228 research outputs found
Homology Modeling and Molecular Docking of Antagonists to Class B G-Protein Coupled Receptor Pituitary Adenylate Cyclase Type 1 (PAC1R)
Recent studies have identified the Class B g-protein coupled receptor (GPCR) pituitary adenylate cyclase activating polypeptide type 1 (PAC1R) as a key component in physiological stress management. Over-activity of neurological stress response systems due to prolonged or extreme exposure to traumatic events has led researchers to investigate PAC1R inhibition as a possible treatment for anxiety disorders such as post-traumatic stress disorder (PTSD). In 2008, Beebe and coworkers identified two such small molecule hydrazide antagonists and a general pharmacaphore for PAC1R inhibition. However, a relative dearth of information about Class B GPCRs in general, and PAC1R in specific, has significantly hindered progress toward the development of small molecule antagonists of PAC1R. The recent crystallization of the homologically similar glucagon receptor (GCGR) by Siu and coworkers in 2013, also a Class B receptor, has provided an experimentally resolved template from which to base computationally derived models of PAC1R.
Initially, this research was focused towards synthesizing small molecule antagonists for PAC1R which were to be biologically screened via a qualitative western blot assay followed by a radioisotope binding assay for those hydrazides exhibiting down-stream signaling inhibitory capabilities. However, the resolution of the GCGR crystal structure shifted research objectives towards developing a homology model of PAC1R and evaluating that computationally created model with Beebe\u27s known small molecule antagonists. Created using academic versions of on-line resources including UniProtKB, Swiss-Model and Maestro, a homology model for PAC1R is presented here. The model is validated and evaluated for the presence of conserved Class B GPCR residues and motifs, including expected disulfide bridges, a conserved tyrosine residue, a GWGxP motif, a conserved glutamic acid residue and the extension of the transmembrane helix 1 (TM1) into the extra-cellular domain.
Having determined this virtual PAC1R an acceptable model, ligand docking studies of known antagonists to the receptor were undertaken using AutoDock Vina in conjunction with AutoDock Tools and PyMol. Computational docking results were evaluated via comparison of theoretical binding affinity results to Beebe\u27s experimental data. Based on hydrogen bonding capabilities, several residues possibly key to the ligand-receptor binding complex are identified and include ASN 240, TYR 241 and HIST 365. Although the docking software does not identify non-bonding interactions other than hydrogen-bonding, the roles of additional proposed binding pocket residues are discussed in terms of hydrophobic interactions, Ï-Ï interactions and halogen bonding. These residues include TYR 161, PHE 196, VAL 203, PHE 204, ILE 209, LEU 210, VAL 237, TRP 297, PHE 362 and LEU 386. Although theoretical in nature, this reported homology modeling and docking exercise details a proposed binding site that may potentially further the development of drugs designed for the treatment of PTSD
Clinical trial metadata:Defining and extracting metadata on the design, conduct, results and costs of 125 randomised clinical trials funded by the National Institute for Health Research Health Technology Assessment programme
Background: Â By 2011, the Health Technology Assessment (HTA) programme had published the results of over 100 trials with another 220 in progress. The aim of the project was to develop and pilot âmetadataâ on clinical trials funded by the HTA programme. Â Objectives: The aim of the project was to develop and pilot questions describing clinical trials funded by the HTA programme in terms of it meeting the needs of the NHS with scientifically robust studies. The objectives were to develop relevant classification systems and definitions for use in answering relevant questions and to assess their utility. Â Data sources: Published monographs and internal HTA documents. Â Review methods: A database was developed, âpopulatedâ using retrospective data and used to answer questions under six prespecified themes. Questions were screened for feasibility in terms of data availability and/or ease of extraction. Answers were assessed by the authors in terms of completeness, success of the classification system used and resources required. Each question was scored to be retained, amended or dropped. Â Â Results: One hundred and twenty-five randomised trials were included in the database from 109 monographs. Neither the International Standard Randomised Controlled Trial Number nor the term ârandomised trialâ in the title proved a reliable way of identifying randomised trials. Only limited data were available on how the trials aimed to meet the needs of the NHS. Most trials were shown to follow their protocols but updates were often necessary as hardly any trials recruited as planned. Details were often lacking on planned statistical analyses, but we did not have access to the relevant statistical plans. Almost all the trials reported on cost-effectiveness, often in terms of both the primary outcome and quality-adjusted life-years. The cost of trials was shown to depend on the number of centres and the duration of the trial. Of the 78 questions explored, 61 were well answered, 33 fully with 28 requiring amendment were the analysis updated. The other 17 could not be answered with readily available data. Â Limitations: The study was limited by being confined to 125 randomised trials by one funder. Â Conclusions: Metadata on randomised controlled trials can be expanded to include aspects of design, performance, results and costs. The HTA programme should continue and extend the work reported here
Mobile Technology for Empowering Health Workers in Underserved Communities: New Approaches to Facilitate the Elimination of Neglected Tropical Diseases.
BACKGROUND
As global mobile phone penetration increases, direct health information communication from hard-to-reach communities is becoming commonplace. Mobile health (mHealth) tools that enable disease control programs to benefit from this information, while simultaneously empowering community members to take control of their own health, are vital to the goal of universal health care.
OBJECTIVE
Our aim was to highlight the development of the Liverpool mHealth Suite (LMS), which has been designed to address this need and improve health services for neglected tropical diseases being targeted for global elimination, such as lymphatic filariasis.
METHODS
The LMS has two main communication approaches-short message service and mobile phone apps-to facilitate real-time mass drug administration (MDA) coverage, reporting patient numbers, managing stock levels of treatment supplies, and exchanging health information to improve the quality of care of those affected.
RESULTS
The LMS includes the MeasureSMS-MDA tool to improve drug supplies and MDA coverage rates in real-time (currently being trialed in urban Tanzania); the MeasureSMS-Morbidity tool to map morbidity, including lymphedema and hydrocele cases (initially piloted in rural Malawi and Ghana, then extended to Ethiopia, and scaled up to large urban areas in Bangladesh and Tanzania); the LyMSS-lymphedema management supply system app to improve distribution of treatments (trialed for 6 months in Malawi with positive impacts on health workers and patients); and the HealthFront app to improve education and training (in development with field trials planned).
CONCLUSIONS
The current success and scale-up of the LMS by many community health workers in rural and urban settings across Africa and Asia highlights the value of this simple and practical suite of tools that empowers local health care workers to contribute to local, national, and global elimination of disease
Wilmsâ tumour antigen 1 Immunity via DNA fusion gene vaccination in haematological malignancies by intramuscular injection followed by intramuscular electroporation: a Phase II non-randomised clinical trial (WIN)
Background: In the UK almost 7000 people are diagnosed with leukaemia each year, but despite continuing advances in diagnosis and treatment with new drugs, such as the tyrosine kinase inhibitors, the majority of these patients will eventually die from their disease. Until quite recently, the only treatment to offer the possibility of long-term disease-free survival was allogeneic stem cell transplantation. However, this carries a substantial risk of mortality and is available to only a minority of patients.Objectives: The aim of the study was to test the hypothesis that molecular and clinical responses, induced by T lymphocytes (T cells), can be predicted by increases in the number of CD8+ (cluster of differentiation 8-positive) T cells specific for the vaccine-encoded T-cell epitopes. This project also aimed to build on the established programme of deoxyribonucleic acid (DNA) fusion-gene vaccination delivered by intramuscular injection, exploiting a unique experience with electroporation, to induce durable immune responses with the aim of controlling disease by precision attack of the tumour by CD8+ T cells.Method: A non-randomised, open-label, single-dose-level Phase II clinical trial in two patient groups [chronic myeloid leukaemia (CML) and acute myeloid leukaemia (AML)] on stable doses of imatinib. Human leucocyte antigen A2-positive (HLA A2+) patients were vaccinated with two DNA vaccines: (1) p.DOMâWT1-37 (epitope sequence: VLDFAPPGA); and (2) p.DOMâWT1-126 (epitope sequence: RMFPNAPYL). The HLA A2-negative patients formed an unvaccinated control group. The sample size for the HLA A2+ group was originally determined following Simonâs optimal Phase II trial design (Simon R. Optimal two-stage designs for phase II clinical trials. Control Clin Trials 1989;10:1â10). This was changed to AâHernâs single-stage design during the course of the trial (AâHern RP. Sample size tables for single-stage phase II designs. Stat Med 2001;20:859â66), which was endorsed by the trialâs independent oversight committees.Results: The study included 12 patients with CML who were vaccinated and nine patients with CML who were unvaccinated as the control group. Both the vaccines and the electroporation were safe, with no new or unexpected toxicities. The evaluation adverse events of special interest (heart, bone marrow, renal) did not reveal safety concerns. Two BCRâABL (breakpoint cluster regionâAbelson murine leukaemia viral oncogene homolog 1) responses were observed, both of which were defined as a major response, with one in each group. Two Wilmsâ tumour antigen 1 (WT1) molecular responses were observed in the vaccinated group and one was observed in the control group. At an immunological level, the vaccine performed as expected.Conclusions: The study met its primary decision-making target with one major molecular response in BCRâABL transcript levels. Overall, the data showed, in this clinical setting, the immunogenicity and safety of the vaccine.Limitations: The study did not complete recruitment and there were multiple hurdles that contributed to this failure. This is disappointing given the robust induction immune responses against WT1 T-cell responses in 7 out of 10 evaluable patients.Future work: Evaluation of the p.DOMâWT1 vaccines in AML remains attractive clinically, but it is unlikely to be feasible at this time. Combination of the DNA vaccine approach with strategies to expand T-cell responses with immunomodulatory antibodies is in development.Funding details: This project was funded by the Efficacy and Mechanism Evaluation (EME) programme, a Medical Research Council (MRC) and National Institute for Health Research (NIHR) partnership, and Bloodwise
A survey of player monitoring approaches and microsensor use in basketball
The purpose of this study was to examine player monitoring approaches used by basketball practitioners with a specific focus on the use of microsensors. An online survey was disseminated to basketball practitioners via international basketball-related organisations and social media channels. Multiple response, Likert-scale level of agreement, and open-ended questions captured data regarding if, and how player monitoring was performed, as well as barriers and facilitators to player monitoring, with an emphasis on the use of microsensors. Forty-four basketball practitioners completed the survey. Twenty-seven respondents (61%) implement player monitoring and thirteen (30%) use microsensors. Despite implementing player monitoring, over 85% of practitioners modify training based on their own observation. Respondents not currently monitoring players (39%) would commence monitoring if the tools or equipment were provided. 74% of respondents agree that microsensors are expensive. Only 56% of practitioners who use microsensors feel they have support for using the technology and analysing/interpreting the data. These findings suggest a low uptake of microsensors for player monitoring in basketball. Coaches and practitioners perceive player monitoring approaches to be cost-prohibitive and appear unsure of how player monitoring data should be used to optimise training outcomes for players.This research was supported under the Commonwealth Governmentâs Research Training Program. The lead author gratefully acknowledge the financial support provided by the Australian Government
Surface freshening in the Arctic Ocean's Eurasian Basin : an apparent consequence of recent change in the wind-driven circulation
Author Posting. © American Geophysical Union, 2011. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 116 (2011): C00D03, doi:10.1029/2011JC006975.Data collected by an autonomous ice-based observatory that drifted into the Eurasian Basin between April and November 2010 indicate that the upper ocean was appreciably fresher than in 2007 and 2008. Sea ice and snowmelt over the course of the 2010 drift amounted to an input of less than 0.5 m of liquid freshwater to the ocean (comparable to the freshening by melting estimated for those previous years), while the observed change in upper-ocean salinity over the melt period implies a freshwater gain of about 0.7 m. Results of a wind-driven ocean model corroborate the observations of freshening and suggest that unusually fresh surface waters observed in parts of the Eurasian Basin in 2010 may have been due to the spreading of anomalously fresh water previously residing in the Beaufort Gyre. This flux is likely associated with a 2009 shift in the large-scale atmospheric circulation to a significant reduction in strength of the anticyclonic Beaufort Gyre and the Transpolar Drift Stream.This work was
funded by the National Science Foundation Office of Polar Programs Arctic
Sciences Section under awards ARCâ0519899, ARCâ0856479, and ARCâ
0806306
Integrated risk mapping and landscape characterisation of lymphatic filariasis and loiasis in South West Nigeria
Nigeria has the heaviest burden of lymphatic filariasis (LF) in sub-Saharan Africa, which is caused by the parasite Wuchereria bancrofti and transmitted by Anopheles mosquitoes. LF is targeted for elimination and the national programme is scaling up mass drug administration (MDA) across the country to interrupt transmission. However, in some regions the co-endemicity of the filarial parasite Loa loa (loiasis) is an impediment due to the risk of severe adverse events (SAEs) associated with the drug ivermectin. To better understand factors influencing LF elimination in loiasis areas, this study conducted a cross-sectional survey on the prevalence and co-distribution of the two infections, and the potential demographic, landscape, human movement, and intervention-related risk factors at a micro-level in the South West zone of Nigeria. In total, 870 participants from 10 communities on the fringe of a meso-endemic loiasis area of Osun State were selected. LF prevalence was measured by clinical assessment and using the rapid immunochromatographic test (ICT) to detect W. bancrofti antigen. Overall LF prevalence was low with ICT positivity ranging from 0 to 4.7%, with only 1 hydrocoele case identified. Males had significantly higher ICT positivity than females (3.2% vs 0.8%). Participants who did not sleep under a bed net had higher ICT positivity (4.0%) than those who did (1.3%). ICT positivity was also higher in communities with less tree coverage/canopy height (2.5â2.8%) than more forested areas with greater tree coverage/canopy height (0.9â1.0%). In comparison, loiasis was determined using the rapid assessment procedure for loiasis (RAPLOA), and found in all 10 communities with prevalence ranging from 1.4% to 11.2%. No significant difference was found by participants' age or sex. However, communities with predominately shrub land (10.4%) or forested land cover (6.2%) had higher prevalence than those with mosaic vegetation/croplands (2.5%). Satellite imagery showed denser forested areas in higher loiasis prevalence communities, and where low or no ICT positivity was found. Only one individual was found to be co-infected. GPS tracking of loiasis positive cases and controls also highlighted denser forested areas within higher loiasis risk communities and the sparser land cover in lower-risk communities. Mapping LF-loiasis distributions against landscape characteristics helped to highlight the micro-heterogeneity, identify potential SAE hotspots, and determine the safest and most appropriate treatment strategy
Stillbirths: Where? When? Why? How to make the data count?
Despite increasing attention and investment for maternal, neonatal, and child health, stillbirths remain invisible-not counted in the Millennium Development Goals, nor tracked by the UN, nor in the Global Burden of Disease metrics. At least 2·65 million stillbirths (uncertainty range 2·08 million to 3·79 million) were estimated worldwide in 2008 (â„1000 g birthweight or â„28 weeks of gestation). 98% of stillbirths occur in low-income and middle-income countries, and numbers vary from 2·0 per 1000 total births in Finland to more than 40 per 1000 total births in Nigeria and Pakistan. Worldwide, 67% of stillbirths occur in rural families, 55% in rural sub-Saharan Africa and south Asia, where skilled birth attendance and caesarean sections are much lower than that for urban births. In total, an estimated 1·19 million (range 0·82 million to 1·97 million) intrapartum stillbirths occur yearly. Most intrapartum stillbirths are associated with obstetric emergencies, whereas antepartum stillbirths are associated with maternal infections and fetal growth restriction. National estimates of causes of stillbirths are scarce, and multiple (>35) classification systems impede international comparison. Immediate data improvements are feasible through household surveys and facility audit, and improvements in vital registration, including specific perinatal certificates and revised International Classification of Disease codes, are needed. A simple, programme-relevant stillbirth classification that can be used with verbal autopsy would provide a basis for comparable national estimates. A new focus on all deaths around the time of birth is crucial to inform programmatic investment
Community-based field implementation scenarios of a short message service reporting tool for lymphatic filariasis case estimates in Africa and Asia
BACKGROUND: Lymphatic filariasis (LF) is a neglected tropical disease (NTD) targeted for global elimination by 2020. Currently there is considerable international effort to scale-up morbidity management activities in endemic countries, however there remains a need for rapid, cost-effective methods and adaptable tools for obtaining estimates of people presenting with clinical manifestations of LF, namely lymphoedema and hydrocele. The mHealth tool 'MeasureSMS-Morbidity' allows health workers in endemic areas to use their own mobile phones to send clinical information in a simple format using short message service (SMS). The experience gained through programmatic use of the tool in five endemic countries across a diversity of settings in Africa and Asia is used here to present implementation scenarios that are suitable for adapting the tool for use in a range of different programmatic, endemic, demographic and health system settings. METHODS: A checklist of five key factors and sub-questions was used to determine and define specific community-based field implementation scenarios for using the MeasureSMS-Morbidity tool in a range of settings. These factors included: (I) tool feasibility (acceptability; community access and ownership); (II) LF endemicity (high; low prevalence); (III) population demography (urban; rural); (IV) health system structure (human resources; community access); and (V) integration with other diseases (co-endemicity). RESULTS: Based on experiences in Bangladesh, Ethiopia, Malawi, Nepal and Tanzania, four implementation scenarios were identified as suitable for using the MeasureSMS-Morbidity tool for searching and reporting LF clinical case data across a range of programmatic, endemic, demographic and health system settings. These include: (I) urban, high endemic setting with two-tier reporting; (II) rural, high endemic setting with one-tier reporting; (III) rural, high endemic setting with two-tier reporting; and (IV) low-endemic, urban and rural setting with one-tier reporting. CONCLUSIONS: A decision-making framework built from the key factors and questions, and the resulting four implementation scenarios is proposed as a means of using the MeasureSMS-Morbidity tool. This framework will help national LF programmes consider appropriate methods to implement a survey using this tool to improve estimates of the clinical burden of LF. Obtaining LF case estimates is a vital step towards the elimination of LF as a public health problem in endemic countries
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