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Anti-Respiratory Syncytial Virus (RSV) Neutralizing Antibody Decreases Lung Inflammation, Airway Obstruction, and Airway Hyperresponsiveness in a Murine RSV Model. Asunción Mejías, 2004.Numerous studies have described a strong association between respiratory syncytial virus (RSV) infection in infancy and the development of recurrent wheezing and airway hyperresponsiveness . We evaluated the effect of an anti-RSV neutralizing monoclonal antibody (palivizumab) on different aspects of RSV disease by using a murine model . BALB/c mice were intranasally inoculated with RSV A2 . Palivizumab or an isotype-matched control antibody was administered once at 24 h before inoculation, 1 h after inoculation, or 48 h after inoculation . Regardless of the timing of administration, all mice treated with the neutralizing antibody showed significantly decreased RSV loads in bronchoalveolar lavage (BAL) and lung specimens compared with those of infected controls . Pulmonary histopathologic scores, airway obstruction measured by plethysmography, and airway hyperresponsiveness after methacholine challenge were significantly reduced in mice treated with the anti-RSV antibody 24 h before inoculation compared with those for untreated controls . Concentrations of interferon-gamma, interleukin-10, macrophage inflammatory protein 1  , regulated on activation normal T-cell expressed and secreted (RANTES), and eotaxin in BAL fluids were also significantly reduced in mice treated with palivizumab 24 h before inoculation . This study demonstrates that reduced RSV replication was associated with significant modulation of inflammatory and clinical markers of acute disease severity and significant improvement of the long-term pulmonary abnormalities . Studies to determine whether strategies aimed at preventing or reducing RSV replication could decrease the long-term morbidity associated with RSV infection in children should be considered .
Genetic Identification of a Putative Vinyl Chloride Reductase in Dehalococcoides sp . Strain BAV1. Rosa Krajmalnik-Brown, 2004. Periplasmic Nitrate Reductase (NapABC Enzyme) Supports Anaerobic Respiration by Escherichia coli K-12. Valley Stewart, 2002.Periplasmic nitrate reductase (NapABC enzyme) has been characterized from a variety of proteobacteria, especially Paracoccus pantotrophus . Whole-genome sequencing of Escherichia coli revealed the structural genes napFDAGHBC, which encode NapABC enzyme and associated electron transfer components . E . coli also expresses two membrane-bound proton-translocating nitrate reductases, encoded by the narGHJI and narZYWV operons . We measured reduced viologen-dependent nitrate reductase activity in a series of strains with combinations of nar and nap null alleles . The napF operon-encoded nitrate reductase activity was not sensitive to azide, as shown previously for the P . pantotrophus NapA enzyme . A strain carrying null alleles of narG and narZ grew exponentially on glycerol with nitrate as the respiratory oxidant (anaerobic respiration), whereas a strain also carrying a null allele of napA did not . By contrast, the presence of napA+ had no influence on the more rapid growth of narG+ strains . These results indicate that periplasmic nitrate reductase, like fumarate reductase, can function in anaerobic respiration but does not constitute a site for generating proton motive force . The time course of  (napF-lacZ) expression during growth in batch culture displayed a complex pattern in response to the dynamic nitrate/nitrite ratio . Our results are consistent with the observation that
(napF-lacZ) is expressed preferentially at relatively low nitrate concentrations in continuous cultures (H . Wang, C.-P . Tseng, and R . P . Gunsalus, J . Bacteriol . 181:5303-5308, 1999) . This finding and other considerations support the hypothesis that NapABC enzyme may function in E . coli when low nitrate concentrations limit the bioenergetic efficiency of nitrate respiration via NarGHI enzyme .
Effects of Furfural on the Respiratory Metabolism of Saccharomyces cerevisiae in Glucose-Limited Chemostats. Ilona Sárvári Horváth, 2003.Effects of furfural on the aerobic metabolism of the yeast Saccharomyces cerevisiae were studied by performing chemostat experiments, and the kinetics of furfural conversion was analyzed by performing dynamic experiments . Furfural, an important inhibitor present in lignocellulosic hydrolysates, was shown to have an inhibitory effect on yeast cells growing respiratively which was much greater than the inhibitory effect previously observed for anaerobically growing yeast cells . The residual furfural concentration in the bioreactor was close to zero at all steady states obtained, and it was found that furfural was exclusively converted to furoic acid during respiratory growth . A metabolic flux analysis showed that furfural affected fluxes involved in energy metabolism . There was a 50% increase in the specific respiratory activity at the highest steady-state furfural conversion rate . Higher furfural conversion rates, obtained during pulse additions of furfural, resulted in respirofermentative metabolism, a decrease in the biomass yield, and formation of furfuryl alcohol in addition to furoic acid . Under anaerobic conditions, reduction of furfural partially replaced glycerol formation as a way to regenerate NAD+ . At concentrations above the inlet concentration of furfural, which resulted in complete replacement of glycerol formation by furfuryl alcohol production, washout occurred . Similarly, when the maximum rate of oxidative conversion of furfural to furoic acid was exceeded aerobically, washout occurred . Thus, during both aerobic growth and anaerobic growth, the ability to tolerate furfural appears to be directly coupled to the ability to convert furfural to less inhibitory compounds .
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