761 research outputs found
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Impacts of elevated atmospheric CO₂ on nutrient content of important food crops.
One of the many ways that climate change may affect human health is by altering the nutrient content of food crops. However, previous attempts to study the effects of increased atmospheric CO2 on crop nutrition have been limited by small sample sizes and/or artificial growing conditions. Here we present data from a meta-analysis of the nutritional contents of the edible portions of 41 cultivars of six major crop species grown using free-air CO2 enrichment (FACE) technology to expose crops to ambient and elevated CO2 concentrations in otherwise normal field cultivation conditions. This data, collected across three continents, represents over ten times more data on the nutrient content of crops grown in FACE experiments than was previously available. We expect it to be deeply useful to future studies, such as efforts to understand the impacts of elevated atmospheric CO2 on crop macro- and micronutrient concentrations, or attempts to alleviate harmful effects of these changes for the billions of people who depend on these crops for essential nutrients
Impact of generic alendronate cost on the cost-effectiveness of osteoporosis screening and treatment
Introduction: Since alendronate became available in generic form in the Unites States in 2008, its price has been decreasing. The objective of this study was to investigate the impact of alendronate cost on the cost-effectiveness of osteoporosis screening and treatment in postmenopausal women. Methods: Microsimulation cost-effectiveness model of osteoporosis screening and treatment for U.S. women age 65 and older. We assumed screening initiation at age 65 with central dual-energy x-ray absorptiometry (DXA), and alendronate treatment for individuals with osteoporosis; with a comparator of "no screening" and treatment only after fracture occurrence. We evaluated annual alendronate costs of 800; outcome measures included fractures; nursing home admission; medication adverse events; death; costs; quality-adjusted life-years (QALYs); and incremental cost-effectiveness ratios (ICERs) in 2010 U.S. dollars per QALY gained. A lifetime time horizon was used, and direct costs were included. Base-case and sensitivity analyses were performed. Results: Base-case analysis results showed that at annual alendronate costs of 400 through 714 per QALY gained through 50,000/QALY at all alendronate costs evaluated. Conclusions: Osteoporosis screening followed by alendronate treatment is effective and highly cost-effective for postmenopausal women across a range of alendronate costs, and may be cost-saving at annual alendronate costs of $200 or less. © 2012 Nayak et al
The Inflammatory Response to Double Stranded DNA in Endothelial Cells Is Mediated by NFκB and TNFα
Endothelial cells represent an important barrier between the intravascular compartment and extravascular tissues, and therefore serve as key sensors, communicators, and amplifiers of danger signals in innate immunity and inflammation. Double stranded DNA (dsDNA) released from damaged host cells during injury or introduced by pathogens during infection, has emerged as a potent danger signal. While the dsDNA-mediated immune response has been extensively studied in immune cells, little is known about the direct and indirect effects of dsDNA on the vascular endothelium. In this study we show that direct dsDNA stimulation of endothelial cells induces a potent proinflammatory response as demonstrated by increased expression of ICAM1, E-selectin and VCAM1, and enhanced leukocyte adhesion. This response was dependent on the stress kinases JNK and p38 MAPK, required the activation of proinflammatory transcription factors NFκB and IRF3, and triggered the robust secretion of TNFα for sustained secondary activation of the endothelium. DNA-induced TNFα secretion proved to be essential in vivo, as mice deficient in the TNF receptor were unable to mount an acute inflammatory response to dsDNA. Our findings suggest that the endothelium plays an active role in mediating dsDNA-induced inflammatory responses, and implicate its importance in establishing an acute inflammatory response to sterile injury or systemic infection, where host or pathogen derived dsDNA may serve as a danger signal.United States. Dept. of Defense (CDMRP Predoctoral Training Award)National Institutes of Health (U.S.) (NIH BioMEMS Resource Center Grant P41 EB-002503)National Institutes of Health (U.S.) (NIH Grant RO1AI063795)Shriners Hospital for Childre
SalmoNet, an integrated network of ten Salmonella enterica strains reveals common and distinct pathways to host adaptation
Salmonella enterica is a prominent bacterial pathogen with implications on human and animal health. Salmonella serovars could be classified as gastro-intestinal or extra-intestinal. Genome-wide comparisons revealed that extra-intestinal strains are closer relatives of gastro-intestinal strains than to each other indicating a parallel evolution of this trait. Given the complexity of the differences, a systems-level comparison could reveal key mechanisms enabling extra-intestinal serovars to cause systemic infections. Accordingly, in this work, we introduce a unique resource, SalmoNet, which combines manual curation, high-throughput data and computational predictions to provide an integrated network for Salmonella at the metabolic, transcriptional regulatory and protein-protein interaction levels. SalmoNet provides the networks separately for five gastro-intestinal and five extra-intestinal strains. As a multi-layered, multi-strain database containing experimental data, SalmoNet is the first dedicated network resource for Salmonella. It comprehensively contains interactions between proteins encoded in Salmonella pathogenicity islands, as well as regulatory mechanisms of metabolic processes with the option to zoom-in and analyze the interactions at specific loci in more detail. Application of SalmoNet is not limited to strain comparisons as it also provides a Salmonella resource for biochemical network modeling, host-pathogen interaction studies, drug discovery, experimental validation of novel interactions, uncovering new pathological mechanisms from emergent properties and epidemiological studies. SalmoNet is available at http://salmonet.org
Why MSM in rural South African communities should be an HIV prevention research priority.
Research into HIV and men who have sex with men's (MSM) health in South Africa has been largely confined to the metropolitan centres. Only two studies were located making reference to MSM in rural contexts or same-sex behaviors among men in the same. There is growing recognition in South Africa that MSM are not only disproportionately affected by HIV and have been underserved by the country's national response, but that they contribute significantly to sustaining the high number of new infections recorded each year. We argue that to meet the objectives of the country's national strategic plan for HIV, STI and TB it is important we know how these behaviours may be contributing to the sustained rural HIV epidemic in the youngest age groups and determine what constitutes appropriate and feasible programmatic response that can be implemented in the country's public sector health services
BRIEF REPORT: Brief Instrument to Assess Geriatrics Knowledge of Surgical and Medical Subspecialty House Officers
Initiatives are underway to increase geriatrics training in nonprimary care disciplines. However, no validated instrument exists to measure geriatrics knowledge of house officers in surgical specialties and medical subspecialties. METHODS : A 23-item multiple-choice test emphasizing inpatient care and common geriatric syndromes was developed through expert panels and pilot testing, and administered to 305 residents and fellows at 4 institutions in surgical disciplines (25% of respondents), emergency medicine (29%), medicine subspecialties (19%), internal medicine (12%), and other disciplines (15%). RESULTS : Three items decreased internal reliability. The remaining 20 items covered 17 topic areas. Residents averaged 62% correct on the test. Internal consistency was appropriate (Cronbach's Α coefficient=0.60). Validity was supported by the use of expert panels to develop content, and by overall differences in scores by level of training ( P <.0001) and graded improvement in test performance, with 58%, 63%, 62%, and 69% correct responses among HO1, HO2, HO3, and HO4s, respectively. CONCLUSIONS : This reliable, valid measure of clinical geriatrics knowledge can be used by a wide variety of surgical and medical graduate medical education programs to guide curriculum reform or evaluate program performance to meet certification requirements. The instrument is now available on the web.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73902/1/j.1525-1497.2006.00433.x.pd
Endothelial dysfunction and diabetes: roles of hyperglycemia, impaired insulin signaling and obesity
Innate Immune Sensing of DNA
Discusses efforts to understand how DNA triggers immune responses
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Minimal regulation of platelet activity by PECAM-1
PECAM-1 is a member of the superfamily of immunoglobulins (Ig) and is expressed on platelets at moderate level. PECAM-1 has been reported to have contrasting effects on platelet activation by the collagen receptor GPVI and the integrin, αIIbβ3, even though both receptors signal through Src-kinase regulation of PLCγ2. The present study compares the role of PECAM-1 on platelet activation by these two receptors and by the lectin receptor, CLEC-2, which also signals via PLCγ2. Studies using PECAM-1 knockout-mice and cross-linking of PECAM-1 using specific antibodies demonstrated a minor inhibitory role on platelet responses to the above three receptors and also under some conditions to the G-protein agonist thrombin. The degree of inhibition was considerably less than that produced by PGI2, which elevates cAMP. There was no significant difference in thrombus formation on collagen in PECAM-1-/- platelets relative to litter-matched controls. The very weak inhibitory effect of PECAM-1 on platelet activation relative to that of PGI2 indicate that the Ig-receptor is not a major regulator of platelet activation. PECAM-1 has been reported to have contrasting effects on platelet activation. The present study demonstrates a very mild or negligible effect on platelet activation in response to stimulation by a variety of agonists, thereby questioning the physiological role of the immunoglobulin receptor as a major regulator of platelet activation
Experiences of the implementation of a tool for lifestyle intervention in primary health care: a qualitative study among managers and professional groups
<p>Abstract</p> <p>Background</p> <p>In recent years there has been increasing interest in transferring new knowledge into health care practices, a process often referred to as implementation. The various subcultures that exist among health care workers may be an obstacle in this process. The aim of this study was to explore how professional groups and managers experienced the implementation of a new tool for lifestyle intervention in primary health care (PHC). The computer-based tool was introduced with the intention of facilitating the delivery of preventive services.</p> <p>Methods</p> <p>Focus group interviews with staff and individual interviews with managers at six PHC units in the southeast of Sweden were performed 9 months after the introduction of the new working tool. Staff interviews were conducted in groups according to profession, and were analysed using manifest content analysis. Experiences and opinions from the different staff groups and from managers were analysed.</p> <p>Results</p> <p>Implementation preconditions, opinions about the lifestyle test, and opinions about usage were the main areas identified. In each of the groups, managers and professionals, factors related to the existing subcultures seemed to influence their experiences of the implementation. Managers were visionary, GPs were reluctant, nurses were open, and nurse assistants were indifferent.</p> <p>Conclusion</p> <p>This study indicates that the existing subcultures in PHC influence how the implementation of an innovation is perceived by managers and the different professionals. In PHC, an organization with several subcultures and an established hierarchical structure, an implementation strategy aimed at all groups did not seem to result in a successful uptake of the new method.</p
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