidence has suggested that cochlear implantation in individuals with a single-sided deafness can restore access to the binaural cues which underpin the ability to localise sounds and segregate speech from other interfering sounds. Methods/Design The current trial was designed to assess the efficacy of cochlear implantation compared to a contra-lateral routing of signals hearing aid in restoring binaural hearing in adults with acquired single-sided deafness. Patients are assessed at baseline and after receiving a contra-lateral routing of signals hearing aid. A cochlear implant is then provided to those patients who do not receive sufficient benefit from the hearing aid. This within-subject longitudinal design reflects the expected care pathway should cochlear implantation be provided for single-sided deafness on the UK National Health Service. The primary endpoints are measures of binaural hearing at baseline, after provision of a contra-lateral routing of signals hearing aid, and after cochlear implantation. Binaural hearing is assessed in terms of the accuracy with which sounds are localised and speech is perceived in background noise. The trial is also designed to measure the impact of the interventions on hearing- and health-related quality of life. Discussion This multi-centre trial was designed to provide evidence for the efficacy of cochlear implantation compared to the contra-lateral routing of signals. A purpose-built sound presentation system and established measurement techniques will provide reliable and precise measures of binaural hearing. Trial registration Current Controlled Trials http://www.controlled-trials.com/ISRCTN33301739 (05/JUL/2013

    A Naturally Occurring Plant Cysteine Protease Possesses Remarkable Toxicity against Insect Pests and Synergizes Bacillus thuringiensis Toxin

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    When caterpillars feed on maize (Zea maize L.) lines with native resistance to several Lepidopteran pests, a defensive cysteine protease, Mir1-CP, rapidly accumulates at the wound site. Mir1-CP has been shown to inhibit caterpillar growth in vivo by attacking and permeabilizing the insect's peritrophic matrix (PM), a structure that surrounds the food bolus, assists in digestion and protects the midgut from microbes and toxins. PM permeabilization weakens the caterpillar defenses by facilitating the movement of other insecticidal proteins in the diet to the midgut microvilli and thereby enhancing their toxicity. To directly determine the toxicity of Mir1-CP, the purified recombinant enzyme was directly tested against four economically significant Lepidopteran pests in bioassays. Mir1-CP LC50 values were 1.8, 3.6, 0.6, and 8.0 ppm for corn earworm, tobacco budworm, fall armyworm and southwestern corn borer, respectively. These values were the same order of magnitude as those determined for the Bacillus thuringiensis toxin Bt-CryIIA. In addition to being directly toxic to the larvae, 60 ppb Mir1-CP synergized sublethal concentrations of Bt-CryIIA in all four species. Permeabilization of the PM by Mir1-CP probably provides ready access to Bt-binding sites on the midgut microvilli and increases its activity. Consequently, Mir1-CP could be used for controlling caterpillar pests in maize using non-transgenic approaches and potentially could be used in other crops either singly or in combination with Bt-toxins

    Assignment of the gene for cytosolic alanine aminotransferase (AAT1) to human chromosome 8

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    The segregation of human cytosolic alanine aminotransferase (AAT1) and the individual human chromosomes has been studied in 27 secondary and tertiary rat hepatoma-human (liver) fibroblast hybrids. The staining solution used to visualize AAT activity on starch gels was specific for AAT since it was visualized only when all components of the stain were present. The locus for human AAT1 has been assigned to chromosome 8

    Quantification and visualization of cardiovascular 4D velocity mapping accelerated with parallel imaging or k-t BLAST: head to head comparison and validation at 1.5 T and 3 T

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    <p>Abstract</p> <p>Background</p> <p>Three-dimensional time-resolved (4D) phase-contrast (PC) CMR can visualize and quantify cardiovascular flow but is hampered by long acquisition times. Acceleration with SENSE or k-t BLAST are two possibilities but results on validation are lacking, especially at 3 T. The aim of this study was therefore to validate quantitative in vivo cardiac 4D-acquisitions accelerated with parallel imaging and k-t BLAST at 1.5 T and 3 T with 2D-flow as the reference and to investigate if field strengths and type of acceleration have major effects on intracardiac flow visualization.</p> <p>Methods</p> <p>The local ethical committee approved the study. 13 healthy volunteers were scanned at both 1.5 T and 3 T in random order with 2D-flow of the aorta and main pulmonary artery and two 4D-flow sequences of the heart accelerated with SENSE and k-t BLAST respectively. 2D-image planes were reconstructed at the aortic and pulmonary outflow. Flow curves were calculated and peak flows and stroke volumes (SV) compared to the results from 2D-flow acquisitions. Intra-cardiac flow was visualized using particle tracing and image quality based on the flow patterns of the particles was graded using a four-point scale.</p> <p>Results</p> <p>Good accuracy of SV quantification was found using 3 T 4D-SENSE (r<sup>2 </sup>= 0.86, -0.7 ± 7.6%) and although a larger bias was found on 1.5 T (r<sup>2 </sup>= 0.71, -3.6 ± 14.8%), the difference was not significant (p = 0.46). Accuracy of 4D k-t BLAST for SV was lower (p < 0.01) on 1.5 T (r<sup>2 </sup>= 0.65, -15.6 ± 13.7%) compared to 3 T (r<sup>2 </sup>= 0.64, -4.6 ± 10.0%). Peak flow was lower with 4D-SENSE at both 3 T and 1.5 T compared to 2D-flow (p < 0.01) and even lower with 4D k-t BLAST at both scanners (p < 0.01). Intracardiac flow visualization did not differ between 1.5 T and 3 T (p = 0.09) or between 4D-SENSE or 4D k-t BLAST (p = 0.85).</p> <p>Conclusions</p> <p>The present study showed that quantitative 4D flow accelerated with SENSE has good accuracy at 3 T and compares favourably to 1.5 T. 4D flow accelerated with k-t BLAST underestimate flow velocities and thereby yield too high bias for intra-cardiac quantitative in vivo use at the present time. For intra-cardiac 4D-flow visualization, however, 1.5 T and 3 T as well as SENSE or k-t BLAST can be used with similar quality.</p

    A data-driven synthesis of research evidence for domains of hearing loss, as reported by adults with hearing loss and their communication partners

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    A number of assessment tools exist to evaluate the impact of hearing loss, with little consensus among researchers as to either preference or psychometric adequacy. The item content of hearing loss assessment tools should seek to capture the impact of hearing loss on everyday life, but to date no one has synthesized the range of hearing loss complaints from the perspectives of the person with hearing loss and their communication partner. The current review aims to synthesize the evidence on person with hearing loss- and communication partner-reported complaints of hearing loss. Searches were conducted in Cos Conference Papers Index, the Cumulative Index to Nursing and Allied Health Literature, Excerpta Medica Database, PubMed, Web of Science, and Google Scholar to identify publications from May 1982 to August 2015. A manual search of four relevant journals updated the search to May 2017. Of the 9,516 titles identified, 78 records (comprising 20,306 participants) met inclusion criteria and were taken through to data collection. Data were analyzed using meta-ethnography to form domains representing the person with hearing loss- and communication partner-reported complaints of hearing loss as reported in research. Domains and subdomains mutual to both perspectives are related to ‘‘Auditory’’ (listening, communicating, and speaking), ‘‘Social’’ (relationships, isolation, social life, occupational, and interventions), and ‘‘Self’’ (effort and fatigue, emotions, identity, and stigma). Our framework contributes fundamental new knowledge and a unique resource that enables researchers and clinicians to consider the broader impacts of hearing loss. Our findings can also be used to guide questions during diagnostic assessment and to evaluate existing measures of hearing loss

    Heart valve disease: investigation by cardiovascular magnetic resonance

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    Cardiovascular magnetic resonance (CMR) has become a valuable investigative tool in many areas of cardiac medicine. Its value in heart valve disease is less well appreciated however, particularly as echocardiography is a powerful and widely available technique in valve disease. This review highlights the added value that CMR can bring in valve disease, complementing echocardiography in many areas, but it has also become the first-line investigation in some, such as pulmonary valve disease and assessing the right ventricle. CMR has many advantages, including the ability to image in any plane, which allows full visualisation of valves and their inflow/outflow tracts, direct measurement of valve area (particularly for stenotic valves), and characterisation of the associated great vessel anatomy (e.g. the aortic root and arch in aortic valve disease). A particular strength is the ability to quantify flow, which allows accurate measurement of regurgitation, cardiac shunt volumes/ratios and differential flow volumes (e.g. left and right pulmonary arteries). Quantification of ventricular volumes and mass is vital for determining the impact of valve disease on the heart, and CMR is the 'Gold standard' for this. Limitations of the technique include partial volume effects due to image slice thickness, and a low ability to identify small, highly mobile objects (such as vegetations) due to the need to acquire images over several cardiac cycles. The review examines the advantages and disadvantages of each imaging aspect in detail, and considers how CMR can be used optimally for each valve lesion
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