Akiko Mantoku

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To understand how humans adapt to the space environment, many experiments can be conducted on astronauts as they work aboard the Space Shuttle or the International Space Station (ISS). We also need animal experiments that can apply to human models and help prevent or solve the health issues we face in space travel. The Japanese medaka (Oryzias latipes) is a(More)
A beta-lactamase was purified to an apparently homogeneous state from Streptomyces cacaoi. The molecular weight calculated from the mobility in sodium dodecyl sulfate polyacrylamide gel electrophoresis was 34,000. pI was 4.7 and the optimal pH was 6.5. The optimum temperature was found to be between 40 degrees C and 45 degrees C, but the enzyme lost(More)
Inactivation of a beta-lactamase of Streptomyces cacaoi by clavulanic acid and PS-5 was investigated and compared with that of a beta-lactamase of Bacillus cereus. Inhibition of the enzymes induced by clavulanic acid and the beta-lactam antibiotic PS-5 was found to be progressive with time. However, the degree of inhibition of the beta-lactamase from S.(More)
The bone mineral density (BMD) of astronauts decreases specifically in the weight-bearing sites during spaceflight. It seems that osteoclasts would be affected by a change in gravity; however, the molecular mechanism involved remains unclear. Here, we show that the mineral density of the pharyngeal bone and teeth region of TRAP-GFP/Osterix-DsRed double(More)
Tooth replacement in polyphyodont is a well-organized system for maintenance of homeostasis of teeth, containing the dynamic structural change in skeletal tissues such as the attachment bone, which is the supporting element of teeth. Histological analyses have revealed the character of tooth replacement, however, the cellular mechanism of how skeletal(More)
Inhibition of a beta-lactamase of Streptomyces cacaoi by CP-45,899, izumenolide and cephamycins was investigated and compared with that of a beta-lactamase of Bacillus cereus. S. cacaoi enzyme could not hydrolyze CP-45,899. Instead, hydrolysis of benzylpenicillin by the enzyme was inhibited in the presence of CP-45,899. Although inhibition increased(More)
Bone loss is a serious problem in spaceflight; however, the initial action of microgravity has not been identified. To examine this action, we performed live-imaging of animals during a space mission followed by transcriptome analysis using medaka transgenic lines expressing osteoblast and osteoclast-specific promoter-driven GFP and DsRed. In live-imaging(More)
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