Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0085593 (chills)
 4,268 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Alternative methods of reducing oxygen during anaerobic enrichment in the Bacteriological Analytical Manual (BAM) Shigella culture method were evaluated and compared to the current and less practical GasPak method. The alternative anaerobic methods included the use of reducing agents in Shigella broth and reducing culture container headspace volume to minimize atmospheric effects on oxygen concentration in Shigella broth during enrichment. The reducing agents evaluated were sodium thioglycollate, L-cystine, L-cysteine, titanium(III) citrate, and dithiothreitol, each at concentrations of 0.1, 0.05, and 0.01%. The use of Oxyrase for Broth with the enrichment medium (Shigella broth) was evaluated at concentrations of 10, 20 and 30 microL/mL. Recoveries of chill- and freeze-stressed S. sonnei strains 357 and 20143 were determined with each anaerobic method, including the GasPak method, using inoculation levels ranging from 10(0)to 10(3) cells. For each anaerobic method, strain, inoculation level, and stress type, 5 replicate enrichments were evaluated by streaking to MacConkey agar for isolation. The numbers of cultures with each method from which S. sonnei was isolated were used to compare the alternative anaerobic methods to the GasPak method. The alternative anaerobic method with which chill- and freeze-stressed S. sonnei strains 357 and 20143 were isolated most consistently was the use of Oxyrase for Broth in Shigella broth at a concentration of 20 microL/mL. This method was compared to the GasPak anaerobic method in evaluations on the recovery of S. sonnei strains 357 and 20143 from artificially contaminated test portions of parsley, cilantro, green onions, strawberries, carrots, and celery. A third anaerobic method included the use of 0.5 cm mineral oil overlay on cultures containing Oxyrase for Broth at concentrations of 20 microL/mL. Recovery rates of strain 357 were significantly greater (p < 0.05) with the GasPak method than with Oxyrase for Broth, with and without the 0.5 cm mineral oil overlay, for test portions of parsley, cilantro, and celery. When Oxyrase for Broth was used with Shigella broth, strain 357 was isolated at higher rates from all produce types, except cilantro, when 0.5 cm mineral oil overlay was applied to enrichment cultures. The use of mineral oil overlay with Oxyrase for Broth also improved recovery of strain 20143 from test portions of all produce types except green onion and strawberries. These differences were significant (p < 0.05) with parsley, carrots, and cilantro (1 of 2 evaluations). No statistically significant differences (p > 0.05) between the GasPak and Oxyrase for Broth anaerobic methods occurred when mineral oil overlay was used with Oxyrase for Broth. The use of Oxyrase for Broth with a 0.5 cm mineral oil overlay is a practical alternative for anaerobic enrichment with the BAM method in the analysis of some produce types. Differences in recovery among the different produce types and methods occurred between S. sonnei strains 357 and 20143, emphasizing the need for additional S. sonnei strains in future evaluations.
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PMID:Alternative anaerobic enrichments to the bacteriological analytical manual culture method for isolation of Shigella sonnei from selected types of fresh produce. 1549 68

Brassinosteroids (BRs) regulate plant development and stress response. Although much has been learned about their roles in plant development, the mechanisms by which BRs regulate plant stress tolerance remain unclear. Chilling is a major stress that adversely affects plant growth. Here, we report that BR positively regulates chilling tolerance in tomato. BR partial deficiency aggravated chilling-induced oxidized protein accumulation, membrane lipid peroxidation, and decrease of maximum quantum efficiency of photosystem II (Fv/Fm). By contrast, overexpression of BR biosynthetic gene Dwarf or treatment with 24-epibrassinolide (EBR) attenuated chilling-induced oxidative damages and resulted in an increase of Fv/Fm. BR increased transcripts of RESPIRATORY BURST OXIDASE HOMOLOG1 (RBOH1) and GLUTAREDOXIN (GRX) genes, and BR-induced chilling tolerance was associated with an increase in the ratio of reduced/oxidized 2-cysteine peroxiredoxin (2-Cys Prx) and activation of antioxidant enzymes. However, RBOH1-RNAi plants failed to respond to EBR as regards to the induction of GRX genes, activation of antioxidant capacity, and attenuation of chilling-induced oxidative damages. Furthermore, silencing of GRXS12 and S14 compromised EBR-induced increases in the ratio of reduced/oxidized 2-Cys Prx and activities of antioxidant enzymes. Our study suggests that BR enhances chilling tolerance through a signalling cascade involving RBOH1, GRXs, and 2-Cys Prx in tomato.
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PMID:Brassinosteroid-mediated apoplastic H2 O2 -glutaredoxin 12/14 cascade regulates antioxidant capacity in response to chilling in tomato. 2877 92