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Biomedical subjects

H Yamaji

Publications and source records attributed to H Yamaji.

22 records · Page 2Linked to original sources

Nondwarf rice seedling bioassay for gibberellins.

The use of nondwarf rice (Oryza sativa L.) cultivars treated with uniconazole as test plants for gibberellin (GA) bioassay instead of Tan-ginbozu dwarf rice variant was investigated. The sensitivity of six nondwarf rice cultivars to GAs was increased substantially by treatment of the seeds with uniconazole. The minimum detectable dose of a GA in the nondwarf cultivars treated with uniconazole was 1- to 1/10-fold of that in the nontreated Tanginbozu and 3- to 10-fold of that in uniconazole-treated Tanginbozu. The relative activity of several GAs on treated nondwarf rice cultivars was not largely different from that to Tan-ginbozu. Considering that seeds of nondwarf rice are available commercially, the nondwarf rice seedling assay would be useful as a simple assay for systematic analysis of GAs, and also as a routine teaching tool in high schools and universities.

Journal Article↗

Long-term cultivation of anchorage-independent animal cells immobilized within reticulated biomass support particles in a circulating bed fermentor.

Long-term cultivation of anchorage-independent animal cells immobilized within porous biomass support particles (BSPs) using a gas-stirred circulating bed fermentor (CBF) was investigated. Inoculation of mouse myeloma MPC-11 (ATCC CCL 167) cells into reticulated polyvinyl formal resin BSPs (3 x 3 x 3 mm; mean pore diameter, 60 microns; porosity, 0.88) and the repeated batch culture of inoculated cells were performed under gentle circulation of BSPs, induced by sparging air from the base of the fermentor. The glucose uptake rate of cells decreased in the initial period just after the start of circulation, since a relatively large number of cells leaked from the BSPs. After that period, the uptake rate gradually increased and the leakage of cells diminished. In the meantime, when inoculated cells were incubated statically by introducing air into days before circulating the BSPs, glucose consumption became very rapid and cell density in the BSPs reached at least 10(7) cells/cm3 BSP. Thus, a long-term cultivation without significant leakage of cells and with high cell density in BSPs was successfully achieved in the CBF-BSP system.

Animals↗

High spatial resolution CT with a synchrotron radiation system.

OBJECTIVE: We describe a monochromatic X-ray CT system using synchrotron radiation, which has been constructed employing a vertical wiggler beam line at the National Laboratory for High-Energy Physics in Tsukuba, Japan. This CT system was produced to facilitate examination of the microstructures of material and biological specimens. MATERIALS AND METHODS: The system provides excellent contrast and has a spatial resolution capacity ranging from 2 to 100 mm. In this preliminary experiment, the images of the rat were obtained at 36-mm slice thickness and 33.2-keV X-ray energy. RESULTS: The nasal cartilage, skull, and teeth of a live rat were clearly demonstrated with 36-mm spatial resolution. CONCLUSION: Using a monochromatic X-ray CT system with synchrotron radiation, detailed structures of rat skull were imaged clearly.

Animals↗