Fusao Tomita

Bio: Fusao Tomita is an academic researcher from Hokkaido University. The author has contributed to research in topics: Fermentation & Magnaporthe grisea. The author has an hindex of 46, co-authored 176 publications receiving 7692 citations. Previous affiliations of Fusao Tomita include Ajinomoto.

Rhamnolipids produced by Pseudomonas aeruginosa grown on n-paraffin (mixture of C 12 , C 13 and C 14 fractions).

Abstract: Two kinds of glycolipids (R-l and R-2) were produced in the culture media by several strains of Pseudomonas aeruginosa when grown on n paraffin (mixture of C12, C13. and C14 fractions). These compounds were isolated through the extraction of the culture broth with ethylacetate and the chromatography on silicic acid column. On the basis of chemical analysis, these lipids were characterized as 2-O-α-L-rhamnopyranosyl-α-L-rhamnopyranosyl-β- hydroxydecanoyl-β-hydroxydecanoate (R-l) and L-α-rhamnopyranosyl-β- hydroxydecanoyl-β-hydroxydecanoate (R-2). Bactericidal activity of R-2 which is postulated to be a precursor of R-1 was remarked against grampositive bacteria. Further, these compounds also demonstrated mycoplasmacidal and antiviral activities in vitro.

Melibiose, difructose anhydride III and difructose anhydride IV enhance net calcium absorption in rat small and large intestinal epithelium by increasing the passage of tight junctions in vitro

Abstract: An Ussing chamber technique was used to determine the effects of three indigestible disaccharides on net Ca transport from the luminal side to the basolateral side of isolated preparations of jejunal, ileal, cecal and colonic epithelium in rats. Permeability of Lucifer Yellow (LY) and transepithelial electrical resistance (TEER), which are indicators of intercellular passage of the intestinal mucosa, were also determined. The concentrations of Ca in the serosal and mucosal media were 1.25 mmol/L and 10 mmol/L, respectively. After a 30-min incubation, the net Ca transport, LY passage and TEER were determined. In the control experiment, LY permeability was lowest, and TEER value was highest in the colon. The addition of 1-100 mmol/L melibiose, difructose anhydride (DFA)III, or DFAIV to the mucosal medium increased the net Ca absorption and LY permeability dose-dependently in the jejunum, ileum, cecum and colon preparations. Melibiose decreased TEER dose-dependently in the jejunum and cecum, but not in the ileum and colon. DFAIII decreased TEER dose-dependently in the jejunum, cecum and colon, but not in the ileum. DFAIV decreased TEER dose-dependently in all four intestinal portions. Positive linear relationships were found between net Ca transport and LY passage in all portions of the intestine, whereas negative linear relationships were found between net Ca absorption and TEER. We concluded that the three indigestible saccharides directly affect the epithelial tissue and activate the passage of tight junctions, thereby promoting Ca absorption in the small and large intestine in vitro.

Protein kinases--the major drug targets of the twenty-first century?

Abstract: Protein phosphorylation regulates most aspects of cell life, whereas abnormal phosphorylation is a cause or consequence of disease. A growing interest in developing orally active protein-kinase inhibitors has recently culminated in the approval of the first of these drugs for clinical use. Protein kinases have now become the second most important group of drug targets, after G-protein-coupled receptors. Here, I give a personal view of some of the most important advances that have shaped this field.