For the detection of compounds having enolisable or phenolic β-diketone group, the method employing uranyl ion was found to be recommendable by the fact that it is more selective and sensitive than the known methods using titanium (III) or iron (III) ion which gives color reaction both with β-diketones and phenols. The reaction with uranyl ion proposed here is based on the formation of a colored chelate compound which is stable in an acetic acid medium.
The mode of elevating action of 4-dimethylaminoazobenzene (DAB) metabolizing enzyme activity in the liver of rats fed copper was studied. The increases of the enzyme activity and flavin content were found with that of copper content in the liver homo-genates and microsomes of rats fed copper. But addition in vitro of cupric ion and/or fravin adenine dinucleotide (FAD) in the reaction mixture involving microsomal prepara-tions did not cause a marked enhancement of the enzyme activity. This fact is thought to indicate the both increases of flavin and apoenzyme. The concurrent administration of copper and 3'-methyl-4-dimethylaminoazobenzene (3'-Me-DAB) showed additive effect in reduced nicotinamide adenine dinucleotide phosphate (NADPH) cytochrome c reductase activity and competitive effect in DAB azo reductase activity.
The dithizone method for determination of mercury in JIS K 0 102 (Testing Methods for Industrial Waste Water) was improved for the determination of total mercury in sludge. In the improved method, the sludge was decomposed in HNO3-KMnO4 medium using an apparatus described in the Standard Methods for Hygienic Chemists in place of the JIS decomposition bottle. Recovery of mercury from the sludge added with C2H5HgCl was 91.2%, and was almost quantitative. Application of this method for the determinations of total mercury in sludges obtained in sea at Ichihara Industrial Area in Chiba Prefecture was proved to be fairly satisfactory. The average recovery of mercury from these sludges was 99.6%, and the deviation was within 10%.
The dissociation products of p-nitrophenyl glucuronide with L-ascorbic acid and cupric ion, or with hydrogen peroxide and cupric ion were identified as p-nitrophenol, 4-nitrocatechol, glucuronic acid, and glucaric acid which is a strong inhibitor of β-glucuronidase. It was assumed that p-nitrophenyl glucuronide was hydrolyzed to p-nitrophenol and glucuronic acid. With L-ascorbic acid and cupric ion or with hydrogen peroxide and cupric ion, glucuronic acid was oxidized easily to glucaric acid, and p-nitrophenol to 4-nitrocatechol. Therefore, 4-nitrocatechol and glucaric acid might be produced respectively from p-nitrophenol and glucuronic acid, which were the primary dissociation products of the glucuronide. However, it is also possible that p-nitrophenyl glucuronide is dissociated oxidatively to 4-nitrocatechol and glucaric acid.
Dimethylnitrosamine was administered to mice by ip injection once a week for 3 weeks and a high incidence of lung tumor was found 6 approximately 8 months after the final injection. In experiment I, the incidence of mice with lung tumors was 74% and the average number of nodules per mouse was 15.6 within 6.0 months after the final injection of dimethylnitrosamine. In mice given aluminium pretreatment, these values decreased to 65% and 6.7 (P less than 0.05), respectively. In experiment II, the incidence of mice with lung tumors was 100% and the average number of nodules per mouse was 8.7 within 7.5 months after the final injection of dimethylnitrosamine. In mice given aluminium pretreatment, these values decreased to 79% and 4.6 (P less than 0.05), respectively.
Abstract The probiotic Lactobacillus brevis KB290 is a natural producer of cell‐bound exopolysaccharide (EPS), and the plasmid‐encoded glycosyltransferase genes are responsible for this EPS production. KB290 forms unique rugose colonies inside an agar medium; this characteristic is useful for detecting and enumerating KB290 in the gut or feces. However, the genetic elements associated with this morphology remain unclear. Here, we aimed to investigate the relation between the plasmid eps genes and rugose colony morphology in KB290. The plasmid‐cured mutants formed smooth colonies, and the rugose colony morphology was restored after complementation with the eps genes. The eps genes were successfully cloned and expressed in other L. brevis and L. plantarum strains. In these transformant strains, the presence of the EPS, consisting of glucose and N ‐acetylglucosamine, correlated with rugose colonies, indicating that EPS is responsible for rugose colony formation. To the best of our knowledge, this is the first report identifying the genetic factors influencing rugose colonies in Lactobacillus strains. This rugose colony formation may serve as a useful selective marker for KB290 in routine laboratory and research settings and can be used to detect the spontaneous loss of plasmids in this strain.
Background:Chronic -blocker therapy improves survival and left ventricular (LV) systolic function in patients with congestive heart failure. However, its efficacy in diastolic heart failure (DHF) with preserved normal LV systolic function remains uncertain.
