Morioki Fujitani

Regional distribution of parkinsonism-preventing endogenous tetrahydroisoquinoline derivatives and an endogenous parkinsonism-preventing substance-synthesizing enzyme in monkey brain.

1,2,3,4-Tetrahydroisoquinoline (TIQ) and 1-benzyl-1,2,3,4-tetrahydroisoquinoline (1BnTIQ), which exist in the brain of several mammalian species, are parkinsonism-inducing substances, and 1-methyl-1,2,3,4-tetrahydroisoquinoline (1MeTIQ), which is enzymatically synthesized in rat brain, is a parkinsonism-preventing substance. In this study, we examined the regional distribution of contents of TIQ, 1MeTIQ, and 1BnTIQ, and activity of 1MeTIQ-synthesizing enzyme in monkey brain. The TIQ and 1BnTIQ contents in cerebrum and substantia nigra, and the 1MeTIQ contents in striatum and substantia nigra were higher than those in other brain regions, and 1MeTIQ-synthetic activity was high in cerebrum and thalamus. We speculate that 1MeTIQ-synthesizing enzyme may play an important role in idiopathic Parkinsons disease.

Does Er:YAG or CO2 laser ablation of dentin affect the adhesive properties of resin bonding systems?

The aim of this study was to evaluate whether Er:YAG or CO2 laser ablation of dentin affects the early bond strengths of dentin bonding systems. Wedge-shaped defects were prepared in freshly extracted bovine teeth and were irradiated by Er:YAG (60 mJ, 10 pps) or CO2 (1 W, 0.3 s) laser. They were filled with various adhesives according to the respective manufacturers instructions, and were stored in distilled water at 37 °C for 24 h. The bond strength was examined with the micro-tensile bond test, whereas the interfacial ultrastructure was observed using scanning electron microscope (SEM) and transmission electron microscope (TEM). The interfacial properties were also characterized by light microscope (LM) especially on the Massons trichrome-stained specimens. Laser irradiation significantly reduced the bond strength. The smear layer could not be detected, and cracks and stratified structure like fish scales were observed on the surface of lased dentin. The resultant heat superficially denatured the dentinal collagen fibers. Removal of both the denatured layer and structural defects recovered the reduced bond strength of adhesives. It was concluded that Er:YAG or CO2 laser ablation of dentin affected the adhesive properties of resin bonding systems.

Cynomolgus monkey liver aldehyde oxidase: extremely high oxidase activity and an attempt at purification

Aldehyde oxidase (EC 1.2.3.1) in monkey (Macaca fascicularis) liver was characterized. Liver cytosol exhibited extremely high benzaldehyde and phthalazine oxidase activities based on aldehyde oxidase, compared with those of rabbits, rats, mice and guinea pigs. Monkey liver aldehyde oxidase showed broad substrate specificity distinct from that of the enzyme from other mammals. Purified aldehyde oxidase from monkey liver cytosol showed two major bands and two minor bands in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). These bands were also observed in Western blotting analysis using anti-rat aldehyde oxidase. The molecular mass of the enzyme was estimated to be 130-151 kDa by SDS-PAGE, and to be about 285 kDa by HPLC gel filtration. The results suggest that isoforms of aldehyde oxidase exist in monkey livers.