Patterns of intracranial signal intensity on magnetic resonance (MR) images were studied in nine patients undergoing long-term total parenteral nutrition therapy. The duration of therapy ranged from 5 months to 11 years (mean, 5.3 years). Symmetric increased signal intensity on T1-weighted MR images (hyperintense relative to white matter) was observed in the basal ganglia of all patients, without corresponding abnormality on T2-weighted images. Analysis of signal-intensity characteristics and distribution pattern suggests that the basis for these changes may be deposition of intravenously administered paramagnetic trace elements, especially manganese, and/or an astrogliotic reaction to such deposition.

The authors describe magnetic resonance (MR) imaging findings in a patient receiving long-term total parenteral nutrition (TPN) therapy in whom parenteral manganese administration was experimentally discontinued. MR imaging performed while the patient was receiving standard TPN solution demonstrated marked hyperintensity of the globi pallidi on T1-weighted images. Following cessation of parenteral manganese administration for 1 year, repeat MR imaging demonstrated regression of the abnormal signal intensity.

Drug stability and compatibility studies should be performed for all medications added to total nutrient admixtures (TNAs) before administration to patients. The stability of TNA components will vary depending on product selection and final concentrations. This variability prohibits generalizing published study results generically to TNAs containing untested products or combinations. Histamine receptor antagonists (H2RAs) are commonly administered by continuous infusion via nutrient solutions. When the delivery vehicle is a TNA, comparative stability and compatibility studies performed under similar test conditions are lacking. The stability of marketed parenteral H2RAs and of the investigational H2RA, nizatidine was analyzed in TNA solutions containing either Liposyn II or Intralipid at differing concentrations. All H2RAs remained at more than 90% of initial concentration at 24 hours. After 48 hours, only ranitidine concentrations fell to less than 90% in all study solutions. Each TNA containing an H2RA was within pH stability ranges for lipid products, and no change in particle size was detected during the 48-hour period. This is the first report determining H2RA compatibility and stability in TNA solutions with both 3% and 5% Intralipid and Liposyn II and using similar methodology for all standard H2RA concentrations. Results suggest that these drugs are stable for 24 hours in TNAs containing either lipid product. Beyond this time, administration of ranitidine may be unreliable because of poor stability under the conditions tested.

No abstract

The U.S. Department of Energy National Energy Technology Laboratory funded this research collaboration effort between NextEnergy and the University of Michigan, who successfully designed, built, and tested a reformer system, which produced highquality syngas for use in SOFC and other applications, and a novel reactor system, which allowed for facile illumination of photocatalysts. Carbon and raw biomass gasification, sulfur tolerance of non-Platinum Group Metals (PGM) based (Ni/CeZrO 2 ) reforming catalysts, photocatalysis reactions based on TiO 2 , and mild pyrolysis of biomass in ionic liquids (ILs) were investigated at low and medium temperatures (primarily 450 to 850 °C) in an attempt to retain some structural value of the starting biomass. Despite a wide range of processes and feedstock composition, a literature survey showed that, gasifier products had narrow variation in composition, a restriction used to develop operating schemes for syngas cleanup. Three distinct reaction conditions were investigated: equilibrium, autothermal reforming of hydrocarbons, and the addition of O 2 and steam to match the final (C/H/O) composition.Initial results showed rapid and significant deactivation of Ni/CeZrO 2 catalysts upon introduction of thiophene, but both stable and unstable performance in the presence of sulfur were obtained.The key linkage appeared to be the hydrodesulfurization activity of the Ni reforming catalysts. For feed stoichiometries where high H 2 production was thermodynamically favored, stable, albeit lower, H 2 and CO production were obtained; but lower thermodynamic H 2 concentrations resulted in continued catalyst deactivation and eventual poisoning. High H 2 levels resulted in thiophene converting to H 2 S and S surface desorption, leading to stable performance; low H 2 levels resulted in unconverted S and loss in H 2 and CO production, as well as loss in thiophene conversion. Bimetallic catalysts did not outperform Ni-only catalysts, and small Ni particles were found to have lower activities under S-free conditions, but did show less effect of S on performance, in this study.Imidazolium-based ILs, choline chloride compounds and low-melting eutectics of metal nitrates were evaluated, and it was found that, ILs have some capacity to dissolve cellulose and show thermal stability to temperatures where pyrolysis begins, have no vapor pressure, (simplifying product recoveries), and can dissolve ionic metal salts, allowing for the potential of catalytic reactions on breakdown intermediates. Clear evidence of photoactive commercial TiO 2 was obtained, but in-house synthesis of photoactive TiO 2 proved difficult, as did fixed-bed gasification, primarily due to the challenge of removing the condensable products from the reaction zone quickly enough to prevent additional reaction. Further investigation into additional non-PGM catalysts and ILs is recommended as a follow-up to this work.iv