174 research outputs found

    The Allometry of Host-Pathogen Interactions

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    Understanding the mechanisms that control rates of disease progression in humans and other species is an important area of research relevant to epidemiology and to translating studies in small laboratory animals to humans. Body size and metabolic rate influence a great number of biological rates and times. We hypothesize that body size and metabolic rate affect rates of pathogenesis, specifically the times between infection and first symptoms or death.We conducted a literature search to find estimates of the time from infection to first symptoms (t(S)) and to death (t(D)) for five pathogens infecting a variety of bird and mammal hosts. A broad sampling of diseases (1 bacterial, 1 prion, 3 viruses) indicates that pathogenesis is controlled by the scaling of host metabolism. We find that the time for symptoms to appear is a constant fraction of time to death in all but one disease. Our findings also predict that many population-level attributes of disease dynamics are likely to be expressed as dimensionless quantities that are independent of host body size.Our results show that much variability in host pathogenesis can be described by simple power functions consistent with the scaling of host metabolic rate. Assessing how disease progression is controlled by geometric relationships will be important for future research. To our knowledge this is the first study to report the allometric scaling of host/pathogen interactions

    Use of intervention mapping to adapt a health behavior change intervention for endometrial cancer survivors: The shape-up following cancer treatment program

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    Background: About 80% of endometrial cancer survivors (ECS) are overweight or obese and have sedentary behaviors. Lifestyle behavior interventions are promising for improving dietary and physical activity behaviors, but the constructs associated with their effectiveness are often inadequately reported. The aim of this study was to systematically adapt an evidence-based behavior change program to improve healthy lifestyle behaviors in ECS. Methods: Following a review of the literature, focus groups and interviews were conducted with ECS (n = 16). An intervention mapping protocol was used for the program adaptation, which consisted of six steps: a needs assessment, formulation of matrices of change objectives, selection of theoretical methods and practical applications, program production, adoption and implementation planning, and evaluation planning. Social Cognitive Theory and Control Theory guided the adaptation of the intervention. Results: The process consisted of eight 90-min group sessions focusing on shaping outcome expectations, knowledge, self-efficacy, and goals about healthy eating and physical activity. The adapted performance objectives included establishment of regular eating, balanced diet, and portion sizes, reduction in sedentary behaviors, increase in lifestyle and organized activities, formulation of a discrepancy-reducing feedback loop for all above behaviors, and trigger management. Information on managing fatigue and bowel issues unique to ECS were added. Conclusions: Systematic intervention mapping provided a framework to design a cancer survivor-centered lifestyle intervention. ECS welcomed the intervention and provided essential feedback for its adaptation. The program has been evaluated through a randomized controlled trial

    Successful implementation of new technologies in nursing care: a questionnaire survey of nurse-users

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    <p>Abstract</p> <p>Background</p> <p>A growing number of new technologies are becoming available within nursing care that can improve the quality of care, reduce costs, or enhance working conditions. However, such effects can only be achieved if technologies are used as intended. The aim of this study is to gain a better understanding of determinants influencing the success of the introduction of new technologies as perceived by nursing staff.</p> <p>Methods</p> <p>The study population is a nationally representative research sample of nursing staff (further referred to as the Nursing Staff Panel), of whom 685 (67%) completed a survey questionnaire about their experiences with recently introduced technologies. Participants were working in Dutch hospitals, psychiatric organizations, care organizations for mentally disabled people, home care organizations, nursing homes or homes for the elderly.</p> <p>Results</p> <p>Half of the respondents were confronted with the introduction of a new technology in the last three years. Only half of these rated the introduction of the technology as positive.</p> <p>The factors most frequently mentioned as impeding actual use were related to the (kind of) technology itself, such as malfunctioning, ease of use, relevance for patients, and risks to patients. Furthermore nursing staff stress the importance of an adequate innovation strategy.</p> <p>Conclusions</p> <p>A prerequisite for the successful introduction of new technologies is to analyse determinants that may impede or enhance the introduction among potential users. For technological innovations special attention has to be paid to the (perceived) characteristics of the technology itself.</p

    Nucleosome mobilization by ISW2 requires the concerted action of the ATPase and SLIDE domains

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    The ISWI family of ATP-dependent chromatin remodelers represses transcription by changing nucleosome positioning. The interactions with extranucleosomal DNA and the requirement of a minimal length of extranucleosomal DNA by ISWI mediate the spacing of nucleosomes. ISW2 from Saccharomyces cerevisiae, a member of the ISWI family, has a conserved domain called SLIDE (SANT-like ISWI domain), whose binding to extranucleosomal DNA ~19 bp from the edge of nucleosomes is required for efficiently pushing DNA into nucleosomes and maintaining the unidirectional movement of nucleosomes, as reported here. Loss of SLIDE binding does not perturb ATPase domain binding to the SHL2 site of nucleosomes or its initial movement of DNA inside of nucleosomes. ISW2 has therefore two distinct roles in mobilizing nucleosomes, with the ATPase domain translocating and moving DNA inside nucleosomes, and the SLIDE domain facilitating the entry of linker DNA into nucleosomes

    General practitioners' views and experiences of counselling for physical activity through the New Zealand Green Prescription program

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    Background: Regular physical activity is beneficial in both the prevention and management of chronic health conditions. A large proportion of adult New Zealanders, however, are insufficiently active. To help increase population levels of physical activity in New Zealand the Green Prescription, a primary care physical activity scripting program, was developed. The primary aim of this study was to identify why general practitioners (GPs) counsel for physical activity and administer Green Prescriptions. A secondary aim was to examine GPs' views and experiences of Green Prescription counselling for the management of depression. Methods. Individual face-to-face interviews were conducted with 15 GPs. All interviews were audio-taped and transcribed. Data were analysed using an inductive thematic approach. Results: Several themes and sub-themes emerged from the data. Notably, GPs counselled for physical activity and prescribed Green Prescriptions for both primary preventive (e.g., weight control) and secondary management (e.g., diabetes management) purposes. GPs reported the benefits of the Green Prescription centred around two main themes: (i) a non-medication approach to a healthier lifestyle and (ii) the support benefits of physical activity. Time constraints within the consultation was the only main theme that emerged regarding the barriers GPs perceived to Green Prescription use. Physical activity in general, and physical activity prescribed through the Green Prescription, were also viewed by GPs as beneficial for the management of depression. Conclusions: The results of this study suggest that New Zealand GPs view the Green Prescription program as beneficial for their patients with pre-existing conditions and/or weight problems. While this is encouraging, the Green Prescription may also be used to promote physical activity in currently healthy but low-active and sedentary individuals. Such individuals are currently disease free, but are at risk for future health-related problems because of their inactive lifestyle. It is recommended that time constraints of the consultation in regard to administering Green Prescriptions could be dealt with by delegating the more time consuming tasks to the patient support counsellors that support the Green Prescription program, and having practice nurses assist in the administration of Green Prescriptions. Green Prescription counselling in conjunction with antidepressant medication may be beneficial for the management of depression and warrants further research

    A Multigenerational View of Inequality

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    The study of intergenerational mobility and most population research are governed by a two-generation (parent-to-offspring) view of intergenerational influence, to the neglect of the effects of grandparents and other ancestors and nonresident contemporary kin. While appropriate for some populations in some periods, this perspective may omit important sources of intergenerational continuity of family-based social inequality. Social institutions, which transcend individual lives, help support multigenerational influence, particularly at the extreme top and bottom of the social hierarchy, but to some extent in the middle as well. Multigenerational influence also works through demographic processes because families influence subsequent generations through differential fertility and survival, migration, and marriage patterns, as well as through direct transmission of socioeconomic rewards, statuses, and positions. Future research should attend more closely to multigenerational effects; to the tandem nature of demographic and socioeconomic reproduction; and to data, measures, and models that transcend coresident nuclear families

    Illness management and recovery (IMR) in Danish community mental health centres

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    <p>Abstract</p> <p>Background</p> <p>Schizophrenia and bipolar disorder are severe mental illnesses that can have a significant disabling impact on the lives of people. Psychosocial interventions that stress hope and recovery as a part of a multi-dimensional approach are possibly indicated to support people with severe mental illness in facilitating recovery. Illness Management and Recovery (IMR) is a curriculum-based psychosocial intervention designed as structured program with a recovery-oriented approach. The aim of IMR is to rehabilitate people with severe mental illnesses by helping them acquire knowledge and skills in managing their illness and achieve personal recovery goals. Previous randomised clinical trials indicate that IMR can be implemented with a good effect and a high fidelity though further trials are crucial to demonstrate the potential effectiveness of IMR.</p> <p>Methods/Design</p> <p>The trial design is a randomised, assessor-blinded, multi-centre, clinical trial of the IMR program compared with treatment as usual for 200 participants diagnosed with schizophrenia or bipolar disorder under the care of two community mental health centres in the Capital Region of Denmark. The primary outcome is level of functioning at the end of treatment. The secondary outcomes are disease symptoms; use of alcohol/drugs; individual meaning of recovery; hope; hospital admissions and out-patient psychiatric treatment at the end of treatment and the abovementioned and level of functioning at follow-up 21 months after baseline.</p> <p>Discussion</p> <p>If the results of this trial show IMR to be effective these positive results will strengthen the evidence of IMR as an effective comprehensive psychosocial intervention with a recovery-oriented approach for people with severe mental illness. This will have significant implications for the treatment and recovery of people with severe mental illness.</p> <p>Trial registration</p> <p>Registration number <a href="http://www.clinicaltrials.gov/ct2/show/NCT01361698">NCT01361698</a>.</p

    Transport of Anthocyanins and other Flavonoids by the Arabidopsis ATP-Binding Cassette Transporter AtABCC2

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    Flavonoids have important developmental, physiological, and ecological roles in plants and are primarily stored in the large central vacuole. Here we show that both an ATP-binding cassette (ABC) transporter(s) and an H+-antiporter(s) are involved in the uptake of cyanidin 3-O-glucoside (C3G) by Arabidopsis vacuolar membrane-enriched vesicles. We also demonstrate that vesicles isolated from yeast expressing the ABC protein AtABCC2 are capable of MgATP-dependent uptake of C3G and other anthocyanins. The uptake of C3G by AtABCC2 depended on the co-transport of glutathione (GSH). C3G was not altered during transport and a GSH conjugate was not formed. Vesicles from yeast expressing AtABCC2 also transported flavone and flavonol glucosides. We performed ligand docking studies to a homology model of AtABCC2 and probed the putative binding sites of C3G and GSH through site-directed mutagenesis and functional studies. These studies identified residues important for substrate recognition and transport activity in AtABCC2, and suggest that C3G and GSH bind closely, mutually enhancing each other’s binding. In conclusion, we suggest that AtABCC2 along with possibly other ABCC proteins are involved in the vacuolar transport of anthocyanins and other flavonoids in the vegetative tissue of Arabidopsis
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