The aim of this study was to show the reaction varieties of human tooth enamel and dentin with a carbonated soft drink, Sprite. After one week exposing into the soft drink, the sliced tooth specimens were examined by macroscopic and microscopic and then carried out the micro X-ray diffraction analysis using a 100 m diameter X-ray beam. The macroscopic and microscopic results showed the wide varieties from the one showing a very slight increase white-spot areas in the enamel to the another showing almost complete decay of the enamel. The crystallites in the examined enamel and dentin changed drastically as follows; the one enamel sample showed the decrease of crystal amount and some ionic substitutions, and the another dentin sample showed the increase in crystallinity and ionic substitutions. These results clearly showed that the original tooth enamel and dentin had their own crystallographic properties differing from each others. This study provided a crystallographic basic data which will be applied to a tayler-made individual preventive dentistry in near future.

Catechol O-methyltransferase (COMT) is known as an important drug-target protein in the field of Parkinson's disease. All clinically approved COMT inhibitors bring a 5-substituted-3-nitrocatechol ring as a pharmacophore, and they bind to COMT with S-adenosylmethionine (SAM) and an Mg 2 ion to form a quaternary complex (COMT/SAM/Mg 2 /inhibitor). However, structural information about such quaternary complexes is only available for a few inhibitors. Here, a new crystal structure of COMT complexed with nitecapone (5), SAM and Mg 2 is revealed. Comparison of the structures of these complexes indicates that conformation of the catechol binding pocket is almost constant regardless of structure of the inhibitors. The only restriction of the side chain of inhibitors (i.e., the substituent at the 5-position of 3-nitrocatechol) seems to be that it does not make steric repulsion with COMT. However, recent crystallographic and biochemical studies suggest that COMT is a flexible protein, and its conformational flexibility seems crucial for its catalytic process. Based on this information, implications of these quaternary inhibitor complexes were investigated. Met 40 in the α2α3-loop makes atomic contacts with SAM or S-adenosylhomocysteine and the 3-position of the catechol inhibitor. This interaction seems to play a critical role in the affinity of the inhibitor and to stabilize the COMT/SAM/Mg 2 /nitrocatechol inhibitor complex by fixing the flexible α2α3-loop.

The salivary glands help to keep the mouth and other parts of the digestive system moist. There have been only a few reports on the salivary glands of the marsupial gray short-tailed opossum(Monodelphis domestica). The aim of this study was to reveal the ultrastructure of the parotid and submandibular glands in the gray short-tailed opossum using transmission electron microscopy(TEM). Using TEM, the parotid glands were found to consist only of serous acinar cells. Secretory granules were highly electron dense. The submandibular glands were composed of both serous and mucous acinar cells, showing a mixture of glands. Also, the submandibular glands possessed special serous cells. Secretory granules were divided into homogeneous density type, two biphasic types and annual ring types. The properties of the granules were different in each cell type. However, some cells contained a mixture of every type of granule. It appeared that the variety of granules in the special serous cells represented stages in the cell cycle and was not a property of the cell.Striated ducts of submandibular glands consisted both of columnar epithelium with or without basal infoldings, although typical striated ducts were found in parotid glands.

Recently, earthworms have become a useful model for research into the immune system, and it is expected that results obtained using this model will shed light on the sophisticated vertebrate immune system and the evolution of the immune response, and additionally help identify new biomolecules with therapeutic applications. However, for earthworms to be used as a genetic model of the invertebrate immune system, basic molecular and genetic resources, such as an expressed sequence tag (EST) database, must be developed for this organism. Next-generation sequencing technologies have generated EST libraries by RNA-seq in many model species. In this study, we used Illumina RNA-sequence technology to perform a comprehensive transcriptome analysis using an RNA sample pooled from sterile-cultured Eisenia andrei. All clean reads were assembled de novo into 41,423 unigenes using the Trinity program. Using this transcriptome data, we performed BLAST analysis against the GenBank non-redundant (NR) database and obtained a total of 12,285 significant BLAST hits. Furthermore, gene ontology (GO) analysis assigned 78 unigenes to 24 immune class GO terms. In addition, we detected a unigene with high similarity to beta-1,3-glucuronyltransferase 1 (GlcAT-P), which mediates a glucuronyl transfer reaction during the biosynthesis of the carbohydrate epitope HNK-1 (human natural killer-1, also known as CD57), a marker of NK cells. The identified transcripts will be used to facilitate future research into the immune system using E. andrei.

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