Masayuki Yoshikawa

Learn More
It has been previously documented that the thermolysin-digest of "Katsuo-bushi", a Japanese traditional food processed from dried bonito possesses potent inhibitory activity against angiotensin I-converting enzyme (ACE). The present authors isolated eight kinds of ACE-inhibitory peptides from it. Of these isolated peptides, LKPNM (IC50 = 2.4 microM) was(More)
During the interval from September through early December 2005, the Hayabusa spacecraft was in close proximity to near-Earth asteroid 25143 Itokawa, and a variety of data were taken on its shape, mass, and surface topography as well as its mineralogic and elemental abundances. The asteroid's orthogonal axes are 535, 294, and 209 meters, the mass is 3.51 x(More)
Autosomal recessive juvenile parkinsonism (AR-JP) is a distinct clinical entity characterized by a selective degeneration of nigral neurons. Recently, the parkin gene responsible for AR-JP has been identified. Now, we report the subcellular localization of Parkin protein in patients with AR-JP or Parkinson's disease (PD) and in controls by immunoblotting(More)
Following the characterization of myrciacitrins I and II and myrciaphenones A and B, three new flavanone glucosides, myrciacitrins III, IV, and V, were isolated from the leaves of Brazilian Myrcia multiflora. The structures of new myrciacitrins were elucidated on the basis of physicochemical and chemical evidence. Myrciacitrins were found to show potent(More)
Expression of invasion genes encoded by the large 230-kb plasmid of Shigella flexneri is controlled by the virB gene, which is itself activated by another regulator, virF. Transcription of the invasion genes is temperature regulated, since they are activated in bacteria grown at 37 but not at 30 degrees C. Recently, we have shown that the thermoregulated(More)
Lines of evidence suggested a possible link between leptin and hepatic fibrosis; however, whether leptin modulates the fibrogenesis in the liver remains unclear. The purpose of this study, therefore, was to evaluate the effect of leptin on inflammatory and profibrogenic responses in the liver caused by hepatotoxic chemicals. Male C57Bl/6 mice were given(More)
STUDY OBJECTIVE To assess the characteristics of airway inflammation in patients with COPD. METHODS We measured the sputum concentration of interleukin-8 (IL-8), a chemokine involved in the migration and activation of neutrophils and eosinophils. We also measured myeloperoxidase (MPO) as a parameter of neutrophil activity and eosinophil cationic protein(More)
We have identified a region (virG) on the 230 kb virulence plasmid of S. flexneri that is required for cell-to-cell spread of the bacterium. Tn5 insertions into this region result in avirulent mutants that can initially invade and multiply in epithelial cells, but tend to lose active movement and tend to localize within the cytoplasm, where they are(More)
We investigated the antihyperglycemic action of a crude saponin fraction and five triterpene glycosides (gymnemic acids I-IV and gymnemasaponin V) derived from the methanol extract of leaves of Gymnema sylvestre R. BR. (Asclepiadaceae) in streptozotocin (STZ)-diabetic mice. The saponin fraction (60mg/kg) reduced blood glucose levels 2 4h after the(More)
Salacia (S.) reticulata, a Hippocrateaceae plant distributed in Sri Lankan and Indian forests, has been used as a supplementary food in Japan to prevent obesity and diabetes. We examined the antiobesity effects of the hot water-soluble extract (SRHW) from the roots of S. reticulata using obese rat models and an in vitro study. Body weight (P = 0.07) and(More)