A survey of drench resistance in sheep worms

Sheep worms which are resistant to chemical drenches have been detected with increasing freuency is Western Australia\u27s south-western farming areas between 977 and 1980. These worms have anthelmintic resistance and such genetis resistance puts essential internal parasite control practices at risk. This prompted veterinarians in the Esperance, Albany, Bunbury, Geraldton and Northam areas to survey farms to determine the prevalence of resistance to drenches and to define those sheep management practices which encourage its development. This article describes the survey which was conducted to assess the extent of drench resistance, what causes its build-up and how it can be controlled by using a combination of drenching programme changes and sheep management practices. It has been estimated that drench resistance alone could cost the State\u27s sheep industry $4 million to$6 million a year in lost production, and, as shis survey shows, there is potential for far greater costs if resistance continues to increase

Site-specific perturbations of alpha-synuclein fibril structure by the Parkinson's disease associated mutations A53T and E46K.

PMCID: PMC3591419This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Parkinson's disease (PD) is pathologically characterized by the presence of Lewy bodies (LBs) in dopaminergic neurons of the substantia nigra. These intracellular inclusions are largely composed of misfolded α-synuclein (AS), a neuronal protein that is abundant in the vertebrate brain. Point mutations in AS are associated with rare, early-onset forms of PD, although aggregation of the wild-type (WT) protein is observed in the more common sporadic forms of the disease. Here, we employed multidimensional solid-state NMR experiments to assess A53T and E46K mutant fibrils, in comparison to our recent description of WT AS fibrils. We made de novo chemical shift assignments for the mutants, and used these chemical shifts to empirically determine secondary structures. We observe significant perturbations in secondary structure throughout the fibril core for the E46K fibril, while the A53T fibril exhibits more localized perturbations near the mutation site. Overall, these results demonstrate that the secondary structure of A53T has some small differences from the WT and the secondary structure of E46K has significant differences, which may alter the overall structural arrangement of the fibrils

Solid-state NMR evidence for inequivalent GvpA subunits in gas vesicles

Gas vesicles are organelles that provide buoyancy to the aquatic microorganisms that harbor them. The gas vesicle shell consists almost exclusively of the hydrophobic 70-residue gas vesicle protein A, arranged in an ordered array. Solid-state NMR spectra of intact collapsed gas vesicles from the cyanobacterium Anabaena flos-aquae show duplication of certain gas vesicle protein A resonances, indicating that specific sites experience at least two different local environments. Interpretation of these results in terms of an asymmetric dimer repeat unit can reconcile otherwise conflicting features of the primary, secondary, tertiary, and quaternary structures of the gas vesicle protein. In particular, the asymmetric dimer can explain how the hydrogen bonds in the β-sheet portion of the molecule can be oriented optimally for strength while promoting stabilizing aromatic and electrostatic side-chain interactions among highly conserved residues and creating a large hydrophobic surface suitable for preventing water condensation inside the vesicle.National Institutes of Health (U.S.) (Grant EB002175)National Institutes of Health (U.S.) (Grant EB003151)National Institutes of Health (U.S.) (Grant EB002026

The Structure of the Chemokine Receptor CXCR1 in Phospholipid Bilayers and Interactions with IL-8

CXCR1 is one of two high-affinity receptors for the CXC chemokine interleukin-8 (IL-8), a major mediator of immune and inflammatory responses implicated in many disorders, including tumor growth(1-3). IL-8, released in response to inflammatory stimuli, binds to the extracellular side of CXCR1. The ligand-activated intracellular signaling pathways result in neutrophil migration to the site of inflammation(2). CXCR1 is a class-A, rhodopsin-like G-protein-coupled receptor (GPCR), the largest class of integral membrane proteins responsible for cellular signal transduction and targeted as drug receptors(4-7). Despite its importance, its molecular mechanism is poorly understood due to the limited structural information available. Recently, structure determination of GPCRs has advanced by tailoring the receptors with stabilizing mutations, insertion of the protein T4 lysozyme and truncations of their amino acid sequences(8), as well as addition of stabilizing antibodies and small molecules(9) that facilitate crystallization in cubic phase monoolein mixtures(10). The intracellular loops of GPCRs are critical for G-protein interactions(11) and activation of CXCR1 involves both N-terminal residues and extracellular loops(2,12,13). Our previous NMR studies indicate that IL-8 binding to the N-terminal residues is mediated by the membrane, underscoring the importance of the phospholipid bilayer for physiological activity(14). Here we report the three-dimensional structure of human CXCR1 determined by NMR spectroscopy. The receptor is in liquid crystalline phospholipid bilayers, without modification of its amino acid sequence and under physiological conditions. Features important for intracellular G-protein activation and signal transduction are revealed

Levetiracetam versus phenytoin for second-line treatment of paediatric convulsive status epilepticus (EcLiPSE): a multicentre, open-label, randomised trial

Background Phenytoin is the recommended second-line intravenous anticonvulsant for treatment of paediatric convulsive status epilepticus in the UK; however, some evidence suggests that levetiracetam could be an effective and safer alternative. This trial compared the efficacy and safety of phenytoin and levetiracetam for second-line management of paediatric convulsive status epilepticus.Methods This open-label, randomised clinical trial was undertaken at 30 UK emergency departments at secondary and tertiary care centres. Participants aged 6 months to under 18 years, with convulsive status epilepticus requiring second-line treatment, were randomly assigned (1:1) using a computer-generated randomisation schedule to receive levetiracetam (40 mg/kg over 5 min) or phenytoin (20 mg/kg over at least 20 min), stratified by centre. The primary outcome was time from randomisation to cessation of convulsive status epilepticus, analysed in the modified intention-to-treat population (excluding those who did not require second-line treatment after randomisation and those who did not provide consent). This trial is registered with ISRCTN, number ISRCTN22567894.Findings Between July 17, 2015, and April 7, 2018, 1432 patients were assessed for eligibility. After exclusion of ineligible patients, 404 patients were randomly assigned. After exclusion of those who did not require second-line treatment and those who did not consent, 286 randomised participants were treated and had available data: 152 allocated to levetiracetam, and 134 to phenytoin. Convulsive status epilepticus was terminated in 106 (70%) children in the levetiracetam group and in 86 (64%) in the phenytoin group. Median time from randomisation to cessation of convulsive status epilepticus was 35 min (IQR 20 to not assessable) in the levetiracetam group and 45 min (24 to not assessable) in the phenytoin group (hazard ratio 1·20, 95% CI 0·91–1·60; p=0·20). One participant who received levetiracetam followed by phenytoin died as a result of catastrophic cerebral oedema unrelated to either treatment. One participant who received phenytoin had serious adverse reactions related to study treatment (hypotension considered to be immediately life-threatening [a serious adverse reaction] and increased focal seizures and decreased consciousness considered to be medically significant [a suspected unexpected serious adverse reaction]). Interpretation Although levetiracetam was not significantly superior to phenytoin, the results, together with previously reported safety profiles and comparative ease of administration of levetiracetam, suggest it could be an appropriate alternative to phenytoin as the first-choice, second-line anticonvulsant in the treatment of paediatric convulsive status epilepticus

De Novo

The crystal structure of form 4 of the drug 4-[4-(2-adamantylcarbamoyl)-5-tert-butyl-pyrazol-1-yl]benzoic acid is determined using a protocol for NMR powder crystallography at natural isotopic abundance combining solid-state 1H NMR spectroscopy, crystal structure prediction, and density functional theory chemical shift calculations. This is the first example of NMR crystal structure determination for a molecular compound of previously unknown structure, and at 422 g/mol this is the largest compound to which this method has been applied so far