Acute Toxicity of 14 Different Kinds of Metals Affecting Medaka Fry

We examined the acute toxicity of 14 different kinds of metals affecting medaka fry and from the results, arranged them according to the order of intensity level of acute toxicity. The most toxic metals to medaka fry were Ag, Hg, Cu, and Cd, the second most toxic were Zn, As, Cr, Ni, and Pb, and the third most toxic were Se, V, Fe, and Co. The metal least toxic to medaka fry was Mn

Effects of Ionic Radius of Redox-Inactive Bio-Related Metal Ions on the Radical-Scavenging Activity of Flavonoids Evaluated Using Photometric Titration

Mg(2+) enhanced the scavenging activity of (+)-catechin and quercetin against the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, while Al(3+) decreased their activity. Such effects of Mg(2+) and Al(3+) were not observed for kaempferol. Na(+) and Ca(2+) with large ionic radii showed little effect on the DPPH radical-scavenging activity of these three flavonoids

Isolation of poly[d-lactate (LA)-co-3-hydroxybutyrate)]-degrading bacteria from soil and characterization of D-LA homo-oligomer degradation by the isolated strains

P[d-lactate (LA)-co-3-hydroxybutyrate (3HB)] is an artificial polyhydroxyalkanoate (PHA) containing unusual D-LA units. In this study, the P(D-LA-co-3HB)-degrading bacterial group in the soil was analyzed and the bacterial degradation of the D-LA clustering structure in the copolymer were evaluated by using chemically synthetic D-LA homo-oligomers. A total of 216 soil samples were screened on the basis of clear zone formation on agar plates containing emulsified P(64 mol% D-LA-co-3HB). The 16S rRNA analysis of the isolated bacteria resulted in the identification of eight Variovorax, three Acidovorax, and one Burkholderia strains, which are closely related to previously identified natural PHA-degrading bacteria. These bacteria nearly consumed the P(D-LA-co-3HB) emulsion in the liquid culture; however, a small amount of the D-LA fraction remained unconsumed, which should be attributable to the D-LA-clustering structure in the copolymer. Cultivation of the isolated bacteria with the D-LA homo-oligomers revealed that the oligomers with a degree of polymerization (DP) ranging from 10 to 30 were partly consumed by six Variovorax and one Acidovorax strains. In contrast, the oligomers with DP ranging from 20 to 60 were not consumed by the isolated bacteria. These results indicate that D-LA homo-oligomers with DP higher than approximately 20 are hardly degraded by the soil bacteria. Molecular dynamic simulation of the D-LA homo-oligomers indicated that the upper limit of DP is likely to be determined by the conformational structure of the oligomers in water. The information obtained in this study will be useful for the molecular design of biodegradable D-LA-containing polymers

Disproportionation of a 2,2-Diphenyl-1-Picrylhydrazyl Radical as a Model of Reactive Oxygen Species Catalysed by Lewis and/or Brønsted Acids

Electron-transfer disproportionation of a 2,2-diphenyl-1-picrylhydrazyl radical (DPPH˙) occurred in the presence of Sc(3+) acting as a strong Lewis acid in deaerated acetonitrile. In contrast, in the case of weaker Lewis acids than Sc(3+), such as Mg(2+) and Li(+), external protons from acetic acid were required for the disproportionation of DPPH˙ to occur

Potentiality of multiple modalities for single-cell analyses to evaluate the tumor microenvironment in clinical specimens

Abstract Single-cell level analysis is powerful tool to assess the heterogeneity of cellular components in tumor microenvironments (TME). In this study, we investigated immune-profiles using the single-cell analyses of endoscopically- or surgically-resected tumors, and peripheral blood mononuclear cells from gastric cancer patients. Furthermore, we technically characterized two distinct platforms of the single-cell analysis; RNA-seq-based analysis (scRNA-seq), and mass cytometry-based analysis (CyTOF), both of which are broadly embraced technologies. Our study revealed that the scRNA-seq analysis could cover a broader range of immune cells of TME in the biopsy-resected small samples of tumors, detecting even small subgroups of B cells or Treg cells in the tumors, although CyTOF could distinguish the specific populations in more depth. These findings demonstrate that scRNA-seq analysis is a highly-feasible platform for elucidating the complexity of TME in small biopsy tumors, which would provide a novel strategies to overcome a therapeutic difficulties against cancer heterogeneity in TME