195 research outputs found
The cold origin of the warm dust around epsilon Eridani
Context: The K2V star eps Eri hosts one known inner planet, an outer Kuiper
belt analog, and an inner disk of warm dust. Spitzer/IRS measurements indicate
that the warm dust is present at distances as close as a few AU from the star.
Its origin is puzzling, since an "asteroid belt" that could produce this dust
would be unstable because of the known inner planet. Aims: Here we test the
hypothesis that the observed warm dust is generated by collisions in the outer
belt and is transported inward by Poynting-Robertson (P-R) drag and strong
stellar winds. Methods: We simulated a steady-state distribution of dust
particles outside 10AU with a collisional code and in the inner region (r<10AU)
with single-particle numerical integrations. By assuming homogeneous spherical
dust grains composed of water ice and silicate, we calculated the thermal
emission of the dust and compared it with observations. We investigated two
different orbital configurations for the inner planet inferred from RV
measurements, one with a highly eccentric orbit of e=0.7 and another one with a
moderate one of e=0.25. We also produced a simulation without a planet.
Results: Our models can reproduce the shape and magnitude of the observed SED
from mid-IR to sub-mm wavelengths, as well as the Spitzer/MIPS radial
brightness profiles. The best-fit dust composition includes both ice and
silicates. The results are similar for the two possible planetary orbits and
without a planet. Conclusions: The observed warm dust in the system can indeed
stem from the outer belt and be transported inward by P-R and stellar wind
drag. The inner planet has little effect on the distribution of dust, so that
the planetary orbit could not be constrained. Reasonable agreement between the
model and observations can only be achieved by relaxing the assumption of
purely silicate dust and assuming a mixture of silicate and ice in comparable
amounts.Comment: 9 pages, 9 figures, abstract abridge
Preliminary validation of the Yale Food Addiction Scale for Children 2.0: A dimensional approach to scoring
ObjectiveAssessment approaches for food addiction in younger samples have not been updated to reflect recently revised diagnostic approaches for addictive disorders. The aim of the current study is to develop a new dimensional approach to assess food addiction in adolescents that is psychometrically sound, developmentally appropriate, and reflective of the updated diagnostic criteria.MethodsThe dimensional Yale Food Addiction Scale for Children 2.0 (dYFASâC 2.0) and related measures were administered to 127 adolescents from the community in the United States. Endorsement rates for each question were reviewed, and the psychometric properties were evaluated.ResultsProblemâfocused symptoms had low endorsement rates and were excluded from the final version of the scale. The dYFASâC 2.0 demonstrated partial evidence for a oneâfactor structure, had good internal consistency reliability, and was positively associated with emotional eating, external eating, and body mass index (BMI). The dYFASâC 2.0 also accounted for unique variance in BMI. Unexpectedly, the dYFASâC 2.0 was positively associated with restrained eating.ConclusionsThe dYFASâC 2.0 appears to have adequate psychometric properties for assessing food addiction in community samples of adolescents. Future research should evaluate the measure in clinical samples and investigate the association between food addiction and restrained eating over the lifespan.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146644/1/erv2648.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146644/2/erv2648_am.pd
A randomized controlled trial of mycophenolate mofetil in patients with IgA nephropathy [ISRCTN62574616]
BACKGROUND: IgAN is the most common type of glomerulonephritis in the world. Between 15 and 40 percent of adults and children diagnosed with IgAN eventually progress to ESRD. Despite the need for effective treatment strategies, very few RCTs for IgAN have been performed. The most effective therapies for IgAN appear to be corticosteroids, ACEi, and FOS that contain a high concentration of omega 3 fatty acids. While ACEi and FOS are generally well tolerated with minimal side effects, the use of high dose steroids over a long course of therapy is often associated with significant morbidity. OBJECTIVE OF THE STUDY: The objective of the study is to test the hypothesis that treatment with the immunosuppressive agent, MMF, will lead to significant and sustained improvement in urinary protein excretion in patients with IgAN who have been pre-treated (and continue to be treated) with ACE(i )and FOS compared to a placebo control group of patients receiving comparable doses of ACEi and FOS without MMF. DESIGN: After a three month treatment period with the ACEi, lisinopril and the FOS, Omacor(Âź), 100 (2 Ă 50) patients with IgAN and a urinary P/C ratio â„ 0.6 (males) and â„ 0.8 (females) and an estGFR â„ 40 ml/min/1.73 m2 will be randomized to treatment with either MMF or placebo for one year. All patients will be followed off study drug for a second year, but will continue treatment with lisinopril and Omacor(Âź )for the two year duration of the study. The primary outcome measure of change in urine P/C ratio will be assessed at the end of years one and two
Pressure Ulcer and Wounds Reporting in NHS Hospitals in England Part 1: Audit of Monitoring Systems
Internationally, health-care systems have attempted to assess the scale of and demonstrate improvement in patient harms. Pressure ulcer (PU) monitoring systems have been introduced across NHS in-patient facilities in England, including the Safety Thermometer (STh) (prevalence), Incident Reporting Systems (IRS) and the Strategic Executive Information System (STEIS) for serious incidents. This is the first of two related papers considering PU monitoring systems across NHS in-patient facilities in England and focusses on a Wound Audit (PUWA) to assess the accuracy of these systems. Part 2 of this work and recommendations are reported pp *-*. The PUWA was undertaken in line with âgold-standardâ PU prevalence methods in a stratified random sample of NHS Trusts; 24/34(72.7%) invited NHS Trusts participated, from which 121 randomly selected wards and 2239 patients agreed to participate. Prevalence of existing PUs: The PUWA identified 160(7.1%) patients with an existing PU, compared to 105(4.7%) on STh. STh had a weighted sensitivity of 48.2%(95%CI 35.4%-56.7%) and weighted specificity of 99.0%(95%CI 98.99%-99.01%). Existing/healed PUs: The PUWA identified 189(8.4%) patients with an existing/healed PU compared to 135(6.0%) on IRS. IRS had an unweighted sensitivity of 53.4%(95%CI 46.3% to 60.4%) and unweighted specificity of 98.3% (95%CI 97.7% to 98.8%). 83 patients had one or more potentially serious PU on PUWA and 8(9.6%) of these patients were reported on STEIS. The results identified high levels of under-reporting for all systems and highlighted data capture challenges, including the use of clinical staff to inform national monitoring systems and the completeness of clinical records for PUs
HIV-2 interaction with cell coreceptors: amino acids within the V1/V2 region of viral envelope are determinant for CCR8, CCR5 and CXCR4 usage
© 2014 Santos-Costa et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.Background: Human immunodeficiency virus 1 and 2 (HIV-1 and HIV-2) use cellular receptors in distinct ways. Besides a more promiscuous usage of coreceptors by HIV-2 and a more frequent detection of CD4-independent HIV-2 isolates, we have previously identified two HIV-2 isolates (HIV-2MIC97 and HIV-2MJC97) that do not use the two major HIV coreceptors: CCR5 and CXCR4. All these features suggest that in HIV-2 the Env glycoprotein subunits may have a different structural organization enabling distinct - although probably less efficient - interactions with cellular receptors.
Results: By infectivity assays using GHOST cell line expressing CD4 and CCR8 and blocking experiments using CCR8-specific ligand, I-309, we show that efficient replication of HIV-2MIC97 and HIV-2MJC97 requires the presence of CCR8 at plasma cell membrane. Additionally, we disclosed the determinants of chemokine receptor usage at the molecular level, and deciphered the amino acids involved in the usage of CCR8 (R8 phenotype) and in the switch from CCR8 to CCR5 or to CCR5/CXCR4 usage (R5 or R5X4 phenotype). The data obtained from site-directed mutagenesis clearly indicates that the main genetic determinants of coreceptor tropism are located within the V1/V2 region of Env surface glycoprotein of these two viruses.
Conclusions: We conclude that a viral population able to use CCR8 and unable to infect CCR5 or CXCR4-positive cells, may exist in some HIV-2 infected individuals during an undefined time period, in the course of the asymptomatic stage of infection. This suggests that in vivo alternate molecules might contribute to HIV infection of natural target cells, at least under certain circumstances. Furthermore we provide direct and unequivocal evidence that the usage of CCR8 and the switch from R8 to R5 or R5X4 phenotype is determined by amino acids located in the base and tip of V1 and V2 loops of HIV-2 Env surface glycoprotein.This work was supported by grants from: Fundação para a CiĂȘncia e Tecnologia (FCT; PPCDT/SAU-IMI/55726/2004); Fundação para a CiĂȘncia e Tecnologia and MinistĂ©rio da SaĂșde de Portugal (VIH/SAU/0006/2011); and from Gilead Sciences Portugal (Programa Gilead GĂ©nese).info:eu-repo/semantics/publishedVersio
Pressure UlceR Programme Of reSEarch (PURPOSE): using mixed methods (systematic reviews, prospective cohort, case study, consensus and psychometrics) to identify patient and organisational risk, develop a risk assessment tool and patient-reported outcome Quality of Life and Health Utility measures
Background: The Pressure UlceR Programme Of reSEarch (PURPOSE) consisted of two themes. Theme 1 focused on improving our understanding of individualsâ and organisational risk factors and on improving the quality of risk assessments (work packages 1â3) and theme 2 focused on developing patient-reported outcome measures (work packages 4 and 5). Methods: The programme comprised 21 individual pieces of work. Pain: (1) multicentre pain prevalence study in acute hospitals, (2) multicentre pain prevalence study in community localities incorporating (3) a comparison of case-finding methods, and (4) multicentre, prospective cohort study. Severe pressure ulcers: (5) retrospective case study, (6) patient involvement workshop with the Pressure Ulcer Research Service User Network for the UK (PURSUN UK) and (7) development of root cause analysis methodology. Risk assessment: (8) systematic review, (9) consensus study, (10) conceptual framework development and theoretical causal pathway, (11) design and pretesting of draft Risk Assessment Framework and (12) field test to assess reliability, validity, data completeness and clinical usability. Quality of life: (13) conceptual framework development (systematic review, patient interviews), (14 and 15) provisional instrument development, with items generated from patient interviews [from (1) above] two systematic reviews and experts, (16) pretesting of the provisional Pressure Ulcer Quality of Life (PU-QOL) instrument using mixed methods, (17) field test 1 including (18) optimal mode of administration substudy and item reduction with testing of scale formation, acceptability, scaling assumptions, reliability and validity, and (19) field test 2 â final psychometric evaluation to test scale targeting, item response categories, item fit, response bias, acceptability, scaling assumptions, reliability and validity. Costâutility: (20) time trade-off task valuations of health states derived from selected PU-QOL items, and (21) validation of the items selected and psychometric properties of the new Pressure Ulcer Quality of Life Utility Index (PUQOL-UI). Key findings:Pain: prevalence studies â hospital and community patients experience both pressure area-related and pressure ulcer pain; pain cohort study â indicates that pain is independently predictive of category 2 (and above) pressure ulcer development. Severe pressure ulcers: these were more likely to develop in contexts in which clinicians failed to listen to patients/carers or recognise/respond to high risk or the presence of an existing pressure ulcer and services were not effectively co-ordinated; service users found the interactive workshop format valuable; including novel components (interviews with patients and carers) in root cause analysis improves the quality of the insights captured. Risk assessment: we developed a Pressure Ulcer Risk Assessment Framework, the PURPOSE-T, incorporating the Minimum Data Set, a screening stage, a full assessment stage, use of colour to support decision-making, and decision pathways that make a clear distinction between patients with an existing pressure ulcer(s) (or scarring from previous ulcers) who require secondary prevention and treatment and those at risk who require primary prevention (http://medhealth.leeds.ac.uk/accesspurposet). Quality of life: the final PU-QOL instrument consists of 10 scales to measure pain, exudate, odour, sleep, vitality, mobility/movement, daily activities, emotional well-being, self-consciousness and appearance, and participation (http://medhealth.leeds.ac.uk/puqol-ques). Costâutility: seven items were selected from the PU-QOL instrument for inclusion in the PUQOL-UI (http://medhealth.leeds.ac.uk/puqol-ui); secondary study analysis indicated that item selection for the PUQOL-UI was appropriate and that the index was acceptable to patients and had adequate levels of validity. Conclusions: The PURPOSE programme has provided important insights for pressure ulcer prevention and treatment and involvement of service users in research and development, with implications for patient and public involvement, clinical practice, quality/safety/health service management and research including replication of the pain risk factor study, work exploring âbest practiceâ settings, the impact of including skin status as an indicator for escalation of preventative interventions, further psychometric evaluation of PU-QOL and PUQOL-UI the measurement of âdisease attribution.â Funding: The National Institute for Health Research Programme Grants for Applied Research programme
Developing Behavior Change Interventions
Peer reviewe
- âŠ