149 research outputs found

    M-health review: joining up healthcare in a wireless world

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    In recent years, there has been a huge increase in the use of information and communication technologies (ICT) to deliver health and social care. This trend is bound to continue as providers (whether public or private) strive to deliver better care to more people under conditions of severe budgetary constraint

    Disruption of the Unique ABCG-Family NBD:NBD Interface Impacts Both Drug Transport and ATP Hydrolysis

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    ABCG2 is one of a triumvirate of human multidrug ATP binding cassette (ABC) transporters that are implicated in defense of cells and tissues against cytotoxic chemicals, but which can confer chemotherapy resistance states in oncology. Understanding the mechanism of ABCG2 is thus imperative if we are to be able to counter its deleterious activity. The structure of ABCG2 and related family members (ABCG5/G8) demonstrated that there were two interfaces between the nucleotide binding domains. In addition to the canonical ATP “sandwich-dimer” interface, there was a second contact region between residues at the C-terminus of the NBD. We mutated this second interface by making mutations to a series of residues which are in close interaction with the opposite NBD. Mutated ABCG2 isoforms were expressed in HEK293T cells and analyzed for targeting to the membrane, drug transport and ATPase activity. Mutations to this second interface had a number of effects on ABCG2 including altered drug specificity, altered drug transport and, in two mutants, a loss of ATPase activity. The results demonstrate that this region is particularly sensitive to mutation and can impact upon both direct, local NBD events (i.e. ATP hydrolysis) but also on the allosteric communication to the transmembrane domains and drug transport

    Pre-hospital pain management by ambulance staff

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    BACKGROUND In the 2004 Healthcare Commission report the majority of patients (4 out of 5) said they had suffered pain from their presenting conditions while in the ambulance. Although 81% felt that the ambulance crew did everything they could to control pain, 1 in 5 wanted more pain relief: 14% said the crew did this to some extent and 5% that the crew did not do everything they could to control the pain. The management of pain in the pre-hospital environment has been shown to be an important determinant of subsequent pain in the emergency department. How ambulance services manage pain is therefore clinically important and a key indicator of quality of service. Management of pain can be differentiated into a number of essential components. Recording of pain both at the scene (either the patient's home or the scene of an emergency) and on arrival at hospital has been shown to be feasible using numerical, verbal 1 and visual analogue scales 2 . Recording pain scores is valuable, not only because it is a simple method of assessing pain, but because it has been shown to increase the likelihood of administration of analgesia and facilitates an estimation of the effectiveness of treatment. 3 In one study, a reduction in pain score of at least 20mm out of 100mm on a visual analogue scale corresponded to a clinically meaningful reduction in the level of pain reported by patients experiencing acute pain 4 . The type, dose, route 5;6 and timeliness 7 of analgesia are important determinants of the effectiveness of pain relief. Strong analgesics including opiates have been available for use by paramedics for the management of pain since the early 1990s.. The feasibility of pain assessment in the prehospital setting. Prehosp.Emerg.Care 2004;8:155-61. 2 Lord BA,.Parsell B. Measurement of pain in the prehospital setting using a visual analogue scale. Prehospital.Disaster.Med. 2003;18:353-8. 3 Silka PA, Roth MM, Moreno G, Merrill L, Geiderman JM, Pain scores improve analgesic administration patterns for trauma patients in the emergency department. Acad.Emerg.Med. 2004;11:264-70. 4 Kelly AM. Setting the benchmark for research in the management of acute pain in emergency departments. Emerg.Med.(Fremantle.) 2001;13:57-60. 5 Woollard M, Jones T, Pitt K, Vetter N. Hitting them where it hurts? Low dose nalbuphine therapy. Emerg.Med.J. et al. Less IS less: a randomised controlled trial comparing cautious and rapid nalbuphine dosing regimens. Emerg.Med.J. 2004;21:362-4. 7 Karlson BW, Sjolin M, Herlitz J. Clinical factors associated with pain in acute myocardial infarction. Cardiology 1993;83:107-17. RESEARCH AIMS The aim of the study is to examine whether factors such age, sex, condition of the patient, and distance from hospital etc affect decisions to assess pain and/or administer analgesia

    Application of fluorescence correlation spectroscopy to study substrate binding in styrene maleic acid lipid copolymer encapsulated ABCG2

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    © 2020 The Authors ABCG2 is one of a trio of human ATP binding cassette transporters that have the ability to bind and transport a diverse array of chemical substrates out of cells. This so-called “multidrug” transport has numerous physiological consequences including effects on how drugs are absorbed into and eliminated from the body. Understanding how ABCG2 is able to interact with multiple drug substrates remains an important goal in transporter biology. Most drugs are believed to interact with ABCG2 through the hydrophobic lipid bilayer and experimental systems for ABCG2 study need to incorporate this. We have exploited styrene maleic acid to solubilise ABCG2 from HEK293T cells overexpressing the transporter, and confirmed by dynamic light scattering and fluorescence correlation spectroscopy (FCS) that this results in the extraction of SMA lipid copolymer (SMALP) particles that are uniform in size and contain a dimer of ABCG2, which is the predominant physiological state. FCS was further employed to measure the diffusion of a fluorescent ABCG2 substrate (BODIPY-prazosin) in the presence and absence of SMALP particles of purified ABCG2. Autocorrelation analysis of FCS traces enabled the mathematical separation of free BODIPY-prazosin from drug bound to ABCG2 and allowed us to show that combining SMALP extraction with FCS can be used to study specific drug: transporter interactions

    The adaptor protein melanophilin regulates dynamic myosin-Va:cargo interaction and dendrite development in melanocytes

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    Regulation of organelle transport by the cytoskeleton is fundamental for eukaryotic survival. Cytoskeleton motors are typically modular proteins with conserved motor and diverse cargo binding domains. Motor:cargo interactions are often indirect and mediated by adaptor proteins e.g. Rab GTPases. Rab27a, via effector melanophilin (Mlph), recruits myosin-Va to melanosomes and thereby disperses them into melanocytes dendrites. To better understand how adaptors regulate motor:cargo interaction we used single melanosome fluorescence recovery after photo-bleaching (smFRAP) to characterise the association kinetics between myosin-Va, its adaptors and melanosomes. We found that myosin-Va and Mlph rapidly recovered after photo-bleaching, while Rab27a did not, indicating that myosin-Va and Mlph dynamically associate with melanosomes and Rab27a does not. This suggests that dynamic Rab27a:effector interaction rather than Rab27a melanosome:cytosol cycling regulates myosin-Va:melanosome association. Accordingly a Mlph-Rab27a fusion protein reduced myosin-Va smFRAP, indicating that it stabilised melanosomal myosin-Va. Finally, we tested the functional importance of dynamic myosin-Va:melanosome interaction. We found that while a myosin-Va-Rab27a fusion protein dispersed melanosomes in myosin-Va deficient cells, dendrites were significantly less elongated than in wild-type cells. Given that dendrites are the prime sites of melanosome transfer from melanocytes to keratinocytes we suggest that dynamic myosin-Va:melanosome interaction is important for pigmentation in vivo. Movie S1 Movie S1 MVa-tail expressed in wild-type (melan-a) cells (supports Figure 1). Movie S2 Movie S2 MVa-tail expressed in myosin-Va -/- (melan-d) cells (supports Figure S1A). Movie S3 Movie S3 MVa-FL expressed in myosin-Va -/- (melan-d) cells (supports Figure S1C). Movie S4 Movie S4 Rab27a expressed in wild-type (melan-a) cells (supports Figure 2A). Movie S5 Movie S5 Rab27a expressed in Rab27a -/- (melan-ash) cells (supports Figure 2B). Movie S6 Movie S6 Rab27a expressed in Mlph -/- (melan-ln) cells (supports Figure 2C). Movie S7 Movie S7 Rab27aSF1F4 expressed in wild-type (melan-a) cells (supports Figure 2D). Movie S8 Movie S8 Mlph expressed in wild-type (melan-a) cells (supports Figure 3A). Movie S9 Movie S9 Mlph expressed in Mlph -/- (melan-ln) cells (supports Figure 3B). Movie S10 Movie S10 Mlph expressed in myosin-Va -/- (melan-d) cells (supports Figure 3C). Movie S11 Movie S11 MVa-tail co-expressed with mCherry-Mlph expressed in Mlph -/- (melan-ln) cells (supports Figure 4B). Movie S12 Movie S12 MVa-tail co-expressed with mCherry-Mlph-Rab27aSF1F4 expressed in Mlph -/- (melan-ln) cells (supports Figure 4C). Movie S13 Movie S13 GFP-Mlph- Rab27aSF1F4 expressed in Mlph -/- (melan-ln) cells (supports Figure S4). Movie S14 Movie S14 Mlph R27BD expressed in wild-type (melan-a) cells (supports Figure S5). Movie S15 Movie S15 Myo-Rab expressed in myosin-Va -/- (melan-d) cells (supports Figures 5 and S7). Movie S16 Movie S16 Sytl2 (R27BD) expressed in wild-type (melan-a) cells (supports Figures S8).publishersversionpublishe

    Evaluation of cost-effective strategies for rabies post-exposure vaccination in low-income countries

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    <b>Background:</b> Prompt post-exposure prophylaxis (PEP) is essential in preventing the fatal onset of disease in persons exposed to rabies. Unfortunately, life-saving rabies vaccines and biologicals are often neither accessible nor affordable, particularly to the poorest sectors of society who are most at risk and upon whom the largest burden of rabies falls. Increasing accessibility, reducing costs and preventing delays in delivery of PEP should therefore be prioritized.<p></p> <b>Methodology/Principal Findings:</b> We analyzed different PEP vaccination regimens and evaluated their relative costs and benefits to bite victims and healthcare providers. We found PEP vaccination to be an extremely cost-effective intervention (from 200tolessthan200 to less than 60/death averted). Switching from intramuscular (IM) administration of PEP to equally efficacious intradermal (ID) regimens was shown to result in significant savings in the volume of vaccine required to treat the same number of patients, which could mitigate vaccine shortages, and would dramatically reduce the costs of implementing PEP. We present financing mechanisms that would make PEP more affordable and accessible, could help subsidize the cost for those most in need, and could even support new and existing rabies control and prevention programs.<p></p> <b>Conclusions/Significance:</b> We conclude that a universal switch to ID delivery would improve the affordability and accessibility of PEP for bite victims, leading to a likely reduction in human rabies deaths, as well as being economical for healthcare providers.<p></p&gt

    The Central Component of Gravitational Lens Q0957+561

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    In 1981, a faint radio source (G') was detected near the center of the lensing galaxy of the famous "twin quasar" Q0957+561. It is still unknown whether this central radio source is a third quasar image or an active nucleus of the lensing galaxy, or a combination of both. In an attempt to resolve this ambiguity, we observed Q0957+561 at radio wavelengths of 13cm, 18cm, and 21cm, using the Very Long Baseline Array in combination with the phased Very Large Array and the Green Bank Telescope. We measured the spectrum of G' for the first time and found it to be significantly different from the spectra of the two bright quasar images. This finding suggests that the central component is primarily or entirely emission from the foreground lens galaxy, but the spectrum is also consistent with the hypothesis of a central quasar image suffering free-free absorption. In addition, we confirm the previously-reported VLBI position of G' just north of the optical center of the lens galaxy. The position slightly favors the hypothesis that G' originates in the lens, but is not conclusive. We discuss the prospects for further clarification of this issue.Comment: 18 pages, accepted for publication in A

    A time-resolved Förster resonance energy transfer assay to investigate drug and inhibitor binding to ABCG2

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    The human ATP-binding cassette (ABC) transporter, ABCG2, is responsible for multidrug resistance in some tumours. Detailed knowledge of its activity is crucial for understanding drug transport and resistance in cancer, and has implications for wider pharmacokinetics. The binding of substrates and inhibitors is a key stage in the transport cycle of ABCG2. Here, we describe a novel binding assay using a high affinity fluorescent inhibitor based on Ko143 and time-resolved Förster resonance energy transfer (TR-FRET) to measure saturation binding to ABCG2. This binding is displaced by Ko143 and other known ABCG2 ligands, and is sensitive to the addition of AMP-PNP, a non-hydrolysable ATP analogue. This assay complements the arsenal of methods for determining drug:ABCG2 interactions and has the possibility of being adaptable for other multidrug pumps
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