175 research outputs found
A parasite-derived 68-mer peptide ameliorates autoimmune disease in murine models of Type 1 diabetes and multiple sclerosis
© 2016 cThe Author(s). Helminth parasites secrete molecules that potently modulate the immune responses of their hosts and, therefore, have potential for the treatment of immune-mediated human diseases. FhHDM-1, a 68-mer peptide secreted by the helminth parasite Fasciola hepatica, ameliorated disease in two different murine models of autoimmunity, type 1 diabetes and relapsing-remitting immune-mediated demyelination. Unexpectedly, FhHDM-1 treatment did not affect the proliferation of auto-antigen specific T cells or their production of cytokines. However, in both conditions, the reduction in clinical symptoms was associated with the absence of immune cell infiltrates in the target organ (islets and the brain tissue). Furthermore, after parenteral administration, the FhHDM-1 peptide interacted with macrophages and reduced their capacity to secrete pro-inflammatory cytokines, such as TNF and IL-6. We propose this inhibition of innate pro-inflammatory immune responses, which are central to the initiation of autoimmunity in both diseases, prevented the trafficking of autoreactive lymphocytes from the periphery to the site of autoimmunity (as opposed to directly modulating their function per se), and thus prevented tissue destruction. The ability of FhHDM-1 to modulate macrophage function, combined with its efficacy in disease prevention in multiple models, suggests that FhHDM-1 has considerable potential as a treatment for autoimmune diseases
A Cluster Randomised Trial Introducing Rapid Diagnostic Tests into Registered Drug Shops in Uganda: Impact on Appropriate Treatment of Malaria
Background: Inappropriate treatment of malaria is widely reported particularly in areas where there is poor access to health facilities and self-treatment of fevers with anti-malarial drugs bought in shops is the most common form of care-seeking. The main objective of the study was to examine the impact of introducing rapid diagnostic tests for malaria (mRDTs) in registered drug shops in Uganda, with the aim to increase appropriate treatment of malaria with artemisinin-based combination therapy (ACT) in patients seeking treatment for fever in drug shops. Methods: A cluster-randomized trial of introducing mRDTs in registered drug shops was implemented in 20 geographical clusters of drug shops in Mukono district, central Uganda. Ten clusters were randomly allocated to the intervention (diagnostic confirmation of malaria by mRDT followed by ACT) and ten clusters to the control arm (presumptive treatment of fevers with ACT). Treatment decisions by providers were validated by microscopy on a reference blood slide collected at the time of consultation. The primary outcome was the proportion of febrile patients receiving appropriate treatment with ACT defined as: malaria patients with microscopically-confirmed presence of parasites in a peripheral blood smear receiving ACT or rectal artesunate, and patients with no malaria parasites not given ACT. Findings: A total of 15,517 eligible patients (8672 intervention and 6845 control) received treatment for fever between January-December 2011. The proportion of febrile patients who received appropriate ACT treatment was 72·9% versus 33·7% in the control arm; a difference of 36·1% (95% CI: 21·3 – 50·9), p<0·001. The majority of patients with fever in the intervention arm accepted to purchase an mRDT (97·8%), of whom 58·5% tested mRDT-positive. Drug shop vendors adhered to the mRDT results, reducing over-treatment of malaria by 72·6% (95% CI: 46·7– 98·4), p<0·001) compared to drug shop vendors using presumptive diagnosis (control arm). Conclusion: Diagnostic testing with mRDTs compared to presumptive treatment of fevers implemented in registered drug shops substantially improved appropriate treatment of malaria with ACT
Cost-Effectiveness of Pooled Nucleic Acid Amplification Testing for Acute HIV Infection after Third-Generation HIV Antibody Screening and Rapid Testing in the United States: A Comparison of Three Public Health Settings
Angela Hutchinson and colleagues conducted a cost-effectiveness analysis of pooled nucleic acid amplification testing following HIV testing and show that it is not cost-effective at recommended antibody testing intervals for high-risk persons except in very high-incidence settings
Brain and Spinal Cord Interaction: Protective Effects of Exercise Prior to Spinal Cord Injury
We have investigated the effects of a spinal cord injury on the brain and spinal cord, and whether exercise provided before the injury could organize a protective reaction across the neuroaxis. Animals were exposed to 21 days of voluntary exercise, followed by a full spinal transection (T7–T9) and sacrificed two days later. Here we show that the effects of spinal cord injury go beyond the spinal cord itself and influence the molecular substrates of synaptic plasticity and learning in the brain. The injury reduced BDNF levels in the hippocampus in conjunction with the activated forms of p-synapsin I, p-CREB and p-CaMK II, while exercise prior to injury prevented these reductions. Similar effects of the injury were observed in the lumbar enlargement region of the spinal cord, where exercise prevented the reductions in BDNF, and p-CREB. Furthermore, the response of the hippocampus to the spinal lesion appeared to be coordinated to that of the spinal cord, as evidenced by corresponding injury-related changes in BDNF levels in the brain and spinal cord. These results provide an indication for the increased vulnerability of brain centers after spinal cord injury. These findings also imply that the level of chronic activity prior to a spinal cord injury could determine the level of sensory-motor and cognitive recovery following the injury. In particular, exercise prior to the injury onset appears to foster protective mechanisms in the brain and spinal cord
Conceptualizing pathways linking women's empowerment and prematurity in developing countries.
BackgroundGlobally, prematurity is the leading cause of death in children under the age of 5. Many efforts have focused on clinical approaches to improve the survival of premature babies. There is a need, however, to explore psychosocial, sociocultural, economic, and other factors as potential mechanisms to reduce the burden of prematurity. Women's empowerment may be a catalyst for moving the needle in this direction. The goal of this paper is to examine links between women's empowerment and prematurity in developing settings. We propose a conceptual model that shows pathways by which women's empowerment can affect prematurity and review and summarize the literature supporting the relationships we posit. We also suggest future directions for research on women's empowerment and prematurity.MethodsThe key words we used for empowerment in the search were "empowerment," "women's status," "autonomy," and "decision-making," and for prematurity we used "preterm," "premature," and "prematurity." We did not use date, language, and regional restrictions. The search was done in PubMed, Population Information Online (POPLINE), and Web of Science. We selected intervening factors-factors that could potentially mediate the relationship between empowerment and prematurity-based on reviews of the risk factors and interventions to address prematurity and the determinants of those factors.ResultsThere is limited evidence supporting a direct link between women's empowerment and prematurity. However, there is evidence linking several dimensions of empowerment to factors known to be associated with prematurity and outcomes for premature babies. Our review of the literature shows that women's empowerment may reduce prematurity by (1) preventing early marriage and promoting family planning, which will delay age at first pregnancy and increase interpregnancy intervals; (2) improving women's nutritional status; (3) reducing domestic violence and other stressors to improve psychological health; and (4) improving access to and receipt of recommended health services during pregnancy and delivery to help prevent prematurity and improve survival of premature babies.ConclusionsWomen's empowerment is an important distal factor that affects prematurity through several intervening factors. Improving women's empowerment will help prevent prematurity and improve survival of preterm babies. Research to empirically show the links between women's empowerment and prematurity is however needed
Long-acting inhaled therapy (beta-agonists, anticholinergics and steroids) for COPD: a network meta-analysis.
BACKGROUND: Pharmacological therapy for chronic obstructive pulmonary disease (COPD) is aimed at relieving symptoms, improving quality of life and preventing or treating exacerbations.Treatment tends to begin with one inhaler, and additional therapies are introduced as necessary. For persistent or worsening symptoms, long-acting inhaled therapies taken once or twice daily are preferred over short-acting inhalers. Several Cochrane reviews have looked at the risks and benefits of specific long-acting inhaled therapies compared with placebo or other treatments. However for patients and clinicians, it is important to understand the merits of these treatments relative to each other, and whether a particular class of inhaled therapies is more beneficial than the others. OBJECTIVES: To assess the efficacy of treatment options for patients whose chronic obstructive pulmonary disease cannot be controlled by short-acting therapies alone. The review will not look at combination therapies usually considered later in the course of the disease.As part of this network meta-analysis, we will address the following issues.1. How does long-term efficacy compare between different pharmacological treatments for COPD?2. Are there limitations in the current evidence base that may compromise the conclusions drawn by this network meta-analysis? If so, what are the implications for future research? SEARCH METHODS: We identified randomised controlled trials (RCTs) in existing Cochrane reviews by searching the Cochrane Database of Systematic Reviews (CDSR). In addition, we ran a comprehensive citation search on the Cochrane Airways Group Register of trials (CAGR) and checked manufacturer websites and reference lists of other reviews. The most recent searches were conducted in September 2013. SELECTION CRITERIA: We included parallel-group RCTs of at least 6 months' duration recruiting people with COPD. Studies were included if they compared any of the following treatments versus any other: long-acting beta2-agonists (LABAs; formoterol, indacaterol, salmeterol); long-acting muscarinic antagonists (LAMAs; aclidinium, glycopyrronium, tiotropium); inhaled corticosteroids (ICSs; budesonide, fluticasone, mometasone); combination long-acting beta2-agonist (LABA) and inhaled corticosteroid (LABA/ICS) (formoterol/budesonide, formoterol/mometasone, salmeterol/fluticasone); and placebo. DATA COLLECTION AND ANALYSIS: We conducted a network meta-analysis using Markov chain Monte Carlo methods for two efficacy outcomes: St George's Respiratory Questionnaire (SGRQ) total score and trough forced expiratory volume in one second (FEV1). We modelled the relative effectiveness of any two treatments as a function of each treatment relative to the reference treatment (placebo). We assumed that treatment effects were similar within treatment classes (LAMA, LABA, ICS, LABA/ICS). We present estimates of class effects, variability between treatments within each class and individual treatment effects compared with every other.To justify the analyses, we assessed the trials for clinical and methodological transitivity across comparisons. We tested the robustness of our analyses by performing sensitivity analyses for lack of blinding and by considering six- and 12-month data separately. MAIN RESULTS: We identified 71 RCTs randomly assigning 73,062 people with COPD to 184 treatment arms of interest. Trials were similar with regards to methodology, inclusion and exclusion criteria and key baseline characteristics. Participants were more often male, aged in their mid sixties, with FEV1 predicted normal between 40% and 50% and with substantial smoking histories (40+ pack-years). The risk of bias was generally low, although missing information made it hard to judge risk of selection bias and selective outcome reporting. Fixed effects were used for SGRQ analyses, and random effects for Trough FEV1 analyses, based on model fit statistics and deviance information criteria (DIC). SGRQ SGRQ data were available in 42 studies (n = 54,613). At six months, 39 pairwise comparisons were made between 18 treatments in 25 studies (n = 27,024). Combination LABA/ICS was the highest ranked intervention, with a mean improvement over placebo of -3.89 units at six months (95% credible interval (CrI) -4.70 to -2.97) and -3.60 at 12 months (95% CrI -4.63 to -2.34). LAMAs and LABAs were ranked second and third at six months, with mean differences of -2.63 (95% CrI -3.53 to -1.97) and -2.29 (95% CrI -3.18 to -1.53), respectively. Inhaled corticosteroids were ranked fourth (MD -2.00, 95% CrI -3.06 to -0.87). Class differences between LABA, LAMA and ICS were less prominent at 12 months. Indacaterol and aclidinium were ranked somewhat higher than other members of their classes, and formoterol 12 mcg, budesonide 400 mcg and formoterol/mometasone combination were ranked lower within their classes. There was considerable overlap in credible intervals and rankings for both classes and individual treatments. Trough FEV1 Trough FEV1 data were available in 46 studies (n = 47,409). At six months, 41 pairwise comparisons were made between 20 treatments in 31 studies (n = 29,271). As for SGRQ, combination LABA/ICS was the highest ranked class, with a mean improvement over placebo of 133.3 mL at six months (95% CrI 100.6 to 164.0) and slightly less at 12 months (mean difference (MD) 100, 95% CrI 55.5 to 140.1). LAMAs (MD 103.5, 95% CrI 81.8 to 124.9) and LABAs (MD 99.4, 95% CrI 72.0 to 127.8) showed roughly equivalent results at six months, and ICSs were the fourth ranked class (MD 65.4, 95% CrI 33.1 to 96.9). As with SGRQ, initial differences between classes were not so prominent at 12 months. Indacaterol and salmeterol/fluticasone were ranked slightly better than others in their class, and formoterol 12, aclidinium, budesonide and formoterol/budesonide combination were ranked lower within their classes. All credible intervals for individual rankings were wide. AUTHORS' CONCLUSIONS: This network meta-analysis compares four different classes of long-acting inhalers for people with COPD who need more than short-acting bronchodilators. Quality of life and lung function were improved most on combination inhalers (LABA and ICS) and least on ICS alone at 6 and at 12 months. Overall LAMA and LABA inhalers had similar effects, particularly at 12 months. The network has demonstrated the benefit of ICS when added to LABA for these outcomes in participants who largely had an FEV1 that was less than 50% predicted, but the additional expense of combination inhalers and any potential for increased adverse events (which has been established by other reviews) require consideration. Our findings are in keeping with current National Institute for Health and Care Excellence (NICE) guidelines
Nucleotide Binding Switches the Information Flow in Ras GTPases
The Ras superfamily comprises many guanine nucleotide-binding proteins (G proteins) that are essential to intracellular signal transduction. The guanine nucleotide-dependent intrinsic flexibility patterns of five G proteins were investigated in atomic detail through Molecular Dynamics simulations of the GDP- and GTP-bound states (SGDP and SGTP, respectively). For all the considered systems, the intrinsic flexibility of SGDP was higher than that of SGTP, suggesting that Guanine Exchange Factor (GEF) recognition and nucleotide switch require higher amplitude motions than effector recognition or GTP hydrolysis. Functional mode, dynamic domain, and interaction energy correlation analyses highlighted significant differences in the dynamics of small G proteins and Gα proteins, especially in the inactive state. Indeed, SGDP of Gαt, is characterized by a more extensive energy coupling between nucleotide binding site and distal regions involved in GEF recognition compared to small G proteins, which attenuates in the active state. Moreover, mechanically distinct domains implicated in nucleotide switch could be detected in the presence of GDP but not in the presence of GTP. Finally, in small G proteins, functional modes are more detectable in the inactive state than in the active one and involve changes in solvent exposure of two highly conserved amino acids in switches I and II involved in GEF recognition. The average solvent exposure of these amino acids correlates in turn with the rate of GDP release, suggesting for them either direct or indirect roles in the process of nucleotide switch. Collectively, nucleotide binding changes the information flow through the conserved Ras-like domain, where GDP enhances the flexibility of mechanically distinct portions involved in nucleotide switch, and favors long distance allosteric communication (in Gα proteins), compared to GTP
Activation of Akt1 accelerates carcinogen-induced tumorigenesis in mammary gland of virgin and post-lactating transgenic mice
When Does Diversity Trump Ability (and Vice Versa) in Group Decision Making? A Simulation Study
It is often unclear which factor plays a more critical role in determining a group's performance: the diversity among members of the group or their individual abilities. In this study, we addressed this “diversity vs. ability” issue in a decision-making task. We conducted three simulation studies in which we manipulated agents' individual ability (or accuracy, in the context of our investigation) and group diversity by varying (1) the heuristics agents used to search task-relevant information (i.e., cues); (2) the size of their groups; (3) how much they had learned about a good cue search order; and (4) the magnitude of errors in the information they searched. In each study, we found that a manipulation reducing agents' individual accuracy simultaneously increased their group's diversity, leading to a conflict between the two. These conflicts enabled us to identify certain conditions under which diversity trumps individual accuracy, and vice versa. Specifically, we found that individual accuracy is more important in task environments in which cues differ greatly in the quality of their information, and diversity matters more when such differences are relatively small. Changing the size of a group and the amount of learning by an agent had a limited impact on this general effect of task environment. Furthermore, we found that a group achieves its highest accuracy when there is an intermediate amount of errors in the cue information, regardless of the environment and the heuristic used, an effect that we believe has not been previously reported and warrants further investigation
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