9 resultados para Rigor
em BORIS: Bern Open Repository and Information System - Berna - Suiça
Resumo:
INTRODUCTION Post-mortem cardiac MR exams present with different contraction appearances of the left ventricle in cardiac short axis images. It was hypothesized that the grade of post-mortem contraction may be related to the post-mortem interval (PMI) or cause of death and a phenomenon caused by internal rigor mortis that may give further insights in the circumstances of death. METHOD AND MATERIALS The cardiac contraction grade was investigated in 71 post-mortem cardiac MR exams (mean age at death 52y, range 12-89y; 48 males, 23 females). In cardiac short axis images the left ventricular lumen volume as well as the left ventricular myocardial volume were assessed by manual segmentation. The quotient of both (LVQ) represents the grade of myocardial contraction. LVQ was correlated to the PMI, sex, age, cardiac weight, body mass and height, cause of death and pericardial tamponade when present. In cardiac causes of death a separate correlation was investigated for acute myocardial infarction cases and arrhythmic deaths. RESULTS LVQ values ranged from 1.99 (maximum dilatation) to 42.91 (maximum contraction) with a mean of 15.13. LVQ decreased slightly with increasing PMI, however without significant correlation. Pericardial tamponade positively correlated with higher LVQ values. Variables such as sex, age, body mass and height, cardiac weight and cause of death did not correlate with LVQ values. There was no difference in LVQ values for myocardial infarction without tamponade and arrhythmic deaths. CONCLUSION Based on the observation in our investigated cases, the phenomenon of post-mortem myocardial contraction cannot be explained by the influence of the investigated variables, except for pericardial tamponade cases. Further research addressing post-mortem myocardial contraction has to focus on other, less obvious factors, which may influence the early post-mortem phase too.
Resumo:
The release of phosphate (Pi) is an important element in actomyosin function and has been shown to be accelerated by the binding of myosin to actin. To provide information about the structural elements important for Pi release, possible escape pathways from various isolated myosin II structures have been determined by molecular dynamics simulations designed for studying such slow processes. The residues forming the pathways were identified and their role was evaluated by mutant simulations. Pi release is slow in the pre-powerstroke structure, an important element in preventing the powerstroke prior to actin binding, and is much more rapid for Pi modeled into the post-rigor and rigor-like structures. The previously proposed backdoor route is dominant in the pre-powerstroke and post-rigor states, whereas a different path is most important in the rigor-like state. This finding suggests a mechanism for the actin-activated acceleration of Pi release.
Resumo:
BACKGROUND CONTEXT: The Neck Disability Index frequently is used to measure outcomes of the neck. The statistical rigor of the Neck Disability Index has been assessed with conflicting outcomes. To date, Confirmatory Factor Analysis of the Neck Disability Index has not been reported for a suitably large population study. Because the Neck Disability Index is not a condition-specific measure of neck function, initial Confirmatory Factor Analysis should consider problematic neck patients as a homogenous group. PURPOSE: We sought to analyze the factor structure of the Neck Disability Index through Confirmatory Factor Analysis in a symptomatic, homogeneous, neck population, with respect to pooled populations and gender subgroups. STUDY DESIGN: This was a secondary analysis of pooled data. PATIENT SAMPLE: A total of 1,278 symptomatic neck patients (67.5% female, median age 41 years), 803 nonspecific and 475 with whiplash-associated disorder. OUTCOME MEASURES: The Neck Disability Index was used to measure outcomes. METHODS: We analyzed pooled baseline data from six independent studies of patients with neck problems who completed Neck Disability Index questionnaires at baseline. The Confirmatory Factor Analysis was considered in three scenarios: the full sample and separate sexes. Models were compared empirically for best fit. RESULTS: Two-factor models have good psychometric properties across both the pooled and sex subgroups. However, according to these analyses, the one-factor solution is preferable from both a statistical perspective and parsimony. The two-factor model was close to significant for the male subgroup (p<.07) where questions separated into constructs of mental function (pain, reading headaches and concentration) and physical function (personal care, lifting, work, driving, sleep, and recreation). CONCLUSIONS: The Neck Disability Index demonstrated a one-factor structure when analyzed by Confirmatory Factor Analysis in a pooled, homogenous sample of neck problem patients. However, a two-factor model did approach significance for male subjects where questions separated into constructs of mental and physical function. Further investigations in different conditions, subgroup and sex-specific populations are warranted.
Resumo:
Surgery for Parkinson's Disease (PD) is being increasingly used. The main reason for this renewal in surgical treatment for PD is the "deep brain stimulation" (DBS) that replaced the previously used stereotactic lesions in most centers. DBS allows a focal specific electrical stimulation of basal ganglia target instead of an irreversible lesion. Mainly bilateral DBS of the nucleus subthalamicus is now an established surgical treatment for PD. But DBS of the Globus pallidus internus and of the thalamus should still be considered in selected patients. DBS is an efficient treatment for motor complication of PD that can no longer be controlled by drug treatment. Dyskinesia, bradykinesia, tremor and rigor can be improved by DBS and the medication can be reduced. It is still unclear, however, how the improvement in motor symptoms affects quality of life in the long term. Furthermore, patients with severe cognitive and psychiatric symptoms as well as patients with severe axial symptoms should not be operated since these symptoms may worsen after surgery.
Resumo:
Pathologically elevated body core temperature, measured at the death scene, is an important finding in medico-legal investigation of violent deaths. An abnormally high rectal temperature at any death scene may point to an underlying pathology, the influence of certain drugs or a hidden cerebral traumatism, and death by suffocation which would remain undetected without further medico-legal investigations. Furthermore, hyperthermia and fever, if unrecognized, may result in an erroneous forensic estimation of time since death in the early postmortem period by the "Henssge method." By a retrospective study of 744 cases, the authors demonstrate that hyperthermia is a finding with an incidence of 10% of all cases of violent death. The main causes are: influence of drugs, malignant tumors, cerebral hypoxia as a result of suffocation, infections, and systemic inflammatory disorders. As a consequence it must be stated, that hyperthermia must be excluded in every medico-legal death scene investigation by a correct measurement of body core temperature and a comparison between the cooling rate of the body and the behavior of early postmortem changes, notably livor and rigor mortis.
Resumo:
Because of the unknown usage scenarios, designing the elementary services of a service-oriented architecture (SOA), which form the basis for later composition, is rather difficult. Various design guide lines have been proposed by academia, tool vendors and consulting companies, but they differ in the rigor of validation and are often biased toward some technology. For that reason a multiple-case study was conducted in five large organizations that successfully introduced SOA in their daily business. The observed approaches are contrasted with the findings from a literature review to derive some recommendations for SOA service design.
Resumo:
Background: The CAMbrella coordination action was funded within the Framework Programme 7. Its aim is to provide a research roadmap for clinical and epidemiological research for complementary and alternative medicine (CAM) that is appropriate for the health needs of European citizens and acceptable to their national research institutes and healthcare providers in both public and private sectors. One major issue in the European research agenda is the demographic change and its impact on health care. Our vision for 2020 is that there is an evidence base that enables European citizens to make informed decisions about CAM, both positive and negative. This roadmap proposes a strategic research agenda for the field of CAM designed to address future European health care challenges. This roadmap is based on the results of CAMbrella’s several work packages, literature reviews and expert discussions including a consensus meeting. Methods: We first conducted a systematic literature review on key issues in clinical and epidemiological research in CAM to identify the general concepts, methods and the strengths and weaknesses of current CAM research. These findings were discussed in a workshop (Castellaro, Italy, September 7–9th 2011) with international CAM experts and strategic and methodological recommendations were defined in order to improve the rigor and relevance of CAM research. These recommendations provide the basis for the research roadmap, which was subsequently discussed in a consensus conference (Järna, Sweden, May 9–11th 2012) with all CAMbrella members and the CAMbrella advisory board. The roadmap was revised after this discussion in CAMbrella Work Package (WP) 7 and finally approved by CAMbrella’s scientific steering committee on September 26th 2012. Results: Our main findings show that CAM is very heterogenous in terms of definitions and legal regulations between the European countries. In addition, citizens’ needs and attitudes towards CAM as well as the use and provision of CAM differ significantly between countries. In terms of research methodology, there was consensus that CAM researchers should make use of all the commonly accepted scientific research methods and employ those with utmost diligence combined in a mixed methods framework. Conclusions: We propose 6 core areas of research that should be investigated to achieve a robust knowledge base and to allow stakeholders to make informed decisions. These are: Research into the prevalence of CAM in Europe: Reviews show that we do not know enough about the circumstances in which CAM is used by Europeans. To enable a common European strategic approach, a clear picture of current use is of the utmost importance. Research into differences regarding citizens’ attitudes and needs towards CAM: Citizens are the driver for CAM utilization. Their needs and views on CAM are a key priority, and their interests must be investigated and addressed in future CAM research. Research into safety of CAM: Safety is a key issue for European citizens. CAM is considered safe, but reliable data is scarce although urgently needed in order to assess the risk and cost-benefit ratio of CAM. Research into the comparative effectiveness of CAM: Everybody needs to know in what situation CAM is a reasonable choice. Therefore, we recommend a clear emphasis on concurrent evaluation of the overall effectiveness of CAM as an additional or alternative treatment strategy in real-world settings. Research into effects of context and meaning: The impact of effects of context and meaning on the outcome of CAM treatments must be investigated; it is likely that they are significant. Research into different models of CAM health care integration: There are different models of CAM being integrated into conventional medicine throughout Europe, each with their respective strengths and limitations. These models should be described and concurrently evaluated; innovative models of CAM provision in health care systems should be one focus for CAM research. We also propose a methodological framework for CAM research. We consider that a framework of mixed methodological approaches is likely to yield the most useful information. In this model, all available research strategies including comparative effectiveness research utilising quantitative and qualitative methods should be considered to enable us to secure the greatest density of knowledge possible. Stakeholders, such as citizens, patients and providers, should be involved in every stage of developing the specific and relevant research questions, study design and the assurance of real-world relevance for the research. Furthermore, structural and sufficient financial support for research into CAM is needed to strengthen CAM research capacity if we wish to understand why it remains so popular within the EU. In order to consider employing CAM as part of the solution to the health care, health creation and self-care challenges we face by 2020, it is vital to obtain a robust picture of CAM use and reliable information about its cost, safety and effectiveness in real-world settings. We need to consider the availability, accessibility and affordability of CAM. We need to engage in research excellence and utilise comparative effectiveness approaches and mixed methods to obtain this data. Our recommendations are both strategic and methodological. They are presented for the consideration of researchers and funders while being designed to answer the important and implicit questions posed by EU citizens currently using CAM in apparently increasing numbers. We propose that the EU actively supports an EUwide strategic approach that facilitates the development of CAM research. This could be achieved in the first instance through funding a European CAM coordinating research office dedicated to foster systematic communication between EU governments, public, charitable and industry funders as well as researchers, citizens and other stakeholders. The aim of this office would be to coordinate research strategy developments and research funding opportunities, as well as to document and disseminate international research activities in this field. With the aim to develop sustainability as second step, a European Centre for CAM should be established that takes over the monitoring and further development of a coordinated research strategy for CAM, as well as it should have funds that can be awarded to foster high quality and robust independent research with a focus on citizens health needs and pan-European collaboration. We wish to establish a solid funding for CAM research to adequately inform health care and health creation decision-making throughout the EU. This centre would ensure that our vision of a common, strategic and scientifically rigorous approach to CAM research becomes our legacy and Europe’s reality. We are confident that our recommendations will serve these essential goals for EU citizens.
Resumo:
INTRODUCTION As the importance of systematic review (SR) conclusions relies upon the scientific rigor of methods and the currency of evidence, we aimed to investigate the currency of orthodontic SRs using as proxy the time from the initial search to publication. Additionally, SR information regarding reporting guidelines, registration, and literature searches were recorded when available. MATERIALS AND METHODS A systematic PubMed search was carried out using the Clinical Queries page to identify orthodontic SRs cited between 1 January 2008 and 7 November 2013. Data related to reporting guidelines, review registration, dates of review processing, literature search, and abstract reporting were retrieved and classified by journal type. Survival analysis was used to assess the time to reach predefined manuscript stages for orthodontic and non-orthodontic journals. RESULTS One hundred twenty seven of the originally identified 585 SRs were considered eligible. The median interval from search until publication was 13.2 months (interquartile range: IQR = 9.7 months) irrespective of the journal type. There was evidence (P = 0.05) that SRs published by non-orthodontic journals appeared in PubMed faster than in orthodontic journals (non-orthodontic: median = 6.5 months; IQR = 5.7 months; orthodontic: median = 10.2 months; IQR = 5.6 months) from submission to publication and from acceptance to publication (non-orthodontic: median = 1.5 months; IQR = 2.4 months; orthodontic: median = 6.0 months; IQR = 6.2 months; P < 0.001). More than half of these SRs did not cite adherence to any reporting guidelines, whereas all but five studies were not prospectively registered. Search of unpublished research was undertaken in approximately 21 per cent and 29 per cent of the SRs published in non-orthodontic and orthodontic periodicals, respectively. CONCLUSIONS This study indicates that SR users should be aware that median time for orthodontic SRs from search to publication is 13.2 months. SRs published in non-orthodontic journals are likely to be more current in terms of submission until time to publication and acceptance until time to publication compared with those published in orthodontic journals.
Resumo:
Systematic consideration of scientific support is a critical element in developing and, ultimately, using adverse outcome pathways (AOPs) for various regulatory applications. Though weight of evidence (WoE) analysis has been proposed as a basis for assessment of the maturity and level of confidence in an AOP, methodologies and tools are still being formalized. The Organization for Economic Co-operation and Development (OECD) Users' Handbook Supplement to the Guidance Document for Developing and Assessing AOPs (OECD 2014a; hereafter referred to as the OECD AOP Handbook) provides tailored Bradford-Hill (BH) considerations for systematic assessment of confidence in a given AOP. These considerations include (1) biological plausibility and (2) empirical support (dose-response, temporality, and incidence) for Key Event Relationships (KERs), and (3) essentiality of key events (KEs). Here, we test the application of these tailored BH considerations and the guidance outlined in the OECD AOP Handbook using a number of case examples to increase experience in more transparently documenting rationales for assigned levels of confidence to KEs and KERs, and to promote consistency in evaluation within and across AOPs. The major lessons learned from experience are documented, and taken together with the case examples, should contribute to better common understanding of the nature and form of documentation required to increase confidence in the application of AOPs for specific uses. Based on the tailored BH considerations and defining questions, a prototype quantitative model for assessing the WoE of an AOP using tools of multi-criteria decision analysis (MCDA) is described. The applicability of the approach is also demonstrated using the case example aromatase inhibition leading to reproductive dysfunction in fish. Following the acquisition of additional experience in the development and assessment of AOPs, further refinement of parameterization of the model through expert elicitation is recommended. Overall, the application of quantitative WoE approaches hold promise to enhance the rigor, transparency and reproducibility for AOP WoE determinations and may play an important role in delineating areas where research would have the greatest impact on improving the overall confidence in the AOP.