215 research outputs found
Redox, haem and CO in enzymatic catalysis and regulation
The present paper describes general principles of redox catalysis and redox regulation in two diverse systems. The first is microbial metabolism of CO by the WoodâLjungdahl pathway, which involves the conversion of CO or H2/CO2 into acetyl-CoA, which then serves as a source of ATP and cell carbon. The focus is on two enzymes that make and utilize CO, CODH (carbon monoxide dehydrogenase) and ACS (acetyl-CoA synthase). In this pathway, CODH converts CO2 into CO and ACS generates acetyl-CoA in a reaction involving Ni·CO, methyl-Ni and acetyl-Ni as catalytic intermediates. A 70 Ă
(1 Ă
=0.1 nm) channel guides CO, generated at the active site of CODH, to a CO âcageâ near the ACS active site to sequester this reactive species and assure its rapid availability to participate in a kinetically coupled reaction with an unstable Ni(I) state that was recently trapped by photolytic, rapid kinetic and spectroscopic studies. The present paper also describes studies of two haem-regulated systems that involve a principle of metabolic regulation interlinking redox, haem and CO. Recent studies with HO2 (haem oxygenase-2), a K+ ion channel (the BK channel) and a nuclear receptor (Rev-Erb) demonstrate that this mode of regulation involves a thiolâdisulfide redox switch that regulates haem binding and that gas signalling molecules (CO and NO) modulate the effect of haem.National Institutes of Health (U.S.) (NIH grant GM69857)National Institutes of Health (U.S.) (NIH grant GM39451)National Institutes of Health (U.S.) (NIH grant HL 102662)National Institutes of Health (U.S.) (NIH grant GM65440)National Institutes of Health (U.S.) (NIH grant GM48242)National Institutes of Health (U.S.) (NIH grant Y1-GM- 1104)National Institutes of Health (U.S.) (NIH grant GM065318)National Institutes of Health (U.S.) (NIH grant AG027349)National Science Foundation (U.S.) (grant number CHE-0745353)United States. Dept. of Energy. Office of Biological and Environmental ResearchHoward Hughes Medical Institute (Investigator
IMPLEmenting a clinical practice guideline for acute low back pain evidence-based manageMENT in general practice (IMPLEMENT) : cluster randomised controlled trial study protocol
Background: Evidence generated from reliable research is not frequently implemented into clinical practice. Evidence-based clinical practice guidelines are a potential vehicle to achieve this. A recent systematic review of implementation strategies of guideline dissemination concluded that there was a lack of evidence regarding effective strategies to promote the uptake of guidelines. Recommendations from this review, and other studies, have suggested the use of interventions that are theoretically based because these may be more effective than those that are not. An evidencebased clinical practice guideline for the management of acute low back pain was recently developed in Australia. This provides an opportunity to develop and test a theory-based implementation intervention for a condition which is common, has a high burden, and for which there is an evidence-practice gap in the primary care setting. Aim: This study aims to test the effectiveness of a theory-based intervention for implementing a clinical practice guideline for acute low back pain in general practice in Victoria, Australia. Specifically, our primary objectives are to establish if the intervention is effective in reducing the percentage of patients who are referred for a plain x-ray, and improving mean level of disability for patients three months post-consultation. Methods/Design: This study protocol describes the details of a cluster randomised controlled trial. Ninety-two general practices (clusters), which include at least one consenting general practitioner, will be randomised to an intervention or control arm using restricted randomisation. Patients aged 18 years or older who visit a participating practitioner for acute non-specific low back pain of less than three months duration will be eligible for inclusion. An average of twenty-five patients per general practice will be recruited, providing a total of 2,300 patient participants. General practitioners in the control arm will receive access to the guideline using the existing dissemination strategy. Practitioners in the intervention arm will be invited to participate in facilitated face-to-face workshops that have been underpinned by behavioural theory. Investigators (not involved in the delivery of the intervention), patients, outcome assessors and the study statistician will be blinded to group allocation. Trial registration: Australian New Zealand Clinical Trials Registry ACTRN012606000098538 (date registered 14/03/2006).The trial is funded by the NHMRC by way of a Primary Health Care Project Grant (334060). JF has 50% of her time funded by the Chief Scientist Office3/2006). of the Scottish Government Health Directorate and 50% by the University of Aberdeen. PK is supported by a NHMRC Health Professional Fellowship (384366) and RB by a NHMRC Practitioner Fellowship (334010). JG holds a Canada Research Chair in Health Knowledge Transfer and Uptake. All other authors are funded by their own institutions
Association of Accelerometry-Measured Physical Activity and Cardiovascular Events in Mobility-Limited Older Adults: The LIFE (Lifestyle Interventions and Independence for Elders) Study.
BACKGROUND:Data are sparse regarding the value of physical activity (PA) surveillance among older adults-particularly among those with mobility limitations. The objective of this study was to examine longitudinal associations between objectively measured daily PA and the incidence of cardiovascular events among older adults in the LIFE (Lifestyle Interventions and Independence for Elders) study. METHODS AND RESULTS:Cardiovascular events were adjudicated based on medical records review, and cardiovascular risk factors were controlled for in the analysis. Home-based activity data were collected by hip-worn accelerometers at baseline and at 6, 12, and 24 months postrandomization to either a physical activity or health education intervention. LIFE study participants (n=1590; age 78.9±5.2 [SD] years; 67.2% women) at baseline had an 11% lower incidence of experiencing a subsequent cardiovascular event per 500 steps taken per day based on activity data (hazard ratio, 0.89; 95% confidence interval, 0.84-0.96; P=0.001). At baseline, every 30 minutes spent performing activities â„500 counts per minute (hazard ratio, 0.75; confidence interval, 0.65-0.89 [P=0.001]) were also associated with a lower incidence of cardiovascular events. Throughout follow-up (6, 12, and 24 months), both the number of steps per day (per 500 steps; hazard ratio, 0.90, confidence interval, 0.85-0.96 [P=0.001]) and duration of activity â„500 counts per minute (per 30 minutes; hazard ratio, 0.76; confidence interval, 0.63-0.90 [P=0.002]) were significantly associated with lower cardiovascular event rates. CONCLUSIONS:Objective measurements of physical activity via accelerometry were associated with cardiovascular events among older adults with limited mobility (summary score >10 on the Short Physical Performance Battery) both using baseline and longitudinal data. CLINICAL TRIAL REGISTRATION:URL: http://www.clinicaltrials.gov. Unique identifier: NCT01072500
Risk factors for episodes of back pain in emerging adults. A systematic review
BACKGROUND AND OBJECTIVE: The transition from adolescence to adulthood is a sensitive period in life for health outcomes, including back pain. The objective was to synthesize evidence on risk factors for new episodes of back pain in emerging adults (18-29 years). METHODS: The protocol was registered in PROSPERO (CRD42016046635). We searched Medline; EMBASE; AMED and other databases up to September 2018 for prospective cohort studies that estimated the association between risk factor(s) and self-reported back pain. Risk factors could be measured before or during the age range 18-29 years, and back pain could be measured during or after this age range, with at least 12 months between assessments. Risk factors assessed in â„3 studies were summarized. Risk of bias was assessed using a 6-item checklist. RESULTS: Forty-nine studies were included with more than 150 different risk factors studied. Nine studies had low risk of bias, 26 had moderate, and 14 had high risk of bias. Age, sex, height, body mass index (BMI), smoking, physical activity level, a history of back pain, job satisfaction and structural imaging findings were investigated in 3 or more studies. History of back pain was the only risk factor consistently associated with back pain after adjustment (9 studies). CONCLUSION: There is moderate quality evidence that a history of back pain is a risk factor for back pain. There are inconsistent associations for age, sex, height, BMI, smoking, and activity level. No associations were found between job satisfaction and structural imaging findings and back pain. This article is protected by copyright. All rights reserved
A participatory action research approach to strengthening health managersâ capacity at district level in Eastern Uganda
BACKGROUND: Many approaches to improving health managersâ capacity in poor countries, particularly those pursued
by external agencies, employ non-participatory approaches and often seek to circumvent (rather than strengthen)
weak public management structures. This limits opportunities for strengthening local health managersâ capacity,
improving resource utilisation and enhancing service delivery. This study explored the contribution of a participatory
action research approach to strengthening health managersâ capacity in Eastern Uganda.
METHODS: This was a qualitative study that used open-ended key informant interviews, combined with review of
meeting minutes and observations to collect data. Both inductive and deductive thematic analysis was undertaken.
The Competing Values Framework of organisational management functions guided the deductive process of analysis
and the interpretation of the findings. The framework builds on four earlier models of management and regards them
as complementary rather than conflicting, and identifies four managersâ capacities (collaborate, create, compete and
control) by categorising them along two axes, one contrasting flexibility versus control and the other internal versus
external organisational focus.
RESULTS: The findings indicate that the participatory action research approach enhanced health managersâ capacity to
collaborate with others, be creative, attain goals and review progress. The enablers included expanded interaction spaces,
encouragement of flexibility, empowerment of local managers, and the promotion of reflection and accountability. Tension
and conflict across different management functions was apparent; for example, while there was a need to collaborate,
maintaining control over processes was also needed. These tensions meant that managers needed to learn to
simultaneously draw upon and use different capacities as reflected by the Competing Values Framework in
order to maximise their effectiveness.
CONCLUSIONS: Improved health manager capacity is essential if sustained improvements in health outcomes in lowincome
countries are to be attained. The expansion of interaction spaces, encouragement of flexibility, empowerment of
local managers, and the promotion of reflection and accountability were the key means by which participatory action
research strengthened health managersâ capacity. The participatory approach to implementation therefore
created opportunities to strengthen health managersâ capacity
Scientists' Warning to Humanity on Threats to Indigenous and Local Knowledge Systems
The knowledge systems and practices of Indigenous Peoples and local communities play critical roles in safeguarding the biological and cultural diversity of our planet. Globalization, government policies, capitalism, colonialism, and other rapid social-ecological changes threaten the relationships between Indigenous Peoples and local communities and their environments, thereby challenging the continuity and dynamism of Indigenous and Local Knowledge (ILK). In this article, we contribute to the âWorld Scientists' Warning to Humanity,â issued by the Alliance of World Scientists, by exploring opportunities for sustaining ILK systems on behalf of the future stewardship of our planet. Our warning raises the alarm about the pervasive and ubiquitous erosion of knowledge and practice and the social and ecological consequences of this erosion. While ILK systems can be adaptable and resilient, the foundations of these knowledge systems are compromised by ongoing suppression, misrepresentation, appropriation, assimilation, disconnection, and destruction of biocultural heritage. Three case studies illustrate these processes and how protecting ILK is central to biocultural conservation. We conclude with 15 recommendations that call for the recognition and support of Indigenous Peoples and local communities and their knowledge systems. Enacting these recommendations will entail a transformative and sustained shift in how ILK systems, their knowledge holders, and their multiple expressions in lands and waters are recognized, affirmed, and valued. We appeal for urgent action to support the efforts of Indigenous Peoples and local communities around the world to maintain their knowledge systems, languages, stewardship rights, ties to lands and waters, and the biocultural integrity of their territoriesâon which we all depend.Peer reviewe
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