Photodynamic therapy of Barrett's esophagus: ablation of Barrett's mucosa and reduction in p53 protein expression after treatment.

Background: The effectiveness of photodynamic therapy (PDT) for ablation of high grade dysplasia (HGD) in Barrett's esophagus (BE) is typically reported histologically. Following successful PDT, Barrett's mucosa is replaced with neosquamous mucosa. The objective of this study was to compare the expression of p53 protein in neosquamous mucosa as compared to that in HGD samples not treated with PDT.

Laser-induced fluorescence spectroscopy for in vivo diagnosis of non-melanoma skin cancers.

Background And Objectives: Laser-induced fluorescence spectroscopy is a non-invasive technique previously used for detection of cancer in a variety of organ systems. The objective of this study was to determine whether in vivo laser-induced fluorescence spectroscopy alone at the visible excitation wavelength of 410 nm could be used to detect non-melanoma skin cancers.

Study Design/materials And Methods: The system consisted of a nitrogen/dye laser tuned at 410 nm, an optical multichannel analyzer, and a fiber optic probe for excitation of tissue and collection of fluorescence emission.