186 research outputs found

    Dryland Clovers: A Phytochemical Resource

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    Recent developments in the utilisation of phytoestrogens of red clover (Wuttke et al., 2002) have encouraged us to investigate a wider range of Trifolium species for metabolites which could provide new product opportunities. The phytochemistry of the agronomically-important Trifolium species white (Trifolium repens) and red (T. pratense) clovers has been investigated in some detail (Foo et al., 2000; Sivakumaran et al., 2004). However numerous other clover species have been neglected in agriculture due to agronomic issues or the fact they are annuals and require more intensive management. While some of these clover species have been studied for their genetic diversity (Marshall et al., 2002), investigations of the chemical composition of these specific species has not been reported

    Effect of Three Legumes Containing Different Condensed Tannin Concentrations on the in Vitro Formation of the Pastoral Flavour Compound; Skatole

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    Feeding legumes, such as white clover (Trifolium repens), results in higher intakes and increased animal production compared to grasses (Ulyatt, 1981). Skatole is produced in the rumen from plant protein fermentation and is associated with undesirable pastoral flavours in meat (Young et al. 2002). Feeding white clover causes a greater skatole concentration in the rumen compared to perennial ryegrass (Lolium perenne) or Lotus corniculatus, as the protein in white clover is highly soluble and rapidly degraded (Schreurs et al., 2004). The condensed tannins (CT) in Lotus species slow protein degradation in the rumen (Aerts et al., 1999). The aim of this study was to determine the effect of legumes with different concentrations of CT on skatole formation

    Diffusion of hydrogen in crystalline silicon

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    The coefficient of diffusion of hydrogen in crystalline silicon is calculated using tight-binding molecular dynamics. Our results are in good quantitative agreement with an earlier study by Panzarini and Colombo [Phys. Rev. Lett. 73, 1636 (1994)]. However, while our calculations indicate that long jumps dominate over single hops at high temperatures, no abrupt change in the diffusion coefficient can be observed with decreasing temperature. The (classical) Arrhenius diffusion parameters, as a consequence, should extrapolate to low temperatures.Comment: 4 pages, including 5 postscript figures; submitted to Phys. Rev. B Brief Repor

    Tailored second line therapy in asthmatic children with the arginine-16 genotype

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    The arginine-16 beta-2 receptor genotype confers increased susceptibility to exacerbations in asthmatic children taking regular long acting beta-2 agonists. We therefore evaluated using montelukast as an alternative to salmeterol as tailored second line asthma controller therapy in children expressing this susceptible genotype. 62 persistent asthmatic children with the homozygous arginine-16 genotype were randomized to receive salmeterol 50ug bid or montelukast 5/10mg od as add on to inhaled fluticasone for 1 year. School absences (the primary outcome) were reduced with montelukast arm compared to salmeterol: difference in score = 0.40 (95%CI 0.07-0.87) p=0.005. Albuterol use was also reduced with montelukast compared with salmeterol: difference in score = 0.47 (95%CI 0.16-0.79) p<0.0001. Greater improvements occurred in both symptom and quality of life scores with montelukast vs salmeterol, while there was no difference in FEV1. Montelukast may be suitable as tailored second line controller therapy instead of salmeterol in asthmatic children expressing the susceptible arginine-16 genotype - moving towards a personalised medicine approach to management

    Environmental risk factors for respiratory infection and wheeze in young children:A multicentre birth cohort study

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    introduction: Respiratory infections and wheeze have a considerable impact on the health of young children and consume significant healthcare resources. We aimed to evaluate the effect of environmental factors on respiratory infections and symptoms in early childhood.Methods: Environmental risk factors including: daycare attendance; breastfeeding; siblings; damp within the home; environmental tobacco smoke (ETS); child's bedroom flooring; animal exposure; road traffic density around child's home; and solid fuel pollution within home were assessed in children recruited to the GO-CHILD multicentre prospective birth cohort study. Follow-up information on respiratory infections (bronchiolitis, pneumonia, otitis media and cold or flu), wheeze and cough symptoms, healthcare utilisation and medication prescription was collected by postal questionnaires at 12 and 24 months. Log binomial and ordered logistic regression models were fitted to the data.Results: Follow-up was obtained on 1344 children. Daycare was associated with increased odds of pneumonia (odds ratio [OR] = 2.39, 95% confidence interval [CI]: 1.04-5.49), bronchiolitis (OR = 1.40, 1.02-1.90), otitis media (OR = 1.68, 1.32-2.14) and emergency department attendance for wheeze (RR = 1.81, 1.17-2.80). Breastfeeding beyond 6 months was associated with a reduced odds of bronchiolitis (OR = 0.55, 0.39-0.77) and otitis media (OR = 0.75, 0.59-0.99). Siblings at home was associated with an increased odds of bronchiolitis (OR = 1.65, 1.18-2.32) and risk of reliever inhaler prescription (RR = 1.37, 1.02-1.85). Visible damp was associated with an increased odds of wheeze (OR = 1.85, 1.11-3.19), and risk of reliever inhaler (RR = 1.73, 1.04-2.89) and inhaled corticosteroid prescription (RR = 2.61, 1.03-6.59). ETS exposure was associated with an increased odds of primary care attendance for cough or wheeze (OR = 1.52, 1.11-2.08). Dense traffic around the child's home was associated with an increased odds of bronchiolitis (OR = 1.32, 1.08-2.29).Conclusion: Environmental factors likely influence the wide variation in infection frequency and symptoms observed in early childhood. Larger population studies are necessary to further inform and guide public health policy to decrease the burden of respiratory infections and wheeze in young children.</p

    The switch between acute and persistent paramyxovirus infection caused by single amino acid substitutions in the RNA polymerase P subunit

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    Paramyxoviruses can establish persistent infections both in vitro and in vivo, some of which lead to chronic disease. However, little is known about the molecular events that contribute to the establishment of persistent infections by RNA viruses. Using parainfluenza virus type 5 (PIV5) as a model we show that phosphorylation of the P protein, which is a key component of the viral RNA polymerase complex, determines whether or not viral transcription and replication becomes repressed at late times after infection. If the virus becomes repressed, persistence is established, but if not, the infected cells die. We found that single amino acid changes at various positions within the P protein switched the infection phenotype from lytic to persistent. Lytic variants replicated to higher titres in mice than persistent variants and caused greater infiltration of immune cells into infected lungs but were cleared more rapidly. We propose that during the acute phases of viral infection in vivo, lytic variants of PIV5 will be selected but, as the adaptive immune response develops, variants in which viral replication can be repressed will be selected, leading to the establishment of prolonged, persistent infections. We suggest that similar selection processes may operate for other RNA viruses

    Filaggrin gene defects are associated with eczema, wheeze, and nasal disease during infancy:Prospective study

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    This prospective cohort study describes associations between the presence of filaggrin gene mutations and eczema, rhinitis and wheeze from as early as age six months, raising new questions regarding underlying mechanisms and timing of interventions

    An FCER2 polymorphism is associated with increased oral leukotriene receptor antagonists and allergic rhinitis prescribing

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    The Fc Fragment of IgE Receptor II (FCER2) is expressed in several cells, such as macrophages, eosinophils, B cells and platelets. Studies have suggested that FCER2 is involved in the regulation of IgE responses, growth and differentiation of T and B cells, cellular adherence and antigen presentation. The activation of the receptor results in down-regulation of IgE-mediated immune responses. Two studies found that individuals with asthma on inhaled corticosteroids (ICS) with the CC genotype of the rs28364072 polymorphism had a two-fold increased odds of asthma exacerbations and uncontrolled asthma than individuals with at least one copy of the T allele (CT/TT)
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