767 research outputs found
The effects of melatonin versus placebo on delirium in hip fracture patients: study protocol of a randomised, placebo-controlled, double blind trial
<p>Abstract</p> <p>Background</p> <p>With an ageing population, older persons become a larger part of the hospital population. The incidence of delirium is high in this group, and experiencing delirium has major short- and long-term sequelae, which makes prevention crucial. During delirium, a disruption of the sleep-wake cycle is frequently observed. Melatonin plays an important role in the regulation of the sleep-wake cycle, so this raised the hypothesis that alterations in the metabolism of melatonin might play an important role in the development of delirium. The aim of this article is to describe the design of a randomised, placebo controlled double-blind trial that is currently in progress and that investigates the effects of melatonin versus placebo on delirium in older, postoperative hip fracture patients.</p> <p>Methods/Design</p> <p>Acutely hospitalised patients aged 65 years or older admitted for surgical repair of hip fracture are randomised (n = 452) into a treatment or placebo group. Prophylactic treatment consists of orally administered melatonin (3 mg) at 21:00 h on five consecutive days. The primary outcome is the occurrence of delirium, to be diagnosed according to the Confusion Assessment Method, within eight days after start of the study medication. Secondary outcomes are delirium severity, measured by the Delirium Rating Scale; duration of delirium; differences in subtypes of delirium; differences in total length of hospital stay; total dose of antipsychotics and/or benzodiazepine use during delirium; and in-hospital complications. In the twelve-month follow up visit, cognitive function is measured by a Mini-Mental state examination and the Informant Questionnaire on Cognitive Decline in the Elderly. Functional status is assessed with the Katz ADL index score (patient and family version) and grip strength measurement. The outcomes of these assessments are compared to the outcomes that were obtained during admission.</p> <p>Discussion</p> <p>The proposed study will contribute to our knowledge because studies on the prophylactic treatment of delirium with long term follow up remain scarce. The results may lead to a prophylactic treatment for frail older persons at high risk for delirium that is safe, effective, and easily implementable in daily practice.</p> <p>Trial registration</p> <p>Dutch Clinical Trial Registry: <a href="http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=1576">NTR1576</a></p
Determining utility values in patients with anterior cruciate ligament tears using clinical scoring systems
BACKGROUND: Several instruments and clinical scoring systems have been established to evaluate patients with ligamentous knee injuries. A comparison of individual articles in the literature is challenging, not only because of heterogeneity in methodology, but also due to the variety of the scoring systems used to document clinical outcomes. There is limited information about the correlation between used scores and quality of life with no information being available on the impact of each score on the utility values. The aim of this study was to compare the most commonly used scores for evaluating patients with anterior cruciate ligament (ACL) injuries, and to establish corresponding utility values. These values will be used for the interpretation and comparison of outcome results in the currently available literature for different treatment options. METHODS: Four hypothetical vignettes were defined, based on different levels of activities after rupture of the ACL to simulate typical situations seen in daily practice. A questionnaire, including the Health Utility Index (HUI) for utility values, the IKDC subjective score, the Lysholm and the Tegner score, was created and 25 orthopedic surgeons were asked to fill the questionnaire for each hypothetical patient as proxies for all patients they had treated and who would fit in that hypothetical vignette. RESULTS: The utility value as an indicator for quality of life increased with the level of activity. Having discomforts already during normal activities of daily living was rated with a mean utility value of 0.37 ± 0.19, half of that of a situation where mild sport activity was possible without discomfort (0.78 ± 0.11). All investigated scores were able to distinguish clearly (p < 0.05) between the hypothetical vignettes. However, the utility values correlated best with the IKDC subjective score (r = 0.86, p < 0.001) followed by the Lysholm score (r = 0.77, p < 0.001) and the Tegner score (r = 0.77, p < 0.001). CONCLUSIONS: Here we report the correlation between the most commonly used scores for the assessment of patients with a ruptured ACL and utility values as an indicator of quality of life. Assumptions were based on expert opinions to provide a possible transformation algorithm. The IKDC subjective knee score showed the highest correlation to the quality of life (i.e. HUI) in patients with a ruptured ACL. Confirmation of our results is needed by systematic inclusion of a measurement instrument for utility values in future clinical studies beside the already used clinical knee scoring systems
Dopaminergic Activation of Estrogen Receptors Induces Fos Expression within Restricted Regions of the Neonatal Female Rat Brain
Steroid receptor activation in the developing brain influences a variety of cellular processes that endure into adulthood, altering both behavior and physiology. Recent data suggests that dopamine can regulate expression of progestin receptors within restricted regions of the developing rat brain by activating estrogen receptors in a ligand-independent manner. It is unclear whether changes in neuronal activity induced by dopaminergic activation of estrogen receptors are also region specific. To investigate this question, we examined where the dopamine D1-like receptor agonist, SKF 38393, altered Fos expression via estrogen receptor activation. We report that dopamine D1-like receptor agonist treatment increased Fos protein expression within many regions of the developing female rat brain. More importantly, prior treatment with an estrogen receptor antagonist partially reduced D1-like receptor agonist-induced Fos expression only within the bed nucleus of the stria terminalis and the central amygdala. These data suggest that dopaminergic activation of estrogen receptors alters neuronal activity within restricted regions of the developing rat brain. This implies that ligand-independent activation of estrogen receptors by dopamine might organize a unique set of behaviors during brain development in contrast to the more wide spread ligand activation of estrogen receptors by estrogen
Early Palaeozoic ocean anoxia and global warming driven by the evolution of shallow burrowing
The evolution of burrowing animals forms a defining event in the history of the Earth. It has been hypothesised that the expansion of seafloor burrowing during the Palaeozoic altered the biogeochemistry of the oceans and atmosphere. However, whilst potential impacts of bioturbation on the individual phosphorus, oxygen and sulphur cycles have been considered, combined effects have not been investigated, leading to major uncertainty over the timing and magnitude of the Earth system response to the evolution of bioturbation. Here we integrate the evolution of bioturbation into the COPSE model of global biogeochemical cycling, and compare quantitative model predictions to multiple geochemical proxies. Our results suggest that the advent of shallow burrowing in the early Cambrian contributed to a global low-oxygen state, which prevailed for ~100 million years. This impact of bioturbation on global biogeochemistry likely affected animal evolution through expanded ocean anoxia, high atmospheric CO2 levels and global warming
Effects and feasibility of a standardised orientation and mobility training in using an identification cane for older adults with low vision: design of a randomised controlled trial
<p>Abstract</p> <p>Background</p> <p>Orientation and mobility training (O&M-training) in using an identification cane, also called symbol cane, is provided to people with low vision to facilitate independent participation in the community. In The Netherlands this training is mainly practice-based because a standardised and validly evaluated O&M-training in using the identification cane is lacking. Recently a standardised O&M-training in using the identification cane was developed. This training consists of two face-to-face sessions and one telephone session during which, in addition to usual care, the client's needs regarding mobility are prioritised, and cognitive restructuring techniques, action planning and contracting are applied to facilitate the use of the cane. This paper presents the design of a randomised controlled trial aimed to evaluate this standardised O&M-training in using the identification cane in older adults with low vision.</p> <p>Methods/design</p> <p>A parallel group randomised controlled trial was designed to compare the standardised O&M-training with usual care, i.e. the O&M-training commonly provided by the mobility trainer. Community-dwelling older people who ask for support at a rehabilitation centre for people with visual impairment and who are likely to receive an O&M-training in using the identification cane are included in the trial (N = 190). The primary outcomes of the effect evaluation are ADL self care and visual functioning with respect to distance activities and mobility. Secondary outcomes include quality of life, feelings of anxiety, symptoms of depression, fear of falling, and falls history. Data for the effect evaluation are collected by means of telephone interviews at baseline, and at 5 and 17 weeks after the start of the O&M-training. In addition to an effect evaluation, a process evaluation to study the feasibility of the O&M-training is carried out.</p> <p>Discussion</p> <p>The screening procedure for eligible participants started in November 2007 and will continue until October 2009. Preliminary findings regarding the evaluation are expected in the course of 2010. If the standardised O&M-training is more effective than the current O&M-training or, in case of equal effectiveness, is considered more feasible, the training will be embedded in the Dutch national instruction for mobility trainers.</p> <p>Trial registration</p> <p>ClinicalTrials.gov NCT00946062</p
Compressed representation of a partially defined integer function over multiple arguments
In OLAP (OnLine Analitical Processing) data are analysed in an n-dimensional cube. The cube may be represented as a partially defined function over n arguments. Considering that often the function is not defined everywhere, we ask: is there a known way of representing the function or the points in which it is defined, in a more compact manner than the trivial one
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