[Confocal laser-scanning microscopy to analyse the epithelium of the tongue]. / Konfokale Laser-Scanning-Mikroskopie zur Beurteilung des Zungenepithels.

BACKGROUND: Superficial changes of the epithelium of the tongue are diagnosed by biopsy. The aim of this in-vivo study was to show the normal epithelium, the subepithelial structures and the subepithelial vessels of the tongue using confocal microscopy. METHODS: A digital confocal Laser-Scanning Microscope (LSM), a combination of the Heidelberg Retina Tomograph HRT II and the Rostock Cornea Module (Heidelberg Engineering GmbH) was used. This digital microscope makes computer-based external hydraulic z-scan possible and the automatic collection of patient-based video sequences and the 3D reconstruction of the structures of the fungiform papilla. 800-fold magnifications are possible using a water immersion lens (Zeiss, 63-fold). A parabolic plexiglass disc with holes and a video camera were used to stabilize the tongue and to control the contact between the tongue surface and the contact element of the lens. PATIENTS: Confocal microscopy was performed on 17 healthy test volunteers aged 21 to 56. RESULTS: First findings with confocal LSM as a contact procedure show that a precise identification of the fungiform and filiform papillae and 3D reconstruction of the pores is possible. Furthermore, different cell layers of the tongue epithelium, subcellular structures of the epithelium and the subepithelial vessels to depth of 50 microm can be visualized by the erythrocytic flow and a max. 800-fold magnification. CONCLUSIONS: The confocal LSM is a nondestructive contact procedure and allows the in-vivo analysis of the tongue epithelium.

The renal and systemic hemodynamic effects of a nitric oxide-synthase inhibitor are reversed by a selective endothelin(a) receptor antagonist in men.

There is evidence for an interaction between nitric oxide (NO) and endothelin (ET) at the level of the renal vasculature. We hypothesized that acute renal effects of systemic NO synthase inhibition (NG-monomethyl-l-arginine, L-NMMA) may be blunted by coadministration of a specific ET(A) receptor antagonist (BQ-123) in healthy humans. Fifteen healthy young male subjects participated in this randomized, double-blind, placebo-controlled 3-way crossover study. These sodium-repleted volunteers received L-NMMA alone, or BQ-123 alone, or L-NMMA with a subsequent coinfusion of BQ-123. Renal plasma flow (RPF) and glomerular filtration rate (GFR) were determined with the PAH and inulin clearance method, respectively. Mean arterial pressure (MAP) and pulse rate were measured noninvasively at baseline and every 15 min after the start of the study period. L-NMMA alone reduced RPF (-22%, P < 0.001) and GFR (-8%, P < 0.009) and increased MAP (+10%, P < 0.001). BQ-123 alone did not affect these parameters. However, coinfusion of BQ-123 blunted the effects of L-NMMA on RPF (P < 0.001), GFR (P < 0.001), and MAP (P = 0.006). Peripheral and renal hemodynamic effects of acute systemic NO synthase inhibition are at least partially reversed by ET(A) receptor blockade with BQ-123. This indicates a functional antagonism between specific ET(A) receptor antagonist and NO synthase inhibitors at the level of the renal vasculature.