238 research outputs found

    Insight into hypertrophied hearts: a cardiovascular magnetic resonance study of papillary muscle mass and T1 mapping

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    AIMS: Left ventricular papillary muscles (LVPM) can appear disproportionately hypertrophied, particularly in Fabry disease (FD) where storage appears detectable by cardiovascular magnetic resonance (CMR) T1 mapping. The aim of the study was to measure LVPM mass in heart diseases with left ventricular hypertrophy (LVH) and to gain insight into the mechanisms of LVPM hypertrophy in FD. METHODS AND RESULTS: Four hundred and seventy-eight cases were retrospectively recruited: 125 FD, 85 hypertrophic cardiomyopathy (HCM), 67 amyloid, 82 aortic stenosis (AS), 40 hypertension, 79 controls. LVPM contribution to LVM was manually contoured on CMR short axis cines. T1 values (septal, LVPM) were measured using ShMOLLI sequences in FD and controls. LVPM contribution to LVM was highest in LVH+ve FD and significantly increased compared to all other LVH+ve groups (FD 13 ± 3%, HCM 10 ± 3%, amyloid 8 ± 2%, AS 7 ± 3%, hypertension 7 ± 2%, controls 7 ± 1%; P < 0.001). LVH+ve HCM also had significantly increased LVPM. In LVH−ve cohorts, only FD had significantly increased LVPM (11 ± 3%; P < 0.001). In FD there was concordant septal and LVPM T1. LVH+ve FD: when septal T1 was low, LVPM T1 was low in 90%. LVH−ve FD: when septal T1 was normal, LVPM T1 was normal in 70% (indicating no detectable storage); when septal T1 was low, 75% had low LVPM T1 (indicating storage). LVPM hypertrophy was similar between the low and normal septal T1 groups (11 ± 3% vs. 10 ± 3%, P = 0.08). CONCLUSION: Disproportionate hypertrophy of LVPMs in LVH+ve hearts occurred in FD and HCM. This phenomenon also occurred in LVH−ve FD. Low T1 was not always present in FD LVPM hypertrophy, implying additional mechanisms activating hypertrophy signalling pathways

    The time course of subsequent hospitalizations and associated costs in survivors of an ischemic stroke in Canada

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    BACKGROUND: Documentation of the hospitalizations rates following a stroke provides the inputs required for planning health services and to evaluate the economic efficiency of any new therapies. METHODS: Hospitalization rates by cause were examined using administrative data on 18,695 patients diagnosed with ischemic stroke (first or subsequent, excluding transient ischemic attack) in Saskatchewan, Canada between 1990 and 1995. Medical history was available retrospectively to January 1980 and follow-up was complete to March 2000. Analyses evaluated the rate and timing of all-cause and cardiovascular hospitalizations within discrete periods in the five years following the index stroke. Cardiovascular hospitalizations included patients with a primary diagnosis of ischemic stroke, transient ischemic attack, myocardial infarction, stable or unstable angina, heart failure or peripheral arterial disease. RESULTS: One-third (36%) of patients were identified by a hospitalized stroke. Mean age was 70.5 years, 48.0% were male, half had a history of stroke or a transient ischemic attack at the time of their index stroke. Three-quarters of the patients (72.7%) were hospitalized at least once during a mean follow-up of 4.6 years, accruing CAD $24 million in the first year alone. Of all hospitalizations, 20.4% were related to cardiovascular disease and 1.6% to bleeds. In the month following index stroke, 12.5% were admitted, an average of 1.04 times per patient hospitalized. Strokes accounted for 33% of all hospitalizations in the first month. The rate diminished steadily throughout the year and stabilized in the second year when approximately one-third of patients required hospitalization, at a rate of about one hospitalization for every two patient-years. Mean lengths of stay ranged from nine days to nearly 40 days. Close-fitting Weibull functions allow highly specific probability estimates. Other cardiovascular risk factors significantly increased hospitalization rates. CONCLUSION: After stroke, there are frequent hospitalizations accounting for substantial additional costs. Though these rates drop after one year, they remain high over time. The number of other cardiovascular causes of hospitalization confirms that stroke is a manifestation of disseminated atherothrombotic disease

    The use of herbal medicines by people with cancer: a cross-sectional survey

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    BACKGROUND: A large proportion of cancer patients are estimated to use herbal medicines, but data to substantiate this are lacking. This study aimed to investigate the prevalence of herbal medicine use among cancer patients in the West Midlands, and determine the characteristics predicting herbal medicine use. METHODS: A cross-sectional survey of oncology patients (n=1498) being followed up at a hospital in Coventry was undertaken. Recipients were asked about herbal medicine use since their cancer diagnosis, and the association between sociodemographic and cancer-related characteristics and herbal medicine use was evaluated. RESULTS: A total of 1134 responses were received (75.7%). The prevalence of herbal medicine use was 19.7% (95% CI: 17.4-22.1; n=223). Users were more likely to be affluent, female, and aged under 50 years. Usage increased with time since cancer diagnosis (X(2) for trend=4.63; P=0.031). A validation data set, derived from a survey of oncology patients in Birmingham (n=541) with differing socioeconomic characteristics showed no significant difference in estimated prevalence (16.6%; 95% CI: 11.9-22.2). CONCLUSION: A substantial number of people with cancer are likely to be taking herbal medicines. Understanding the self-medication behaviours of these individuals is essential if health-care professionals are to support treatment adherence and avoid unwanted pharmacological interactions

    Association between intra-radicular posts and periapical lesions in endodontically treated teeth

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    Introduction: A significant number of endodontically treated teeth restored with posts have associated periapical lesions, and several authors have discussed the probable causes of the development of these. Attention has been focused on restorative procedures performed after endodontic treatment and their association with the prognosis of endodontic therapy because a number of root-filled teeth will require post- and core-retained restorations. Purpose: The purpose of this study was to evaluate, by examination of periapical radiographs, whether the placement of intra-radicular posts in endodontically treated teeth may act as a risk factor for development of periapical lesions. Material and Methods: This case-control study analyzed periapical radiographs of 72 endodontically treated teeth with coronal restorations. All radiographs were obtained from a single private practice. Specimens were assigned to 2 groups: Group 1 (control) was composed of teeth without periapical lesions and Group 2 (case) was composed of teeth with periapical lesions. The number of teeth with and without posts in each group was recorded. Three calibrated examiners analyzed the radiographs visually under X4 magnification. Results: In Group 1, 28 (65.1%) out of 43 teeth were restored with posts. In Group 2, 24 (82.8%) out of 29 teeth had intra-radicular posts. The interpretation of chi-square test showed that these percentages were not significantly different (x²=2.687; p=0.101). Odds ratio was 2.571 (0.815-8.118), which indicates that there was no statistically significant association between periapical lesions and posts. Conclusion: Intra-radicular posts placed in endodontically treated teeth were not a significant risk factor for development of periapical lesions in the practice where the cohort of patients was treated

    Process skill rather than motor skill seems to be a predictor of costs for rehabilitation after a stroke in working age; a longitudinal study with a 1 year follow up post discharge

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    <p>Abstract</p> <p>Background</p> <p>In recent years a number of costs of stroke studies have been conducted based on incidence or prevalence and estimating costs at a given time. As there still is a need for a deeper understanding of factors influencing these costs the aim of this study was to calculate the direct and indirect costs in a younger (<65) sample of stroke patients and to explore factors affecting the costs.</p> <p>Methods</p> <p>Fifty-eight patients included in a study of home rehabilitation and followed for 1 year after discharge from the rehabilitation unit, were interviewed about their use of health care services, assistance, medications and assistive devices. Costs (defined as the cost for society) were calculated. A linear regression of cost and variables of functioning, ability, community integration and health-related quality of life was done.</p> <p>Results</p> <p>Inpatient care contributed substantially to the direct cost with a mean length of stay of 92 days. Rehabilitation during the first year constituted of an average of 28 days in day clinics, 38 physiotherapy sessions and 20 occupational therapy sessions. The total direct mean cost was 80 020 € and the indirect cost 35 129 €. The direct costs were influenced by the process skill (the ability to plan and perform a given task and to adapt when needed) and presence of aphasia. Indirect costs for informal care giving increased for patients with a lower health-related quality of life as well as a low score on home integration.</p> <p>Conclusion</p> <p>Costs are high in this group of young (< 65 years) stroke patients compared to other studies, partly due to the length of the stay and partly to loss of productivity.</p

    Sensitivity Analysis for Not-at-Random Missing Data in Trial-Based Cost-Effectiveness Analysis : A Tutorial

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    Cost-effectiveness analyses (CEA) of randomised controlled trials are a key source of information for health care decision makers. Missing data are, however, a common issue that can seriously undermine their validity. A major concern is that the chance of data being missing may be directly linked to the unobserved value itself [missing not at random (MNAR)]. For example, patients with poorer health may be less likely to complete quality-of-life questionnaires. However, the extent to which this occurs cannot be ascertained from the data at hand. Guidelines recommend conducting sensitivity analyses to assess the robustness of conclusions to plausible MNAR assumptions, but this is rarely done in practice, possibly because of a lack of practical guidance. This tutorial aims to address this by presenting an accessible framework and practical guidance for conducting sensitivity analysis for MNAR data in trial-based CEA. We review some of the methods for conducting sensitivity analysis, but focus on one particularly accessible approach, where the data are multiply-imputed and then modified to reflect plausible MNAR scenarios. We illustrate the implementation of this approach on a weight-loss trial, providing the software code. We then explore further issues around its use in practice

    When What's Left Is Right: Visuomotor Transformations in an Aged Population

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    Background: There has been little consensus as to whether age-related visuomotor adaptation effects are readily observable. Some studies have found slower adaptation, and/or reduced overall levels. In contrast, other methodologically similar studies have found no such evidence of aging effects on visuomotor adaptation. A crucial early step in successful adaptation is the ability to perform the necessary transformation to complete the task at hand. The present study describes the use of a viewing window paradigm to examine the effects of aging in a visuomotor transformation task. Methods: Two groups of participants, a young adult control group (age range 18–33 years old, mean age = 22) and an older adult group (age range 62–74, mean age = 68) completed a viewing window task that was controlled by the user via a computer touchscreen. Four visuomotor ‘‘flip’ ’ conditions were created by varying the relationship between the participant’s movement, and the resultant on-screen movement of the viewing window: 1) No flip 2) X-Axis and Y-axis body movements resulted in the opposite direction of movement of the viewing window. In each of the 3) Flip-X and 4) Flip-Y conditions, the solitary X- or Y-axes were reversed. Response times and movement of the window were recorded. Conclusions: Older participants demonstrated impairments in performing a required visuomotor transformation, as evidenced by more complex scanning patterns and longer scanning times when compared to younger control participants. These results provide additional evidence that the mechanisms involved in visuomotor transformation are negatively affected by age

    Shocked monazite chronometry: integrating microstructural and in situ isotopic age data for determining precise impact ages

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    Monazite is a robust geochronometer and occurs in a wide range of rock types. Monazite also records shock deformation from meteorite impact but the effects of impact-related microstructures on the U–Th–Pb systematics remain poorly constrained. We have, therefore, analyzed shock-deformed monazite grains from the central uplift of the Vredefort impact structure, South Africa, and impact melt from the Araguainha impact structure, Brazil, using electron backscatter diffraction, electron microprobe elemental mapping, and secondary ion mass spectrometry (SIMS). Crystallographic orientation mapping of monazite grains from both impact structures reveals a similar combination of crystal-plastic deformation features, including shock twins, planar deformation bands and neoblasts. Shock twins were documented in up to four different orientations within individual monazite grains, occurring as compound and/or type one twins in (001), (100), (10 1 ¯) , {110}, { 212 } , and type two (irrational) twin planes with rational shear directions in [ 0 1 ¯ 1 ¯ ] and [ 1 ¯ 1 ¯ 0 ]. SIMS U–Th–Pb analyses of the plastically deformed parent domains reveal discordant age arrays, where discordance scales with increasing plastic strain. The correlation between discordance and strain is likely a result of the formation of fast diffusion pathways during the shock event. Neoblasts in granular monazite domains are strain-free, having grown during the impact events via consumption of strained parent grains. Neoblastic monazite from the Inlandsee leucogranofels at Vredefort records a 207Pb/206Pb age of 2010 ± 15 Ma (2σ, n = 9), consistent with previous impact age estimates of 2020 Ma. Neoblastic monazite from Araguainha impact melt yield a Concordia age of 259 ± 5 Ma (2σ, n = 7), which is consistent with previous impact age estimates of 255 ± 3 Ma. Our results demonstrate that targeting discrete microstructural domains in shocked monazite, as identified through orientation mapping, for in situ U–Th–Pb analysis can date impact-related deformation. Monazite is, therefore, one of the few high-temperature geochronometers that can be used for accurate and precise dating of meteorite impacts
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