Cortical representation area of human dental pulp

博士（歯学）・第1662号（甲第958号）・平成18年3月31

Localization of palatal area in human somatosensory cortex

博士（歯学）・第1661号（甲第957号）・平成18年3月31日http://jdr.iadrjournals.org/cgi/content/full/86/3/26

Plasma Membrane Ca 2+-ATPase in Rat and Human Odontoblasts Mediates Dentin Mineralization

Intracellular Ca(2+) signaling engendered by Ca(2+) influx and mobilization in odontoblasts is critical for dentinogenesis induced by multiple stimuli at the dentin surface. Increased Ca(2+) is exported by the Na(+)–Ca(2+) exchanger (NCX) and plasma membrane Ca(2+)–ATPase (PMCA) to maintain Ca(2+) homeostasis. We previously demonstrated a functional coupling between Ca(2+) extrusion by NCX and its influx through transient receptor potential channels in odontoblasts. Although the presence of PMCA in odontoblasts has been previously described, steady-state levels of mRNA-encoding PMCA subtypes, pharmacological properties, and other cellular functions remain unclear. Thus, we investigated PMCA mRNA levels and their contribution to mineralization under physiological conditions. We also examined the role of PMCA in the Ca(2+) extrusion pathway during hypotonic and alkaline stimulation-induced increases in intracellular free Ca(2+) concentration ([Ca(2+)](i)). We performed RT-PCR and mineralization assays in human odontoblasts. [Ca(2+)](i) was measured using fura-2 fluorescence measurements in odontoblasts isolated from newborn Wistar rat incisor teeth and human odontoblasts. We detected mRNA encoding PMCA1–4 in human odontoblasts. The application of hypotonic or alkaline solutions transiently increased [Ca(2+)](i) in odontoblasts in both rat and human odontoblasts. The Ca(2+) extrusion efficiency during the hypotonic or alkaline solution-induced [Ca(2+)](i) increase was decreased by PMCA inhibitors in both cell types. Alizarin red and von Kossa staining showed that PMCA inhibition suppressed mineralization. In addition, alkaline stimulation (not hypotonic stimulation) to human odontoblasts upregulated the mRNA levels of dentin matrix protein-1 (DMP-1) and dentin sialophosphoprotein (DSPP). The PMCA inhibitor did not affect DMP-1 or DSPP mRNA levels at pH 7.4–8.8 and under isotonic and hypotonic conditions, respectively. We also observed PMCA1 immunoreactivity using immunofluorescence analysis. These findings indicate that PMCA participates in maintaining [Ca(2+)](i) homeostasis in odontoblasts by Ca(2+) extrusion following [Ca(2+)](i) elevation. In addition, PMCA participates in dentinogenesis by transporting Ca(2+) to the mineralizing front (which is independent of non-collagenous dentin matrix protein secretion) under physiological and pathological conditions following mechanical stimulation by hydrodynamic force inside dentinal tubules, or direct alkaline stimulation by the application of high-pH dental materials

SPring-8 LEPS2 beamline: A facility to produce a multi-GeV photon beam via laser Compton scattering

We have constructed a new laser-Compton-scattering facility, called the LEPS2 beamline, at the 8-GeV electron storage ring, SPring-8. This facility provides a linearly polarized photon beam in a tagged energy range of 1.3--2.4 GeV. Thanks to a small divergence of the low-emittance storage-ring electrons, the tagged photon beam has a size (sigma) suppressed to about 4 mm even after it travels about 130 m to the experimental building that is independent of the storage ring building and contains large detector systems. This beamline is designed to achieve a photon beam intensity higher than that of the first laser-Compton-scattering beamline at SPring-8 by adopting the simultaneous injection of up to four high-power laser beams and increasing a transmittance for the long photon-beam path up to about 77%. The new beamline is under operation for hadron photoproduction experiments