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). Luminal cells, basal and adjacent one to two layers of suprabasal cells within stratified squamous epithelium, were immunopositive, as well as basolateral membranes of submucosal seromucous glands underlying transitional epithelia. Canine (n = 6) and ovine (n = 14) vocal fold mucosae exhibited transepithelial potential differences of 8.1 +/- 2.8 and 9.3 +/- 1.3 mV (lumen negative), respectively. The potential difference and short-circuit current (ovine = 31 +/- 4 microA/cm(2); canine = 41 +/- 10 microA/cm(2)) were substantially reduced by luminal administration of 75 microM acetylstrophanthidin (P < 0.05). Ovine (n = 7) transepithelial water fluxes decreased from 5.1 +/- 0.3 to 4.3 +/- 0.3 microl x min(-1) x cm(-2) from the basal to luminal chamber and from 5.2 +/- 0.2 to 3.9 +/- 0.3 microl x min(-1) x cm(-2) from the luminal to basal chamber by luminal acetylstrophanthidin (P < 0.05). The presence of the Na(+)-K(+)-ATPase in the vocal fold epithelium and the electrolyte transport derived from its activity provide the intrinsic mechanisms to regulate cell volume as well as vocal fold hydration.

Background: Hypertrophic scar formation at sites of healed cutaneous injury often produces functional and esthetic deficits. Treatments have been limited in part by (Aesthetic Surg J 2002;22:147-153.)

No abstract

In this study, simultaneous diffraction and fluorescence mapping with a (250 nm)2, 10.1 keV 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 1 μm 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. Some but not all tubules exhibited hypercalcified collars (high Ca signal relative to the surrounding ITD), and, when present, the zone of high Ca did not extend around the tubule. Diffraction rings from cAp 00.2 and 11.2+21.1+30.0 reflections were observed, and cAp was the only crystal phase detected. Profiles of Ca, Zn and cAp diffracted intensities showed the same transitions from solid to tubule lumen, indicating the same cAp content and organization in ITD far from the tubules and adjacent to them. Further, the matching Ca and diffraction profiles demonstrated that all of the Ca is in cAp or that any noncrystalline Ca was uniformly distributed throughout the dentin. Variation of 00.2 and 11.2+21.1+30.0 diffracted intensity was consistent with the expected biaxial crystallographic texture. Extension of x-ray mapping from near 1 μm resolution to the 250 nm level, performed here for dentin and its tubules, will provide new understanding of other mineralized tissues.