RESUMO
The stability of 5 mg/mL ephedrine sulfate in 0.9% sodium chloride in 10-mL polypropylene syringes stored at ambient temperature and at 4 deg C for up to 60 days was investigated. Concentration levels of ephedrine sulfate were determined by means of a high-performance liquid chromatography stability-indicating assay at 0, 1, 4, 7, 14, 30, 45 and 60 days after preparation of the syringes. Benzyl alcohol, which was added as a preservative, did not interfere with the assay. The injections in polypropylene syringes were stable for up to 60 days at both ambient temperature and at 4 deg C. The pH of the ephedrine sulfate injections did not change appreciably in a particular direction during the 60-day study period. These data support the stability of ephedrine sulfate under the storage conditions investigated in this study.
RESUMO
The Bacillus subtilis genome encodes seven homologues of the small multidrug resistance (SMR) family of drug efflux pumps. Six of these homologues are paired in three distinct operons, and coexpression in Escherichia coli of one such operon, ykkCD, but not expression of either ykkC or ykkD alone, gives rise to a broad specificity, multidrug-resistant phenotype including resistance to cationic, anionic, and neutral drugs.
Assuntos
Antiporters/metabolismo , Bacillus subtilis/genética , Resistência Microbiana a Medicamentos/genética , Resistência a Múltiplos Medicamentos/genética , Proteínas de Membrana/metabolismo , Antiporters/genética , Bacillus subtilis/efeitos dos fármacos , Transporte Biológico Ativo/genética , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Proteínas de Escherichia coli , Genes Bacterianos , Proteínas de Membrana/genética , Óperon , Fenótipo , Homologia de Sequência de AminoácidosRESUMO
Temperate Myxococcus xanthus phage Mx8 integrates into the attB locus of the M. xanthus genome. The phage attachment site, attP, is required in cis for integration and lies within the int (integrase) coding sequence. Site-specific integration of Mx8 alters the 3' end of int to generate the modified intX gene, which encodes a less active form of integrase with a different C terminus. The phage-encoded (Int) form of integrase promotes attP x attB recombination more efficiently than attR x attB, attL x attB, or attB x attB recombination. The attP and attB sites share a common core. Sequences flanking both sides of the attP core within the int gene are necessary for attP function. This information shows that the directionality of the integration reaction depends on arm sequences flanking both sides of the attP core. Expression of the uoi gene immediately upstream of int inhibits integrative (attP x attB) recombination, supporting the idea that uoi encodes the Mx8 excisionase. Integrase catalyzes a reaction that alters the primary sequence of its gene; the change in the primary amino acid sequence of Mx8 integrase resulting from the reaction that it catalyzes is a novel mechanism by which the reversible, covalent modification of an enzyme is used to regulate its specific activity. The lower specific activity of the prophage-encoded IntX integrase acts to limit excisive site-specific recombination in lysogens carrying a single Mx8 prophage, which are less immune to superinfection than lysogens carrying multiple, tandem prophages. Thus, this mechanism serves to regulate Mx8 site-specific recombination and superinfection immunity coordinately and thereby to preserve the integrity of the lysogenic state.
