390 research outputs found
Teaching Evidence-Based Complementary and Alternative Medicine (EBCAM); Changing behaviours in the face of reticence: A cross-over trial
BACKGROUND: The effectiveness of teaching critical appraisal to students of Complementary and Alternative Medicine (CAM) has not been studied. In this study we attempt to determine if a workshop for final year students at a naturopathic college improved their ability to utilize critical appraisal concepts. METHODS: We assigned 83 Naturopathic Interns to two groups: Group A (n = 47) or Group B (n = 36). We conducted a baseline assessment of all subjects' critical appraisal skills. Group A was assigned to receive a 3 ½ hour workshop on Evidence Based Medicine (EBM) and Group B received a workshop on bioethics (control intervention). The groups critical appraisal skills were re-evaluated at this time. We then crossed over the intervention so that Group B received the EBM workshop while Group A received the bioethics workshop. Assessment of critical appraisal skills of the two groups was again performed. RESULTS: The students mean scores were similar in Group A (14.8) and Group B (15.0) after Group A had received the intervention and Group B had received the control (p = 0.75). Group scores were not significantly improved at the end of the trial compared to at the beginning of the study (Group A: 15.1 to 16.1) (Group B 15.6 to 15.9). Student's confidence in reading research papers also did not improve throughout the course of the study. CONCLUSION: The final year is a difficult but important time to teach critical appraisal and evidence skills. Single, short intervention programs will likely yield negligible results. A multi-factorial approach may be better suited to implementing EBCAM than single short interventions
Medical decision making for patients with Parkinson disease under Average Cost Criterion
Parkinson's disease (PD) is one of the most common disabling neurological disorders and results in substantial burden for patients, their families and the as a whole society in terms of increased health resource use and poor quality of life. For all stages of PD, medication therapy is the preferred medical treatment. The failure of medical regimes to prevent disease progression and to prevent long-term side effects has led to a resurgence of interest in surgical procedures. Partially observable Markov decision models (POMDPs) are a powerful and appropriate technique for decision making. In this paper we applied the model of POMDP's as a supportive tool to clinical decisions for the treatment of patients with Parkinson's disease. The aim of the model was to determine the critical threshold level to perform the surgery in order to minimize the total lifetime costs over a patient's lifetime (where the costs incorporate duration of life, quality of life, and monetary units). Under some reasonable conditions reflecting the practical meaning of the deterioration and based on the various diagnostic observations we find an optimal average cost policy for patients with PD with three deterioration levels
Crucial Role of the CB3-Region of Collagen IV in PARF-Induced Acute Rheumatic Fever
Acute rheumatic fever (ARF) and rheumatic heart disease are serious autoimmune sequelae to infections with Streptococcus pyogenes. Streptococcal M-proteins have been implicated in ARF pathogenesis. Their interaction with collagen type IV (CIV) is a triggering step that induces generation of collagen-specific auto-antibodies. Electron microscopy of the protein complex between M-protein type 3 (M3-protein) and CIV identified two prominent binding sites of which one is situated in the CB3-region of CIV. In a radioactive binding assay, M3-protein expressing S. pyogenes and S. gordonii bound the CB3-fragment. Detailed analysis of the interactions by surface plasmon resonance measurements and site directed mutagenesis revealed high affinity interactions with dissociation constants in the nanomolar range that depend on the recently described collagen binding motif of streptococcal M-proteins. Because of its role in the induction of disease-related collagen autoimmunity the motif is referred to as “peptide associated with rheumatic fever” (PARF). Both, sera of mice immunized with M3-protein as well as sera from patients with ARF contained anti-CB3 auto-antibodies, indicating their contribution to ARF pathogenesis. The identification of the CB3-region as a binding partner for PARF directs the further approaches to understand the unusual autoimmune pathogenesis of PARF-dependent ARF and forms a molecular basis for a diagnostic test that detects rheumatogenic streptococci
Density of Healthcare Providers and Patient Outcomes: Evidence from a Nationally Representative Multi-Site HIV Treatment Program in Uganda
This study examined the association between density of healthcare providers and patient outcomes using a large nationally representative cohort of patients receiving combination antiretroviral therapy (cART) in Uganda.Objective: We examined the association between density of healthcare providers and patient outcomes using a large nationally representative cohort of patients receiving combination antiretroviral therapy (cART) in Uganda.
Design: We obtained data from The AIDS Support Organization (TASO) in Uganda. Patients 18 years of age and older who initiated cART at TASO between 2004 and 2008 contributed to this analysis. The number of healthcare providers per 100 patients, the number of patients lost to follow-up per 100 person years and number of deaths per 100 person years were calculated. Spearman correlation was used to identify associations between patient loss to follow-up and mortality with the healthcare provider-patient ratios.
Results: We found no significant associations between the number of patients lost to follow-up and physicians (p = 0.45), nurses (p = 0.93), clinical officers (p = 0.80), field officers (p = 0.56), and healthcare providers overall (p = 0.83). Similarly, no significant associations were observed between mortality and physicians (p = 0.65), nurses (p = 0.49), clinical officers
(p = 0.73), field officers (p = 0.78), and healthcare providers overall (p = 0.73).
Conclusions: Patient outcomes, as measured by loss to follow-up and mortality, were not significantly associated with the number of doctors, nurses, clinical officers, field officers, or healthcare providers overall. This may suggest that that other factors, such as the presence of volunteer patient supporters or broader political or socioeconomic influences, may be more closely associated with outcomes of care among patients on cART in Uganda
Adherence to 24-Hour Movement Guidelines for the Early Years and associations with social-cognitive development among Australian preschool children
Background: The new Australian 24-Hour Movement Guidelines for the Early Years recommend that, for preschoolers, a healthy 24-h includes: i) ≥180 min of physical activity, including ≥60 min of energetic play, ii) ≤1 h of sedentary screen time, and iii) 10–13 h of good quality sleep. Using an Australian sample, this study reports the proportion of preschool children meeting these guidelines and investigates associations with social-cognitive development.
Methods: Data from 248 preschool children (mean age = 4.2 ± 0.6 years, 57% boys) participating in the PATH-ABC study were analyzed. Children completed direct assessments of physical activity (accelerometry) and social cognition (the Test of Emotional Comprehension (TEC) and Theory of Mind (ToM)). Parents reported on children’s screen time and sleep. Children were categorised as meeting/not meeting: i) individual guidelines, ii) combinations of two guidelines, or iii) all three guidelines. Associations were examined using linear regression adjusting for child age, sex, vocabulary, area level socio-economic status and childcare level clustering.
Results: High proportions of children met the physical activity (93.1%) and sleep (88.7%) guidelines, whereas fewer met the screen time guideline (17.3%). Overall, 14.9% of children met all three guidelines. Children meeting the sleep guideline performed better on TEC than those who did not (mean difference [MD] = 1.41; 95% confidence interval (CI) = 0.36, 2.47). Children meeting the sleep and physical activity or sleep and screen time guidelines also performed better on TEC (MD = 1.36; 95% CI = 0.31, 2.41) and ToM (MD = 0.25; 95% CI = −0.002, 0.50; p = 0.05), respectively, than those who did not. Meeting all three guidelines was associated with better ToM performance (MD = 0.28; 95% CI = −0.002, 0.48, p = 0.05), while meeting a larger number of guidelines was associated with better TEC (3 or 2 vs. 1/none, p < 0.02) and ToM performance (3 vs. 2, p = 0.03).
Conclusions: Strategies to promote adherence to the 24-Hour Movement Behaviour Guidelines for the Early Years among preschool children are warranted. Supporting preschool children to meet all guidelines or more guidelines, particularly the sleep and screen time guidelines, may be beneficial for their social-cognitive development
Bearings in Hip Arthroplasty:Joint Registries vs Precision Medicine: Review Article
Background: Precision medicine has been adopted in a range of clinical settings where omics data have led to greater characterisation of disease and stratification of patients into subcategories of phenotypes and pathologies. However, in orthopaedics, precision medicine lags behind other disciplines such as cancer. Joint registries have now amassed a huge body of data pertaining to implant performance which can be broken down into performance statistics for different material types in different cohorts of patients. The National Joint Registry of England, Wales and Northern Ireland (NJR) is now one of the largest datasets available. Other registries such as those from Sweden and Australia however contain longer follow-up. Together, these registries can provide a wealth of informative for the orthopaedics community when considering which implant to give to any particular patient. Questions/Purposes: We aim to explore the benefits of combining multiple large data streams including joint registries, published data on osteoarthritis (OA) pathogenesis and pathology and data concerning performance of each implant material combination in terms of biocompatibility. We believe that this analysis will provide a comprehensive overview of implant performance hopefully aiding surgeons in making more informed choices about which implant should be used in which patient. Methods: Data from three joint registries were combined with established literature to highlight the heterogeneity of OA disease and the different clinical outcomes following arthroplasty with a range of material types. Results: This review confirms that joint registries are unable to consider differences in arthritis presentation or underlying drivers of pathology. OA is now recognised to present with varying pathology with differing morbidity in different patient populations. Equally, just as OA is a heterogeneous disease, there are disparate responses to wear debris from different material combinations used in joint replacement surgery. This has been highlighted by recent high-profile scrutiny of early failure of metal-on-metal total hip replacement (THR) implants. Conclusions: Bringing together data from joint registries, biomarker analysis, phenotyping of OA patients and knowledge of how different patients respond to implant debris will lead to a truly personalised approach to treating OA patients, ensuring that the correct implant is given to the correct patient at the correct time
A Functional Variant in MicroRNA-146a Promoter Modulates Its Expression and Confers Disease Risk for Systemic Lupus Erythematosus
Systemic lupus erythematosus (SLE) is a complex autoimmune disease with a strong genetic predisposition, characterized by an upregulated type I interferon pathway. MicroRNAs are important regulators of immune homeostasis, and aberrant microRNA expression has been demonstrated in patients with autoimmune diseases. We recently identified miR-146a as a negative regulator of the interferon pathway and linked the abnormal activation of this pathway to the underexpression of miR-146a in SLE patients. To explore why the expression of miR-146a is reduced in SLE patients, we conducted short parallel sequencing of potentially regulatory regions of miR-146a and identified a novel genetic variant (rs57095329) in the promoter region exhibiting evidence for association with SLE that was replicated independently in 7,182 Asians (Pmeta = 2.74×10−8, odds ratio = 1.29 [1.18–1.40]). The risk-associated G allele was linked to reduced expression of miR-146a in the peripheral blood leukocytes of the controls. Combined functional assays showed that the risk-associated G allele reduced the protein-binding affinity and activity of the promoter compared with those of the promoter containing the protective A allele. Transcription factor Ets-1, encoded by the lupus-susceptibility gene ETS1, identified in recent genome-wide association studies, binds near this variant. The manipulation of Ets-1 levels strongly affected miR-146a promoter activity in vitro; and the knockdown of Ets-1, mimicking its reduced expression in SLE, directly impaired the induction of miR-146a. We also observed additive effects of the risk alleles of miR-146a and ETS1. Our data identified and confirmed an association between a functional promoter variant of miR-146a and SLE. This risk allele had decreased binding to transcription factor Ets-1, contributing to reduced levels of miR-146a in SLE patients
Intervention in gene regulatory networks via greedy control policies based on long-run behavior
<p>Abstract</p> <p>Background</p> <p>A salient purpose for studying gene regulatory networks is to derive intervention strategies, the goals being to identify potential drug targets and design gene-based therapeutic intervention. Optimal stochastic control based on the transition probability matrix of the underlying Markov chain has been studied extensively for probabilistic Boolean networks. Optimization is based on minimization of a cost function and a key goal of control is to reduce the steady-state probability mass of undesirable network states. Owing to computational complexity, it is difficult to apply optimal control for large networks.</p> <p>Results</p> <p>In this paper, we propose three new greedy stationary control policies by directly investigating the effects on the network long-run behavior. Similar to the recently proposed mean-first-passage-time (MFPT) control policy, these policies do not depend on minimization of a cost function and avoid the computational burden of dynamic programming. They can be used to design stationary control policies that avoid the need for a user-defined cost function because they are based directly on long-run network behavior; they can be used as an alternative to dynamic programming algorithms when the latter are computationally prohibitive; and they can be used to predict the best control gene with reduced computational complexity, even when one is employing dynamic programming to derive the final control policy. We compare the performance of these three greedy control policies and the MFPT policy using randomly generated probabilistic Boolean networks and give a preliminary example for intervening in a mammalian cell cycle network.</p> <p>Conclusion</p> <p>The newly proposed control policies have better performance in general than the MFPT policy and, as indicated by the results on the mammalian cell cycle network, they can potentially serve as future gene therapeutic intervention strategies.</p
A propofol binding site on mammalian GABAA receptors identified by photolabeling
Propofol is the most important intravenous general anesthetic in current clinical use. It acts by potentiating GABA(A) receptors, but where it binds to this receptor is not known and has been a matter of some controversy. We have synthesized a novel propofol analogue photolabeling reagent that has a biological activity very similar to that of propofol. We confirmed that this reagent labeled known propofol binding sites in human serum albumin which have been identified using X-ray crystallography. Using a combination of the protiated label and a deuterated version, and mammalian receptors labeled in intact membranes, we have identified a novel binding site for propofol in GABA(A) receptors consisting of both β(3) homopentamers and α(1)β(3) heteropentamers. The binding site is located within the β subunit, at the interface between the transmembrane domains and the extracellular domain, and lies close to known determinants of anesthetic sensitivity in transmembrane segments TM1 and TM2
Orbitally forced ice sheet fluctuations during the Marinoan Snowball Earth glaciation
Two global glaciations occurred during the Neoproterozoic. Snowball Earth theory posits that these were terminated after millions of years of frigidity when initial warming from rising atmospheric CO2 concentrations was amplified by the reduction of ice cover and hence a reduction in planetary albedo. This scenario implies that most of the geological record of ice cover was deposited in a brief period of melt-back. However, deposits in low palaeo-latitudes show evidence of glacial–interglacial cycles. Here we analyse the sedimentology and oxygen and sulphur isotopic signatures of Marinoan Snowball glaciation deposits from Svalbard, in the Norwegian High Arctic. The deposits preserve a record of oscillations in glacier extent and hydrologic conditions under uniformly high atmospheric CO2 concentrations. We use simulations from a coupled three-dimensional ice sheet and atmospheric general circulation model to show that such oscillations can be explained by orbital forcing in the late stages of a Snowball glaciation. The simulations suggest that while atmospheric CO2 concentrations were rising, but not yet at the threshold required for complete melt-back, the ice sheets would have been sensitive to orbital forcing. We conclude that a similar dynamic can potentially explain the complex successions observed at other localities
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