Uncommon case of cytopathological features of sialadenoma papilliferum.

Sialadenoma papilliferum, a benign and rare salivary gland neoplasm, accounts for 0.4%-1.2% of all salivary gland tumors and occurs primarily in minor salivary glands of the oral cavity. Here, we report a case of sialadenoma papilliferum and its associated cytological findings. A papillary tumor was incidentally detected on the palate of an 86-year-old Japanese man. Conventional oral exfoliative cytology was performed; the cytology smear exhibited epithelial clusters composed of atypical epithelial cells with a high nuclear/cytoplasm ratio and arranged in sheet or small papillary-like projections. Cytoplasmic vacuoles were also observed in the papillae. It was difficult to make a definitive diagnosis due to the presence of uncommon cytological features. The excisional biopsy specimen revealed histological features characteristic of sialadenoma papilliferum. Mutational analysis detected BRAFV600E mutation, which confirmed the diagnosis of sialadenoma papilliferum. To the best of our knowledge, no prior cytomorphological evaluations of sialadenoma papilliferum have been reported in detail. Oral exfoliative cytology specimens from salivary gland tumors can demonstrate uncommon cytomorphological features. A differential diagnosis of sialadenoma papilliferum can be based on the observation of mildly atypical epithelial cells that form small papillary-like structures.

Formulation and evaluation of bitter taste-masked orally disintegrating tablets of high memantine hydrochloride loaded granules coated with polymer via layering technique.

Orally disintegrating tablets (ODTs) improve patient adherence as they can easily disintegrate in the presence of small amount of saliva. However, the bitter taste of the active pharmaceutical ingredient in ODTs reduces patient compliance. The present study aimed to formulate bitter taste-masked ODTs containing high-dose of memantine hydrochloride (MTN) to achieve a balance between bitterness suppression and dissolution rate or disintegration time and mechanical strength. The high MTN-loaded granules were prepared using a fluidized bed granulator. Taste-masking granules coated with the selected polymer were prepared using the layering technique. Three ODTs, composed of granules coated with different polymers, were prepared. The ODT prepared using granules coated with enteric polymers showed the fastest collapse time (>20 s). Dissolution rates of ODTs composed of enteric polymers were reduced by 5 min compared with ODTs composed of non-coated or coated with water-insoluble polymer granules. X-ray computed tomography analysis revealed that low density distribution of ODTs with enteric polymer granules may result in faster disintegration time. Although ODT prepared using enteric polymers had the fastest collapse time, its change in membrane potential caused by adsorption (CPA), corresponding to aftertaste, was the lowest among formulations. This CPA value was lower than the bitterness threshold.

Physiological polyspermy: Selection of a sperm nucleus for the development of diploid genomes in amphibians.

The union between a sperm and an egg nucleus in egg fertilization is necessary to mix genetic materials to create a new diploid genome for the next generation. In most animals, only one sperm is incorporated into the egg (monospermy), but several animals exhibit physiological polyspermy in which several sperms enter the egg during normal fertilization. However, only one sperm nucleus forms the zygote nucleus with the egg nucleus, even in a polyspermic egg. The cellular and molecular mechanisms involved in the selection of sperm nuclei in the egg cytoplasm have been well investigated in urodele amphibians. The principal sperm nucleus develops a larger sperm aster and contacts the egg nucleus to form a zygote nucleus, whereas other accessory sperm nuclei are unable to approach the egg nucleus. The diploid zygote nucleus induces cleavage and participates in embryonic development, whereas the accessory sperm nuclei undergo pyknosis and degenerate. We propose several models to account for the mechanisms of the selection of one sperm nucleus and the degeneration of accessory sperm nuclei. The roles of physiological polyspermy in animal reproduction are discussed by comparison with other polyspermic species.

Origins of sp(3)C peaks in C1s X-ray Photoelectron Spectra of Carbon Materials.

X-ray photoelectron spectroscopy (XPS) is among the most powerful techniques to analyze defective structures of carbon materials such as graphene and activated carbon. However, reported assignments of defects, especially sp(3)C and sp(2)C, are questionable. Most reports assign sp(3)C peaks to be higher than sp(2)C peaks, whereas a few reports assign sp(3)C peaks to be lower than sp(2)C peaks. Our group previously reported that calculated binding energies of sp(3)C were basically lower than those of sp(2)C. This work clarified that one of the reasons for the prevailing ambiguous assignments of sp(3)C peaks is charging effects of diamond.