40 research outputs found

    The copper centers of tyramine β-monooxygenase and its catalytic-site methionine variants: an X-ray absorption study

    Get PDF
    Tyramine β-monooxygenase (TBM) is a member of a family of copper monooxygenases containing two noncoupled copper centers, and includes peptidylglycine monooxygenase and dopamine β-monooxygenase. In its Cu(II) form, TBM is coordinated by two to three His residues and one to two non-His O/N ligands consistent with a [CuM(His)2(OH2)2–CuH(His)3(OH2)] formulation. Reduction to the Cu(I) state causes a change in the X-ray absorption spectroscopy (XAS) spectrum, consistent with a change to a [CuM(His)2S(Met)–CuH(His)3] environment. Lowering the pH to 4.0 results in a large increase in the intensity of the Cu(I)–S extended X-ray absorption fine structure (EXAFS) component, suggesting a tighter Cu–S bond or the coordination of an additional sulfur donor. The XAS spectra of three variants, where the CuM Met471 residue had been mutated to His, Cys, and Asp, were examined. Significant differences from the wild-type enzyme are evident in the spectra of the reduced mutants. Although the side chains of His, Cys, and Asp are expected to substitute for Met at the CuM site, the data showed identical spectra for all three reduced variants, with no evidence for coordination of residue 471. Rather, the K-edge data suggested a modest decrease in coordination number, whereas the EXAFS indicated an average of two His residues at each Cu(I) center. These data highlight the unique role of the Met residue at the CuM center, and pose interesting questions as to why replacement by the cuprophilic thiolate ligand leads to detectable activity whereas replacement by imidazole generates inactive TBM

    The effectiveness of e-& mHealth interventions to promote physical activity and healthy diets in developing countries: a systematic review

    Get PDF
    Background: Promoting physical activity and healthy eating is important to combat the unprecedented rise in NCDs in many developing countries. Using modern information-and communication technologies to deliver physical activity and diet interventions is particularly promising considering the increased proliferation of such technologies in many developing countries. The objective of this systematic review is to investigate the effectiveness of e-& mHealth interventions to promote physical activity and healthy diets in developing countries.Methods: Major databases and grey literature sources were searched to retrieve studies that quantitatively examined the effectiveness of e-& mHealth interventions on physical activity and diet outcomes in developing countries. Additional studies were retrieved through citation alerts and scientific social media allowing study inclusion until August 2016. The CONSORT checklist was used to assess the risk of bias of the included studies.Results: A total of 15 studies conducted in 13 developing countries in Europe, Africa, Latin-and South America and Asia were included in the review. The majority of studies enrolled adults who were healthy or at risk of diabetes or hypertension. The average intervention length was 6.4 months, and text messages and the Internet were the most frequently used intervention delivery channels. Risk of bias across the studies was moderate (55.7 % of the criteria fulfilled). Eleven studies reported significant positive effects of an e-& mHealth intervention on physical activity and/or diet behaviour. Respectively, 50 % and 70 % of the interventions were effective in promoting physical activity and healthy diets.Conclusions: The majority of studies demonstrated that e-& mHealth interventions were effective in promoting physical activity and healthy diets in developing countries. Future interventions should use more rigorous study designs, investigate the cost-effectiveness and reach of interventions, and focus on emerging technologies, such as smart phone apps and wearable activity trackers.Trial registration: The review protocol can be retrieved from the PROSPERO database (Registration ID: CRD42015029240)

    The effect of community groups and mobile phone messages on the prevention and control of diabetes in rural Bangladesh : study protocol for a three-arm cluster randomised controlled trial

    Get PDF
    BACKGROUND: Increasing rates of type 2 diabetes mellitus place a substantial burden on health care services, communities, families and individuals living with the disease or at risk of developing it. Estimates of the combined prevalence of intermediate hyperglycaemia and diabetes in Bangladesh vary, and can be as high as 30% of the adult population. Despite such high prevalence, awareness and control of diabetes and its risk factors are limited. Prevention and control of diabetes and its complications demand increased awareness and action of individuals and communities, with positive influences on behaviours and lifestyle choices. In this study, we will test the effect of two different interventions on diabetes occurrence and its risk factors in rural Bangladesh. METHODS/DESIGN: A three-arm cluster randomised controlled trial of mobile health (mHealth) and participatory community group interventions will be conducted in four rural upazillas in Faridpur District, Bangladesh. Ninety-six clusters (villages) will be randomised to receive either the mHealth intervention or the participatory community group intervention, or be assigned to the control arm. In the mHealth arm, enrolled individuals will receive twice-weekly voice messages sent to their mobile phone about prevention and control of diabetes. In the participatory community group arm, facilitators will initiate a series of monthly group meetings for men and women, progressing through a Participatory Learning and Action cycle whereby group members and communities identify, prioritise and tackle problems associated with diabetes and the risk of developing diabetes. Both interventions will run for 18 months. The primary outcomes of the combined prevalence of intermediate hyperglycaemia and diabetes and the cumulative 2-year incidence of diabetes among individuals identified as having intermediate hyperglycaemia at baseline will be evaluated through baseline and endline sample surveys of permanent residents aged 30 years or older in each of the study clusters. Data on blood glucose level, blood pressure, body mass index and hip-to-waist ratio will be gathered through physical measurements by trained fieldworkers. Demographic and socioeconomic data, as well as data on knowledge of diabetes, chronic disease risk factor prevalence and quality of life, will be gathered through interviews with sampled respondents. DISCUSSION: This study will increase our understanding of diabetes and other non-communicable disease burdens and risk factors in rural Bangladesh. By documenting and evaluating the delivery, impact and cost-effectiveness of participatory community groups and mobile phone voice messaging, study findings will provide evidence on how population-level strategies of community mobilisation and mHealth can be implemented to prevent and control noncommunicable diseases and risk factors in this population. TRIAL REGISTRATION: ISRCTN41083256 . Registered on 30 Mar 2016 (Retrospectively Registered). TRIAL ACRONYM: D-Magic: Diabetes Mellitus - Action through Groups or mobile Information for better Control
    corecore