33 research outputs found
1,2-Bis(diphenylphosphino)-1,2-diethylhydrazine
The title compound, C28H30N2P2, adopts a well documented and studied gauche conformation around the hydrazine bond. Bond lengths and angles are in the typical ranges expected for P—N and P—C bonds. A normal hydrazine N—N bond length of 1.426 (3) Å is observed
Evidence for human norovirus infection of dogs in the United kingdom.
Human noroviruses (HuNoVs) are a major cause of viral gastroenteritis, with an estimated 3 million cases per year in the United Kingdom. HuNoVs have recently been isolated from pet dogs in Europe (M. Summa, C.-H. von Bonsdorff, and L. Maunula, J Clin Virol 53:244-247, 2012, http://dx.doi.org/10.1016/j.jcv.2011.12.014), raising concerns about potential zoonotic infections. With 31% of United Kingdom households owning a dog, this could prove to be an important transmission route. To examine this risk, canine tissues were studied for their ability to bind to HuNoV in vitro. In addition, canine stool samples were analyzed for the presence of viral nucleic acid, and canine serum samples were tested for the presence of anti-HuNoV antibodies. The results showed that seven different genotypes of HuNoV virus-like particles (VLPs) can bind to canine gastrointestinal tissue, suggesting that infection is at least theoretically possible. Although HuNoV RNA was not identified in stool samples from 248 dogs, serological evidence of previous exposure to HuNoV was obtained in 43/325 canine serum samples. Remarkably, canine seroprevalence for different HuNoV genotypes mirrored the seroprevalence in the human population. Though entry and replication within cells have not been demonstrated, the canine serological data indicate that dogs produce an immune response to HuNoV, implying productive infection. In conclusion, this study reveals zoonotic implications for HuNoV, and to elucidate the significance of this finding, further epidemiological and molecular investigations will be essential.This collaborative project was facilitated by the Society of Microbiology's President's Fund awarded to S.L.C. and by the Region des Pays de la Loire ARMINA project. This work was supported by a Ph.D. studentship from the Medical Research Council to S.L.C. and a Wellcome Trust Senior Fellowship to I.G. (WT097997MA). I.G. is a Wellcome Senior Fellow.This is the final published version of the article. It was originally published in the Journal of Clinical Microbiology (Caddy S, et al., Journal of Clinical Microbiology, 2015, 53, 1873-1883, doi:10.1128/JCM.02778-14). The final version is available at http://dx.doi.org/10.1128/JCM.02778-1
Study protocol for a randomized controlled trial comparing the efficacy of a specialist and a generic parenting programme for the treatment of preschool ADHD
BACKGROUND: The New Forest Parenting Programme (NFPP) is a home-delivered, evidence-based parenting programme to target symptoms of attention-deficit/hyperactivity disorder (ADHD) in preschool children. It has been adapted for use with 'hard-to-reach' or 'difficult-to-treat' children. This trial will compare the adapted-NFPP with a generic parenting group-based programme, Incredible Years (IY), which has been recommended for children with preschool-type ADHD symptoms.METHODS/DESIGN: This multicentre randomized controlled trial comprises three arms: adapted-NFPP, IY and treatment as usual (TAU). A sample of 329 parents of preschool-aged children with a research diagnosis of ADHD enriched for hard-to-reach and potentially treatment-resistant children will be allocated to the arms in the ratio 3:3:1. Participants in the adapted-NFPP and IY arms receive an induction visit followed by 12 weekly parenting sessions of 1½ hours (adapted-NFPP) or 2½ hours (IY) over 2.5 years. Adapted-NFPP will be delivered as a one-to-one home-based intervention; IY, as a group-based intervention. TAU participants are offered a parenting programme at the end of the study. The primary objective is to test whether the adapted-NFPP produces beneficial effects in terms of core ADHD symptoms. Secondary objectives include examination of the treatment impact on secondary outcomes, a study of cost-effectiveness and examination of the mediating role of treatment-induced changes in parenting behaviour and neuropsychological function. The primary outcome is change in ADHD symptoms, as measured by the parent-completed version of the SNAP-IV questionnaire, adjusted for pretreatment SNAP-IV score. Secondary outcome measures are: a validated index of behaviour during child's solo play; teacher-reported SNAP-IV (ADHD scale); teacher and parent SNAP-IV (ODD) Scale; Eyberg Child Behaviour Inventory - Oppositional Defiant Disorder scale; Revised Client Service Receipt Inventory - Health Economics Costs measure and EuroQol (EQ5D) health-related quality-of-life measure. Follow-up measures will be collected 6 months after treatment for participants allocated to adapted-NFPP and IY.DISCUSSION: This trial will provide evidence as to whether the adapted-NFPP is more effective and cost-effective than the recommended treatment and TAU. It will also provide information about mediating factors (improved parenting and neuropsychological function) and moderating factors (parent and child genetic factors) in any increased benefit.TRIAL REGISTRATION: Current Controlled Trials, ISRCTN39288126.</p
Regulatory T Cell Responses in Participants with Type 1 Diabetes after a Single Dose of Interleukin-2: A Non-Randomised, Open Label, Adaptive Dose-Finding Trial
BACKGROUND: Interleukin-2 (IL-2) has an essential role in the expansion and function of CD4+ regulatory T cells (Tregs). Tregs reduce tissue damage by limiting the immune response following infection and regulate autoreactive CD4+ effector T cells (Teffs) to prevent autoimmune diseases, such as type 1 diabetes (T1D). Genetic susceptibility to T1D causes alterations in the IL-2 pathway, a finding that supports Tregs as a cellular therapeutic target. Aldesleukin (Proleukin; recombinant human IL-2), which is administered at high doses to activate the immune system in cancer immunotherapy, is now being repositioned to treat inflammatory and autoimmune disorders at lower doses by targeting Tregs. METHODS AND FINDINGS: To define the aldesleukin dose response for Tregs and to find doses that increase Tregs physiologically for treatment of T1D, a statistical and systematic approach was taken by analysing the pharmacokinetics and pharmacodynamics of single doses of subcutaneous aldesleukin in the Adaptive Study of IL-2 Dose on Regulatory T Cells in Type 1 Diabetes (DILT1D), a single centre, non-randomised, open label, adaptive dose-finding trial with 40 adult participants with recently diagnosed T1D. The primary endpoint was the maximum percentage increase in Tregs (defined as CD3+CD4+CD25highCD127low) from the baseline frequency in each participant measured over the 7 d following treatment. There was an initial learning phase with five pairs of participants, each pair receiving one of five pre-assigned single doses from 0.04 × 106 to 1.5 × 106 IU/m2, in order to model the dose-response curve. Results from each participant were then incorporated into interim statistical modelling to target the two doses most likely to induce 10% and 20% increases in Treg frequencies. Primary analysis of the evaluable population (n = 39) found that the optimal doses of aldesleukin to induce 10% and 20% increases in Tregs were 0.101 × 106 IU/m2 (standard error [SE] = 0.078, 95% CI = -0.052, 0.254) and 0.497 × 106 IU/m2 (SE = 0.092, 95% CI = 0.316, 0.678), respectively. On analysis of secondary outcomes, using a highly sensitive IL-2 assay, the observed plasma concentrations of the drug at 90 min exceeded the hypothetical Treg-specific therapeutic window determined in vitro (0.015-0.24 IU/ml), even at the lowest doses (0.040 × 106 and 0.045 × 106 IU/m2) administered. A rapid decrease in Treg frequency in the circulation was observed at 90 min and at day 1, which was dose dependent (mean decrease 11.6%, SE = 2.3%, range 10.0%-48.2%, n = 37), rebounding at day 2 and increasing to frequencies above baseline over 7 d. Teffs, natural killer cells, and eosinophils also responded, with their frequencies rapidly and dose-dependently decreased in the blood, then returning to, or exceeding, pretreatment levels. Furthermore, there was a dose-dependent down modulation of one of the two signalling subunits of the IL-2 receptor, the β chain (CD122) (mean decrease = 58.0%, SE = 2.8%, range 9.8%-85.5%, n = 33), on Tregs and a reduction in their sensitivity to aldesleukin at 90 min and day 1 and 2 post-treatment. Due to blood volume requirements as well as ethical and practical considerations, the study was limited to adults and to analysis of peripheral blood only. CONCLUSIONS: The DILT1D trial results, most notably the early altered trafficking and desensitisation of Tregs induced by a single ultra-low dose of aldesleukin that resolves within 2-3 d, inform the design of the next trial to determine a repeat dosing regimen aimed at establishing a steady-state Treg frequency increase of 20%-50%, with the eventual goal of preventing T1D. TRIAL REGISTRATION: ISRCTN Registry ISRCTN27852285; ClinicalTrials.gov NCT01827735.This is the final version of the article. It first appeared from the Public Library of Science via http://dx.doi.org/10.1371/journal.pmed.100213
Samarium (II) iodine-mediated organic synthesis.
The aim of this project was the synthesis a range of carbocycles from carbohydrates using SmI2 as the key reagent. Carbocycles derived from functionalised cyclopentanes form important substructures in many natural compounds, many of which are biologically active. This therefore provides a route to many highly desirable biologically active analogues. The project was initiated with the selective preparation of a variety of substituted g- butyrolactone dimers. To the end of preparing the dimers, we foresaw that g-ketoesters would be ideal substrates: pinacolisation to the corresponding bis-Sm-alkoxide, followed by intramolecular cyclisation onto esters, was anticipated to afford the corresponding g- butyrolactone dimers. The requisite g-ketoester starting materials were readily available via the Stetter reaction of a variety of aryl aldehydes with some a,b-unsaturated esters. A range of g-butyrolactone dimers was prepared. In keeping with the pinacol type reaction, the second section of work investigated focussed on the pinacol coupling of a variety of 1,4-diketone analogues with SmI2. The primary substrate on which the study began was 2,3,5-tris-O-phenylmethyl-D-arabinose. A variety of functionalities was introduced at the anomeric position and pinacol coupling attempted. It was interesting to see the crucial role that the radical acceptor played in the success of the transformation. These functionalities include an O- methyl oxime, nitrile, butyl group and the thiophene. The O-methyl oxime proved to be a poor radical acceptor and after several attempts no success was attained. This therefore initiated a new study to find an improved radical acceptor. Both the butyl and thiophene groups successfully gave the desired cyclobutanol analogues. In addition to the pinacol reactions attempted with 2,3,5-tris-O-phenylmethyl-Darabinose analogues, pinacol coupling reactions were attempted with deoxy-analogues of D-ribose. Once again a variety of substitutions at the anomeric position were looked at. These include the phenyl, butyl and furan groups. Both the phenyl and butyl containing deoxy-analogues were successfully converted into cyclobutanol products. The first work described in this thesis focussed upon the pinacol cyclisation of chiral 1,4- diketone derivatives. The second section of work relied on a keto-olefin cyclisation reaction to afford the cyclobutane product. The first part of this aspect of the work looked at the construction of functionalised cyclobutanols from carbohydrate precursors via 4-exo-trig cyclisations. The work was initiated with a D-arabinose derived substrate, a sugar having trans stereochemistry at positions 2 and 3. The work was then extended to sugars having cis stereochemistry at position 2 and 3. 2,3:5,6-Di-O-isopropylidene-Dmannofuranose successfully gave three of the desired monomers. Due to the large protective groups at positions 5 and 6, dimer formation was not possible. Ultimately, success was obtained using D- lyxose as a starting substrate. After transforming the starting sugar to a substrate suitable to attempt a 4-exo-trig cyclisation on, four cyclobutane monomer products, along with a single dimer product, were obtained. The latter set of reactions was based on a defined reaction sequence revolving around a Wittig reaction and in situ oxidation sequence to set up the desired precursor for the SmI2-mediated cyclisation. It was desirous to probe the possibility of employing a different approach to setting up the direct precursor to the cyclisation reaction, one that did not rely on the Wittig-oxidation sequence. This new approach delineates a new methodology towards the formation of cyclobutanes, involving the SmI2-mediated cyclisation between an aldehyde and an activated alkene. In addition to the new route to cyclobutanes, a novel approach making use of an elimination reaction to form the desired enal is described. The synthesis of the desired analogue proved to be quite problematic but with very interesting conclusions being derived from varying various func tionalities on the precursor carbohydrate. The desired substrate containing an aldehyde and an a,b- unsaturated nitrile was finally synthesised and the well developed samarium diiodide methodology tested. The desired cyclobutanol analogue was obtained, along with a mixture of dimeric products.Prof. D.B.G. William
Synthesis of viridamine analogues for use in selective metal complexation studies
M.Sc.The aim of this project was the synthesis of viridamine analogues, to be used for selective metal complexation. This, therefore, required the synthesis of diketopiperazines, containing an imidazole-type side chain. The imidazole functionality was introduced into the synthesis via peptide acid coupling reaction between histidine and another amino acid. Before any coupling reactions were possible it was necessary to protect the carboxylic acid functionality of one of the two amino acids being used and the amine functionality of the other. This was to prevent mixed products forming. Owing to the continued difficulty at achieving selective N-protection of histidine, it was decided to make use of the corresponding methyl ester instead. After some initial attempts, it was found that the methyl ester of histidine, which was bought as the dihydrochloride salt, could be readily coupled to a variety of Boc protected amino acids. The Boc protected amino acids could be prepared under various conditions using di-tertbutyl dicarbonate. A range of conditions was investigated for the coupling of the two amino acids, i.e. the histidine methyl ester dihydrochloride and a Boc protected amino acid. Successful coupling was finally achieved using tetrahydrofuran as solvent, N-hydroxy benzotriazole as reaction promoter, N-methyl morpholine as a base and dicyclohexylcarbodiimide as the coupling agent. After varying the reaction conditions the optimised reaction conditions gave yields in the region of 76%. Once coupling had been achieved, it remained to cyclise the dipeptide. Cyclisation was preceded by the removal of the Boc protecting group either in situ or in a two step process. In the absence of the imidazole functionality, removal of the Boc group was readily achieved using trifluoroacetic acid. However, attempted deprotection of dipeptides containing the imidazole functionality led to decomposition of the dipeptide under identical conditions. It was therefore necessary to find an alternative form of deprotection. This was found in the form of formic acid, which proved to be successful in removing the Boc group and in effecting cyclisation to the analogous diketopiperazine. This particular form of in situ cyclisation proved to be very low yielding. This problem was circumvented by following the formic acid treatment by a period of reflux in a toluene I 2-butanol mixture. Cyclisation was effected with pure products being obtained in high yield, after column chromatography. Complexation reactions were initiated with the synthesised diketopiperazines but unfortunately no X-Ray diffraction studies could be carried out, due to the formation of amorphous solids instead of crystalline materials
1,2,4,5-Tetramethyl-3,6-diphenyl-1,2,4,5-tetraaza-3,6-diphosphinane
The title compound, C16H22N4P2, crystallizes about a centre of symmetry, leading to a chair conformation of the heterocyclic ring as is commonly found for this type of compound
Evaluation of cross-reactivity between antibodies against human and canine noroviruses, and between different CNV strains.
<p>Canine serum was pre-incubated with serial diutions of either pooled human norovirus VLPs from genogroups I and II (GI/GII) or pooled CNV VLPs. The ability to detect pooled CNV was analysed using ELISA (A). Canine serum was then pre-incubated with serial dilutions of each of the CNV strains VLPs separately. ELISAs were again used to analyse the ability to detect CNV strain 170 (B) and strain HK (C). No C33 seropositive sample of adequate titre was available for the blocking assay.</p