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em QUB Research Portal - Research Directory and Institutional Repository for Queen's University Belfast


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Earlier studies in adults have indicated that increased oxidative stress may occur in the blood and airways of asthmatic subjects. Therefore the aim of this study was to compare the concentrations of antioxidants and protein carbonyls in bronchoalveolar lavage fluid of clinically stable atopic asthmatic children (AA, n = 78) with our recently published reference intervals for nonasthmatic children (C, n = 124). Additionally, lipid peroxidation products (malondialdehyde) in bronchoalveolar lavage fluid and several antioxidants in plasma were determined. Bronchoalveolar lavage concentrations (median and interquartile range) of ascorbate [AA: 0.433 (0.294-0.678) versus C: 0.418 (0.253-0.646) micromol/L], urate [AA: 0.585 (0.412-0.996) versus C: 0.511 (0.372-0.687) micromol/L], alpha-tocopherol [AA: 0.025 (0.014-0.031) versus C: 0.017 (0.017-0.260) micromol/L], and oxidized proteins as reflected by protein carbonyls [AA: 1.222 (0.970-1.635) versus C: 1.243 (0.813-1.685) nmol/mg protein] were similar in both groups (p > 0.05 in all cases). The concentration of protein carbonyls correlated significantly with the number of eosinophils, mast cells, and macrophages in AA children only. Concentrations of oxidized proteins and lipid peroxidation products (malondialdehyde) correlated significantly in AA children (r = 0.614, n = 11, p = 0.044). Serum concentrations of ascorbate, urate, retinol, alpha-tocopherol, beta-carotene, and lycopene were similar in both groups whereas alpha-carotene was significantly reduced in asthmatics. Overall, increased bronchoalveolar lavage eosinophils indicate ongoing airway inflammation, which may increase oxidatively modified proteins as reflected by increased protein carbonyl concentrations.

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A method for simulation of acoustical bores, useful in the context of sound synthesis by physical modeling of woodwind instruments, is presented. As with previously developed methods, such as digital waveguide modeling (DWM) [Smith, Comput. Music J. 16, pp 74-91 (1992)] and the multi convolution algorithm (MCA) [Martinez et al., J. Acoust. Soc. Am. 84, pp 1620-1627 (1988)], the approach is based on a one-dimensional model of wave propagation in the bore. Both the DWM method and the MCA explicitly compute the transmission and reflection of wave variables that represent actual traveling pressure waves. The method presented in this report, the wave digital modeling (WDM) method, avoids the typical limitations associated with these methods by using a more general definition of the wave variables. An efficient and spatially modular discrete-time model is constructed from the digital representations of elemental bore units such as cylindrical sections, conical sections, and toneholes. Frequency-dependent phenomena, such as boundary losses, are approximated with digital filters. The stability of a simulation of a complete acoustic bore is investigated empirically. Results of the simulation of a full clarinet show that a very good concordance with classic transmission-line theory is obtained.

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Tree-ring analysis of sub-fossil Pinus sylvestris L. and Quercus sp. and their associated sub-fossil insect assemblages from tree rot holes have been used to study a prehistoric forest buried in the basal peats at Tyrham Hall Quarry, Hatfield Moors SSSI, in the Humberhead Levels, eastern England. The site provided a rare opportunity to examine the date, composition, age structure and entomological biodiversity of a mid-Holocene Pinus-dominated forest. The combined approaches of dendrochronology and palaeoentomology have enabled a detailed picture of the forest to be reconstructed, within a precise time frame. The Pinus chronology has been precisely dated to 2921- 2445 BC against the English Quercus master curve and represents the first English Pinus chronology to be dendrochronologically dated. A suite of important xylophilous (wood-loving) beetles that are today very rare and four species that no longer live within the British Isles were also recovered, their disappearance associated with the decline in woodland habitats as well as possible climate change. The sub-fossil insects indicate that the characteristic species of the site's modern-day fauna were already in place 4000 years ago. These findings have important implications in terms of maintaining long-term invertebrate biodiversity of mire sites.

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OSI-7904L is a liposomal formulation of a potent thymidylate synthase (TS) inhibitor. This phase I study evaluated the safety, tolerability and pharmacokinetics (PK) of OSI-7904L administered in combination with oxaliplatin every 21 days in patients with advanced colorectal carcinoma. METHOD: A 3+3 study design was utilized at predefined dose levels. Polymorphisms in the TS enhancer region and XPD enzyme were investigated as potential predictors of efficacy and toxicity. RESULTS: Fourteen patients received 76 cycles of treatment. At the highest dose level (OSI-7904L 9 mg/m(2), oxaliplatin 130 mg/m(2)) investigated, one of nine patients experienced dose-limiting toxicity of grade 3 oral mucositis with cycle 1 and five further patients required dose reductions. The toxicity profile of stomatitis, diarrhea, nausea, fatigue, sensory neuropathy and skin rash was consistent with that expected for a TS inhibitor/oxaliplatin combination regimen. PK analysis showed high interpatient variability with no detectable interaction between OSI-7904L and oxaliplatin. Partial radiological responses were documented in two patients. CONCLUSIONS: The recommended regimen for further investigation is OSI-7904L 9 mg/m(2) and oxaliplatin 130 mg/m(2).