Cementum structure in Beluga whale teeth.

Unlabelled: A large fraction of the volume of Beluga whale (Delphinapterus leucas) teeth consists of cementum, a mineralized tissue which grows throughout the life of the animal and to which the periodontal ligaments attach. Annular growth bands or growth layer groups (GLGs) form within Beluga cementum, and this study investigates GLG structure using X-ray fluorescence mapping and X-ray diffraction mapping with microbeams of synchrotron radiation. The Ca and Zn fluorescent intensities and carbonated hydroxyapatite (cAp) diffracted intensities rise and fall together and match the light-dark bands visible in transmitted light micrographs.

Bovine and equine peritubular and intertubular dentin.

Dentin contains 1-2μm diameter tubules extending from the pulp cavity to near the junction with enamel. Peritubular dentin (PTD) borders the tubule lumens and is surrounded by intertubular dentin (ITD). Differences in PTD and ITD composition and microstructure remain poorly understood.

Near tubule and intertubular bovine dentin mapped at the 250 nm level.

In this study, simultaneous diffraction and fluorescence mapping with a (250nm)(2), 10.1keV synchrotron X-ray beam investigated the spatial distribution of carbonated apatite (cAp) mineral and elemental Ca (and other cations including Zn) around dentin tubules. In 1μm thick sections of near-pulp root dentin, where peritubular dentin (PTD) is newly forming, high concentrations of Zn, relative to those in intertubular dentin (ITD), were observed adjacent to and surrounding the tubule lumens.

Silicone occlusive treatment of hypertrophic scar in the rabbit model.

Background: Hypertrophic scar formation at sites of healed cutaneous injury often produces functional and esthetic deficits. Treatments have been limited in part by a lack of understanding of scar etiology and the lack of animal models of hypertrophic scarring. Silicone dressing is reported to provide positive outcomes with respect to a reduction in scar hypertrophy and an improvement in color differences, although the exact mechanism is unknown.

Regulation of vocal fold transepithelial water fluxes.

Vocal fold hydration is critical to phonation. We hypothesized that the vocal fold generates bidirectional water fluxes, which are regulated by activity of the Na(+)-K(+)- ATPase. Western blots and immunohistochemistry demonstrated the presence of the alpha-subunit Na(+)-K(+)-ATPase in the canine vocal fold (n = 11).