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Conditions Relevant (condition + relevant)
Selected AbstractsAdverse neurodevelopmental outcome in preterm infants: risk factor profiles for different gestational agesACTA PAEDIATRICA, Issue 5 2009U Kiechl-Kohlendorfer Abstract Aim: Assessment of risk predictors for adverse neurodevelopmental outcome at 1 year of age in preterm infants with a gestational age <30 weeks (Group I) and 30,32 weeks (Group II). Methods: Between January 2003 and December 2006, we prospectively enrolled 310 live-born infants between 23 and 32 weeks of gestation. The association between candidate risk factors and delayed motor or mental development (Bayley Scales of infant development II; psychomotor or mental developmental index <85) was analysed by means of logistic regression analysis. Results: Two hundred and fifty infants were eligible for follow-up, and 205 (82.0%) completed the follow-up visit. Intracerebral haemorrhage, small for gestational age and late-onset sepsis were associated with an increased risk for delayed development in Group I (p < 0.05, each). Premature rupture of membranes was a risk condition relevant to Group II. Antenatal steroids were associated with a decreased risk of neurodevelopmental delay in both groups. Conclusion: This study identified distinct risk factors for adverse outcome in preterm infants of lower (<30 weeks) and higher (30,32 weeks) gestational age. In the lower gestational age group, neonatal risk predictors are most important. Antenatal steroids appear to decrease the risk for adverse outcome in both age groups. [source] Experimental measurements and kinetic modeling of CH4/O2 and CH4/C2H6/O2 conversion at high pressure,INTERNATIONAL JOURNAL OF CHEMICAL KINETICS, Issue 12 2008Christian Lund Rasmussen A detailed chemical kinetic model for homogeneous combustion of the light hydrocarbon fuels CH4 and C2H6 in the intermediate temperature range roughly 500,1100 K, and pressures up to 100 bar has been developed and validated experimentally. Rate constants have been obtained from critical evaluation of data for individual elementary reactions reported in the literature with particular emphasis on the conditions relevant to the present work. The experiments, involving CH4/O2 and CH4/C2H6/O2 mixtures diluted in N2, have been carried out in a high-pressure flow reactor at 600,900 K, 50,100 bar, and reaction stoichiometries ranging from very lean to fuel-rich conditions. Model predictions are generally satisfactory. The governing reaction mechanisms are outlined based on calculations with the kinetic model. Finally, the mechanism was extended with a number of reactions important at high temperature and tested against data from shock tubes, laminar flames, and flow reactors. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 778,807, 2008 [source] Interaction between phosphorus and biodegradable organic carbon on drinking water biofilm subject to chlorinationJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2010S.-K. Park Abstract Aims:, To examine whether phosphorus and biodegradable organic carbon interact to impact biofilm density and physiological function of biofilm-forming bacteria under conditions relevant to chlorinated drinking water distribution systems. Materials and Results:, The 2 × 2 factorial experiments with low and high levels of phosphorus and biodegradable organic carbon were performed on 4 -week-old drinking water biofilms in four separate pipe systems in the presence of chlorine. Experimental results revealed that biofilm heterotrophic plate count levels increased with the increase in biodegradable organic carbon concentration, showed no response to increases in levels of phosphorus and was not affected by interaction between phosphorus and biodegradable organic carbon. However, a significant positive interaction between phosphorus and biodegradable organic carbon was found to exist on biofilm mass and physiological function and/or metabolic potentials of biofilm communities; the effects of biodegradable organic carbon on biofilm mass and physiological function of biofilm-forming bacteria were accelerated in going from low to high level of phosphorus. Conclusions:, Biodegradable organic carbon was found to be the primary nutrient in regulating biofilm formation in drinking water regardless of the presence of chlorine. It can be therefore concluded that the removal of an easily biodegradable organic carbon is necessary to minimize the biofilm growth potential induced by the intrusion of phosphorus. Significance and Impact of the Study:, Phosphorus introduced to drinking water may interact with biodegradable organic carbon, thus leading to measurable impact on the biofilm formation. [source] Miglustat (Zavesca®) in type 1 Gaucher disease: 5-year results of a post-authorisation safety surveillance programmePHARMACOEPIDEMIOLOGY AND DRUG SAFETY, Issue 9 2009Carla E. M. Hollak MD Abstract Purpose Miglustat (Zavesca®) is an orally-available substrate reduction therapy (SRT) for treatment of mild-to-moderate type 1 Gaucher disease (GD1) in adult patients unsuitable for enzyme replacement therapy (ERT). Miglustat has not been evaluated in children with GD1, and is not used during pregnancy and breast-feeding. A non-interventional, prospective, web-based safety surveillance programme was initiated at the time of the European launch of miglustat in 2003, and is ongoing. We report the first 5 years of collected data, focusing on neurological manifestations. Methods Data were collected on 122 GD1 patients between March 2003 and April 2008, representing 244 patient-years cumulative miglustat post-authorisation experience. The electronically-captured data collected from participating physicians includes patient demographics, prior and current therapies, baseline disease manifestations and concurrent conditions, disease severity, duration of miglustat exposure, and safety-relevant information. Results Mean (SD) age at baseline was 46.1 (16.5) years. At baseline, bone disease and neurological manifestations were reported in 55.6 and 28.6% of patients, respectively; the latter included peripheral neuropathy (7.2%) and a wide variety of neurological symptoms and signs. In addition, 23.2% had other health conditions relevant to neurological status. During the reporting period, new neurological manifestations were reported in 23 (18.9%) patients, principally tremor. Thirty-five (28.7%) patients discontinued treatment, predominantly for gastrointestinal (GI) disturbances (11.5%), two-thirds of which occurred during the first 6 months. Conclusion The safety profile of miglustat in GD1 patients included in the safety surveillance programme is overall consistent with that reported in the registration and other clinical trials, and no new safety finding was identified. Copyright © 2009 John Wiley & Sons, Ltd. [source] Use of labelled nitrogen to measure gross and net rates of mineralization and microbial activity in permanent pastures following fertilizer applications at different time intervals,RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 23 2002David J. Hatch Measurements of some of the main internal N-cycling processes in soil were obtained by labelling the inorganic N pool with the stable isotope of nitrogen (15N). The 15N mean pool dilution technique, combined with other field measurements, enabled gross and net N-mineralization rates to be resolved in grassland soils, which had previously either received fertilizer N (F), or had remained unfertilized (U) for many years. The two soils were subdivided into plots that received N at different time intervals (over 3 weeks), prior to 15N measurements being made. By this novel approach, possible ,priming' effects over time were investigated to try to overcome some of the temporal problems of isotopic labelling of soil N (native plus fertilizer) and to identify possible changes in a range of primary N-transformation processes. The results suggested that an overall stimulation of microbially mediated processes occurred with all N treatments, but there were inconsistencies associated with the release of N, both in the timing and the degree to which different processes responded to the application of fertilizer N. The rates of these processes were, however, within the range of previously reported data and the 15N measurements were not adversely affected by the differences in N pools created by the treatments. Thus, the mean pool dilution technique was shown to be applicable to agricultural soils, under conditions relevant to grass swards receiving fertilizer. For example, between the,U and F treatments, the size of inorganic N pools increased by five-fold and gross rates of mineralization reached 3.5 and 4.8,µg N g,1 (dry soil) d,1, respectively, but did not vary greatly with the timing of N applications. A correlation (r2,=,0.57) was found between soil respiration (which is relatively simple to measure) and net mineralization (which is more time consuming), suggesting that the former might be used as an indicator of the latter. Although this relationship was stronger in previously unfertilized soils, the similarities found with fertilized soils suggest that this approach could be used to obtain information of wider agronomic value and would, therefore, warrant further work under a range of soil conditions. Copyright © 2002 John Wiley & Sons, Ltd. [source] No influence of magnetic fields on cell cycle progression using conditions relevant for patients during MRIBIOELECTROMAGNETICS, Issue 4 2003Ilka B. Schiffer Abstract The purpose of this study was to examine whether exposure to magnetic fields (MFs) relevant for magnetic resonance imaging (MRI) in clinical routine influences cell cycle progression in two tumor cell lines in vitro. HL60 and EA2 cells were exposed to four types of MFs: (i) static MF of 1.5 and 7.05 T, (ii) extremely low frequency magnetic gradient fields (ELFMGFs) with ±,10 mT/m and 100 Hz, as well as ±,100 mT/m and 100 Hz, (iii) pulsed high frequency MF in the radiofrequency (RF) range (63.6 MHz, 5.8 ,T), and (iv) a combination of (i,iii). Exposure periods ranged from 1 to 24 h. Cell cycle distribution (G0/G1, S, and G2/M phases) was analyzed by flow cytometry. Cell cycle analysis did not reveal differences between the exposed and the control cells. As expected, positive controls with irradiated (8 Gy) HL60 and EA2 cells showed a strong G2/M arrest. Using conditions that are relevant for patients during MRI, no influence of MFs on cell cycle progression was observed in these cell lines. Care was taken to control secondary parameters of influence, such as vibration by the MR scanner or temperature to avoid false positive results. Bioelectromagnetics 24:241-250, 2003. © 2003 Wiley-Liss, Inc. [source] Ligand-Gated Synthetic Ion ChannelsCHEMISTRY - A EUROPEAN JOURNAL, Issue 22 2005Pinaki Talukdar Abstract Supramolecular ,-stack architecture is fundamental in DNA chemistry but absent in biological and synthetic ion channels and pores. Here, a novel rigid-rod ,-stack architecture is introduced to create synthetic ion channels with characteristics that are at the forefront of rational design, that is, ligand gating by a conformational change of the functional supramolecule. Namely, the intercalation of electron-rich aromatics is designed to untwist inactive electron-poor helical ,-stacks without internal space into open barrel-stave ion channels. Conductance experiments in planar lipid bilayers corroborate results from spherical bilayers and molecular modeling: Highly cooperative and highly selective ligand gating produces small, long-lived, weakly anion selective, ohmic ion channels. Structural studies conducted under conditions relevant for function provide experimental support for helix,barrel transition as origin of ligand gating. Control experiments demonstrate that minor structural changes leading to internal decrowding suffice to cleanly annihilate chiral self-organization and function. [source] Medicinal Organometallic Chemistry: Designing Metal Arene Complexes as Anticancer AgentsCHEMISTRY - AN ASIAN JOURNAL, Issue 11 2008Abstract The field of medicinal inorganic chemistry is rapidly advancing. In particular organometallic complexes have much potential as therapeutic and diagnostic agents. The carbon-bound and other ligands allow the thermodynamic and kinetic reactivity of the metal ion to be controlled and also provide a scaffold for functionalization. The establishment of structure,activity relationships and elucidation of the speciation of complexes under conditions relevant to drug testing and formulation are crucial for the further development of promising medicinal applications of organometallic complexes. Specific examples involving the design of ruthenium and osmium arene complexes as anticancer agents are discussed. [source] Surface Composition of Materials Used as Catalysts for Methanol Steam Reforming: A Theoretical Study,CHEMPHYSCHEM, Issue 8 2006Kok Hwa Lim Dr. Abstract PdZn (1:1) alloy is assumed to be the active component of a promising catalyst for methanol steam reforming. Using density functional calculations on periodic supercell slab models, followed by atomistic thermodynamics modeling, we study the chemical composition of the surfaces PdZn(111) and, as a reference, Cu(111) in contact with water and hydrogen at conditions relevant to methanol steam reforming. For the two surfaces, we determine similar maximum adsorption energies for the dissociative adsorption of H2, O2, and the molecular adsorption of H2O. These reactions are calculated to be exothermic by about ,40, ,320, and ,20 kJ,mol,1, respectively. Using a thermodynamic analysis based on theoretically predicted adsorption energies and vibrational frequencies, we determine the most favorable surface compositions for given pressure windows. However, surface energy plots alone cannot provide quantitative information on individual coverages in a system of coupled adsorption reactions. To overcome this limitation, we employ a kinetic model, from which equilibrium surface coverages of H, O, OH, and H2O are derived. We also discuss the sensitivity of our results and the ensuing conclusions with regard to the model surfaces employed and the inaccuracies of our computational method. Our kinetic model predicts surfaces of both materials, PdZn and Cu, to be essentially adsorbate-free already from very low values of the partial pressure of H2. The model surfaces PdZn(111) and Cu(111) are predicted to be free of water-related adsorbates for a partial H2 pressure greater than 10,8 and 10,5 atm, respectively. [source] | ||||||||||||||||