Kanazawa University is a national university of Japan located in the city of Kanazawa, the capital of Ishikawa Prefecture.Kanazawa University is divided into two main campuses: Kakuma and Takaramachi. Student enrollment is about 11,000 including 350 international students. Wikipedia.
Hayashi Y.,Kanazawa University
Coordination Chemistry Reviews | Year: 2011
Many synthetic methods for heteropolyoxovanadates and lacunary polyoxovanadates have been developed in recent years. We outline various approaches used to produce new polyoxovanadate species, including heterometal-incorporated complexes of tetravanadates, hexavanadates, decavanadates and dodecavanadates. In particular, three types of synthetic routes are explored; based on (i) coordination of metavanadate species to transition metal cations, (ii) oxidation of reduced polyoxovanadates, and (iii) template synthesis. Metavanadate species can coordinate to metal cations as inorganic macrocyclic ligands to form heteropolyoxovanadates. The incorporation of a heterometal cation into decavanadates has also been reported. The oxidation reaction of reduced polyoxovanadates provides a new route to the formation of the lacunary polyoxovanadates, which can serve as inorganic host molecules. Dodecavanadates are bowl-type molecules of particular structural interest; a chloride anion can be incorporated into the bowl through a template synthesis. Structural transformations between these dodecavanadate species and alkoxopolyoxovanadates are also described. © 2011 Elsevier B.V.
Yamashima T.,Kanazawa University
Progress in Lipid Research | Year: 2012
Despite the well-known effects of polyunsaturated fatty acids (PUFA) on synaptic plasticity, PUFA-modulated signaling mechanism is unknown especially in humans. In 2003, three groups reported that G protein-coupled receptor 40 (GPR40) induces Ca2+ mobilization in response to PUFA. Although GPR40 gene is abundantly expressed in the primate brain, it is negligible in the rodent brain. Diverse PUFA including docosahexaenoic acid (DHA) are in vitro ligands for GPR40, but nobody knows its downstream pathway. cAMP-response element binding protein (CREB) is a transcription factor transmitting extracellular signals to change gene expression. Although PUFA, transported by fatty acid binding proteins (FABP), directly phosphorylate CREB in rodents, hydrophobic PUFA cannot access to the nuclei in the primate neurons because of lack of a cargo protein. Ischemia-enhanced adult neurogenesis in monkeys showed concomitant upregulation of GPR40 and phosphorylated CREB, and localization of both in the neurogenic niche. Here, 'PUFA-GPR40-CREB signaling' hypothesis was highlighted as a regulator of adult neurogenesis specific for primates. © 2012 Elsevier Ltd. All rights reserved.
Yamashima T.,Kanazawa University
Journal of Neurochemistry | Year: 2012
Necrosis has long been considered accidental and uncontrolled, but during the last decade, it became clear that necrosis is also a well-orchestrated form of cell demise, being as well programmed as apoptosis. To explain the mechanism of neuronal necrosis after ischemia/reperfusion, the 'calpain-cathepsin hypothesis' formulated in 1998 postulates that the post-ischemic μ-calpain activation compromises integrity of the lysosomal membrane, thereby leading to cathepsin spillage. Another cause of the lysosomal rupture occurring during reperfusion is reactive oxygen species (ROS) that generate 4-hydroxy-2-nonenal (HNE) by oxidation of membrane fatty acids such as linoleic and arachidonic acids. HNE is an endogenous neurotoxin, because HNE-induced carbonylation of the substrate protein shows loss of its function. However, the molecular mechanisms of lysosomal membrane breakdown are still poorly understood; especially, the biochemical cascade how μ-calpain and ROS work together to disrupt lysosomal membrane has remained unclarified. Three independent proteomic analyses of cerebral ischemia, glaucoma, or mild cognitive impairment in primates have altogether suggested that the common substrate of calpain and/or ROS is heat-shock protein 70.1 (Hsp70.1; simply Hsp70, also called Hsp72 or HSPA1), a major protein of the human Hsp70 family. Hsp70.1 serves cytoprotective roles as a guardian of the lysosomal membrane integrity by assisting sphingomyelin degradation or maintaining proper protein folding and recycling as a chaperone. However, calpain-mediated cleavage of Hsp70.1, especially after its carbonylation because of the oxidative stresses, can induce lysosomal rupture. Furthermore, Hsp70.1 dysfunction activates nuclear factor-kappaB (NF-κB) signaling that can also promote neurodegeneration. By focusing on Hsp70.1 and related lysosomal factors, this review describes rationale of lysosomal destabilization and rupture for executing programmed neuronal necrosis. © 2011 The Author.
Arai S.,Kanazawa University
Earth and Planetary Science Letters | Year: 2013
Podiform chromitites have been interpreted as a peridotite/melt reaction product within the upper mantle (= low-P chromitites). Some of them, however, contain ultrahigh-pressure (UHP) minerals such as diamond and coesite (= UHP chromitites). The UHP chromitites can be produced by deep recycling of low-P chromitites via mantle convection. Carbon-rich UHP minerals were changed from fluidal C species (e.g., CO2) metasomatically entrapped during the travel of chromitites within the mantle. Lamellae of coesite and other silicates observed in UHP chromite were possibly originated from globular inclusions of hydrous minerals and pyroxenes, which are common in low-P chromitites. Platinum-group element (PGE) sulfides, which commonly characterize the low-P chromitites, were converted to PGE metals or alloys by heating on their decompression during mantle convection. Peculiar igneous textures, e.g., nodular textures, characteristic of low-P chromitites can be preserved even after compression and subsequent decompression during recycling because of possible absence of reactions between olivine and chromite or their high-P polymorphs. The UHP chromities can thus be an indicator of mantle convection; UHP minerals in chromitite may support the two-layer convection model. © 2013 Elsevier B.V.
Ando T.,Kanazawa University
Nanotechnology | Year: 2012
High-speed atomic force microscopy (HS-AFM) is now materialized. It allows direct visualization of dynamic structural changes and dynamic processes of functioning biological molecules in physiological solutions, at high spatiotemporal resolution. Dynamic molecular events unselectively appear in detail in an AFM movie, facilitating our understanding of how biological molecules operate to function. This review describes a historical overview of technical development towards HS-AFM, summarizes elementary devices and techniques used in the current HS-AFM, and then highlights recent imaging studies. Finally, future challenges of HS-AFM studies are briefly discussed. © 2012 IOP Publishing Ltd.