title: Histopathological confirmation of similar intramucosal distribution of fluorescein in both intravenous administration and local mucosal application for probe-based confocal laser endomicroscopy of the normal stomach.
abstract: Probe-based confocal laser endomicroscopy (pCLE) is capable of acquiring in vivo magnified cross-section images of the gastric mucosa. Intravenous injection of fluorescein sodium is used for confocal imaging. However, it is still under debate if local administration of the dye to the mucosa is also effective for confocal imaging as it is not yet clear if topical application also reveals the intramucosal distribution of fluorescein. The objective of this study was to evaluate the intramucosal distribution of fluorescein sodium after topical application and to compare the distribution to the conventional intravenous injection used for confocal imaging. pCLE of the stomach uninfected with Helicobacter pylori was performed in a healthy male employing intravenous administration and local mucosal application of fluorescein. The mucosa of the lower gastric body was biopsied 1 min and 5 min after intravenous administration or local mucosal application of fluorescein, and the distribution of fluorescein in the biopsy samples was examined histologically. Green fluorescence was already observed in the cytoplasm of fundic glandular cells in the biopsied deep mucosa 1 min after local mucosal application of fluorescein. It was also observed in the foveolar lumen and inter-foveolar lamina propria, although it was noted at only a few sites. In the tissue biopsied 5 min after the local mucosal application of fluorescein, green fluorescence was more frequently noted in the cytoplasm of fundic glandular cells than in that 1 min after the local mucosal application of fluorescein, although obvious green fluorescence was not identified in the foveolar lumen or inter-foveolar lamina propria. The distribution of intravenously administered fluorescein in the cytoplasm of fundic glandular cells was also clearly observed similarly to that after local mucosal application of fluorescein. Green fluorescence in more cells was observed in many cells 5 min after intravenous administration compared with that after 1 min. The presence of fluorescein in the mucosa was observed within a short time after local mucosal application of fluorescein, suggesting that pCLE images similarly to those after intravenous fluorescein administration can be acquired by local mucosal application of fluorescein.
authors.affiliation: Kouichi Nonaka, Ken Ohata, Yohei Minato, Tomoaki Tashima, Yasushi Matsuyama, Maiko Takita, Nobuyuki Matsuhashi, Department of Gastroenterology, NTT Medical Center Tokyo, Tokyo 141-8625, Japan.
authors.forename: Kouichi
authors.initials: K
authors.lastname: Nonaka
authors.affiliation: Kouichi Nonaka, Ken Ohata, Yohei Minato, Tomoaki Tashima, Yasushi Matsuyama, Maiko Takita, Nobuyuki Matsuhashi, Department of Gastroenterology, NTT Medical Center Tokyo, Tokyo 141-8625, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Ohata
authors.affiliation: Kouichi Nonaka, Ken Ohata, Yohei Minato, Tomoaki Tashima, Yasushi Matsuyama, Maiko Takita, Nobuyuki Matsuhashi, Department of Gastroenterology, NTT Medical Center Tokyo, Tokyo 141-8625, Japan.
authors.forename: Shinichi
authors.initials: S
authors.lastname: Ban
authors.affiliation: Kouichi Nonaka, Ken Ohata, Yohei Minato, Tomoaki Tashima, Yasushi Matsuyama, Maiko Takita, Nobuyuki Matsuhashi, Department of Gastroenterology, NTT Medical Center Tokyo, Tokyo 141-8625, Japan.
authors.forename: Shin
authors.initials: S
authors.lastname: Ichihara
authors.affiliation: Kouichi Nonaka, Ken Ohata, Yohei Minato, Tomoaki Tashima, Yasushi Matsuyama, Maiko Takita, Nobuyuki Matsuhashi, Department of Gastroenterology, NTT Medical Center Tokyo, Tokyo 141-8625, Japan.
authors.forename: Rumi
authors.initials: R
authors.lastname: Takasugi
authors.affiliation: Kouichi Nonaka, Ken Ohata, Yohei Minato, Tomoaki Tashima, Yasushi Matsuyama, Maiko Takita, Nobuyuki Matsuhashi, Department of Gastroenterology, NTT Medical Center Tokyo, Tokyo 141-8625, Japan.
authors.forename: Yohei
authors.initials: Y
authors.lastname: Minato
authors.affiliation: Kouichi Nonaka, Ken Ohata, Yohei Minato, Tomoaki Tashima, Yasushi Matsuyama, Maiko Takita, Nobuyuki Matsuhashi, Department of Gastroenterology, NTT Medical Center Tokyo, Tokyo 141-8625, Japan.
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Tashima
authors.affiliation: Kouichi Nonaka, Ken Ohata, Yohei Minato, Tomoaki Tashima, Yasushi Matsuyama, Maiko Takita, Nobuyuki Matsuhashi, Department of Gastroenterology, NTT Medical Center Tokyo, Tokyo 141-8625, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Matsuyama
authors.affiliation: Kouichi Nonaka, Ken Ohata, Yohei Minato, Tomoaki Tashima, Yasushi Matsuyama, Maiko Takita, Nobuyuki Matsuhashi, Department of Gastroenterology, NTT Medical Center Tokyo, Tokyo 141-8625, Japan.
authors.forename: Maiko
authors.initials: M
authors.lastname: Takita
authors.affiliation: Kouichi Nonaka, Ken Ohata, Yohei Minato, Tomoaki Tashima, Yasushi Matsuyama, Maiko Takita, Nobuyuki Matsuhashi, Department of Gastroenterology, NTT Medical Center Tokyo, Tokyo 141-8625, Japan.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Matsuhashi
authors.affiliation: Kouichi Nonaka, Ken Ohata, Yohei Minato, Tomoaki Tashima, Yasushi Matsuyama, Maiko Takita, Nobuyuki Matsuhashi, Department of Gastroenterology, NTT Medical Center Tokyo, Tokyo 141-8625, Japan.
authors.forename: Helmut
authors.initials: H
authors.lastname: Neumann
keywords: Confocal laser endomicroscopy; Distribution; Fluorescein; Intravenous; Local application