Central motor conduction in motor neuron disease

Central motor conduction time (CMCT) to abductor digiti minimi (ADM) and tibialis anterior (TA) was measured in 21 patients of motor neuron disease (MND). In the upper limb, the motor pathways were inexcitable in 13 and central motor conduction time (CMCT-ADM) was prolonged in 7 sides. In the lower limbs the motor pathways were inexcitable in 10 and CMCT-TA was prolonged in 14 sides. The CMCT abnormalities did not follow a constant pattern but were randomly distributed and were asymmetric in the upper limbs in 7 and lower limbs in 3 patients. Asymmetric and randomly focal abnormalities in central motor conduction in our patients are consistent with asymmetric and focal neuronopathy in MND.     

N-glycosylation of recombinant human interferon-gamma produced in different animal expression systems

Recombinant human interferon-gamma (IFN-gamma) was expressed in Chinese hamster ovary cells, baculovirus-infected Sf9 insect cells and the mammary gland of transgenic mice. The N-linked carbohydrate populations associated with both Asn25 and Asn97 glycosylation sites were characterized by matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS) in combination with exoglycosidase array sequencing. A site-specific analysis of dual (2N) and single (1N) site-occupancy variants of IFN-gamma derived from Chinese hamster ovary cells showed that N-glycans were predominantly of the complex bi- and triantennary type. Although Asn25-linked glycans were substituted with a core fucose residue, Asn97 N-glycans were predominantly non-fucosylated, and truncated complex and high-mannose oligosaccharide chains were also evident. Transgenic mouse derived IFN-gamma exhibited considerable site-specific variation in N-glycan structures. Asn25-linked carbohydrates were of the complex, core fucosylated type, Asn97-linked carbohydrates were mainly of the oligomannose type, with smaller proportions of hybrid and complex N-glycans. Carbohydrates associated with both glycosylation sites of IFN-gamma from Sf9 insect cells were mainly tri-mannosyl core structures, with fucosylation confined to the Asn25 site. These data demonstrate the profound influence of host cell type and protein structure on the N-glycosylation of recombinant proteins.     

Treatment of wastewater containing Pb and Fe using ion‐exchange techniques

Treatment of wastewater containing lead and iron was examined using two different ion‐exchange resins namely Duolite ES 467 (containing amino‐phosphonic functional groups) and a chelating ion‐exchange resin (containing hydroxamic acid functional groups). Initially different sorption parameters such as contact time, pH, concentrations of sorbent, sorbate and chloride ion were studied. The sorption kinetics was observed to be fast and equilibrium could be reached within 30 min. Lead sorption efficiency increased with increase in pH whereas the opposite trend was observed with iron. The presence of chloride ions greatly reduced the Pb sorption efficiency in the case of Duolite ES 467. Column studies were carried out to recover Pb and Fe individually using Duolite ES 467 resin. The maximum uptake of Pb at pH 2 and 3 was observed to be 11.63 and 33.96 g dm^?3 of resin respectively. Similarly, for Fe at pH 2 and 3 the uptake was observed to be 10.07 and 6.96 g dm^?3 of resin respectively. In the presence of chloride ions, column studies were carried out using Duolite ES 467 for iron and chelating ion‐exchange resin containing hydroxamic acid functional groups for lead sorption. Hydroxamic acid resin's loading capacity remains constant for at least up to 20 cycles. Copyright © 2005 Society of Chemical Industry