Kumamoto University

About: Kumamoto University is a education organization based out in Kumamoto, Kumamoto, Japan. It is known for research contribution in the topics: Cancer & Population. The organization has 19602 authors who have published 35513 publications receiving 901260 citations. The organization is also known as: Kumamoto Daigaku.

A randomised phase III trial comparing gemcitabine with surgery-only in patients with resected pancreatic cancer: Japanese Study Group of Adjuvant Therapy for Pancreatic Cancer

Abstract: A randomised phase III trial comparing gemcitabine with surgery-only in patients with resected pancreatic cancer: Japanese Study Group of Adjuvant Therapy for Pancreatic Cancer

Cell fusion-independent differentiation of neural stem cells to the endothelial lineage

Abstract: Somatic stem cells have been claimed to possess an unexpectedly broad differentiation potential (referred to here as plasticity) that could be induced by exposing stem cells to the extracellular developmental signals of other lineages in mixed-cell cultures1,2,3,4,5,6. Recently, this and other experimental evidence supporting the existence of stem-cell plasticity have been refuted because stem cells have been shown to adopt the functional features of other lineages by means of cell-fusion-mediated acquisition of lineage-specific determinants (chromosomal DNA) rather than by signal-mediated differentiation1,2,5,7,8. In this study we co-cultured mouse neural stem cells (NSCs), which are committed to become neurons and glial cells9,10, with human endothelial cells, which form the lining of blood vessels11. We show that in the presence of endothelial cells six per cent of the NSC population converted to cells that did not express neuronal or glial markers, but instead showed the stable expression of multiple endothelial markers and the capacity to form capillary networks. This was surprising because NSCs and endothelial cells are believed to develop from the ectoderm and mesoderm, respectively. Experiments in which endothelial cells were killed by fixation before co-culture with live NSCs (to prevent cell fusion) and karyotyping analyses, revealed that NSCs had differentiated into endothelial-like cells independently of cell fusion. We conclude that stem-cell plasticity is a true characteristic of NSCs and that the conversion of NSCs to unanticipated cell types can be accomplished without cell fusion.

Mice with disrupted GM2/GD2 synthase gene lack complex gangliosides but exhibit only subtle defects in their nervous system

Abstract: Gangliosides, sialic acid-containing glycosphingolipids, are abundant in the vertebrate (mammalian) nervous system. Their composition is spatially and developmentally regulated, and gangliosides have been widely believed to lay essential roles in establishment of the nervous system, especially in neuritogenesis and synaptogenesis. However, this has never been tested directly. Here we report the generation of mice with a disrupted beta 1,4-N-acetylgalactosaminyltransferase (GM2/GD2 synthase; EC 2.4.1.92) gene. The mice lacked all complex gangliosides. Nevertheless, they did not show any major histological defects in their nervous systems or in gross behavior. Just a slight reduction in the neural conduction velocity from the tibial nerve to the somatosensory cortex, but not to the lumbar spine, was detected. These findings suggest that complex gangliosides are required in neuronal functions but not in the morphogenesis and organogenesis of the brain. The higher levels of GM3 and GD3 expressed in the brains of these mutant mice may be able to compensate for the lack of complex gangliosides.

Alkylperoxyl radical-scavenging activity of various flavonoids and other phenolic compounds: implications for the anti-tumor-promoter effect of vegetables.

Abstract: We recently reported that alkylperoxyl radical (ROO•) enhanced carcinogenesis in rats treated with carcinogen (Sawa et al. Cancer Epidemiol. Biomarkers Prev. 1998, 7, 1007−1012), and the tumor promoting action of ROO• could be reduced by addition of hot-water extracts of vegetables (Maeda et al. Jpn. J. Cancer Res. 1992, 83, 923−928). Here we described the ROO•-scavenging activity of flavonoids and nonflavonoid phenolics and their role in anti-tumor-promoter effects. A model molecular species, ROO•, was generated from tert-butyl hydroperoxide (t-BuOOH) and heme iron, and the scavenging of t-BuOO• was determined by (a) bioassay based on the bactericidal action of ROO•, (b) luminol-enhanced chemiluminescence, and (c) electron spin resonance. Of 17 authentic plant phenolics tested, 9 compounds (including rutin, chlorogenic acid, vanillin, vanillic acid, neohesperidin, gallic acid, shikimic acid, rhamnetin, and kaempferol) showed remarkably high ROO•-scavenging activity. Some of them were detected and quantif...