Topical protoporphyrin (PpIX)-induced photodynamic therapy (PDT) relies on the penetration of the prodrug into the skin lesion and subsequent accumulation of the photosensitizer. Methyl aminolevulinate (MAL)-PDT is an established treatment for thinner and superficial non-melanoma skin cancers (NMSCs) but for the treatment of the thicker nodular basal cell carcinoma (nBCC) enhanced penetration of the prodrug is required. This study employed a new higher pressure, oxygen pressure injection (OPI) device, at the time of Metvix® application with a view to enhancing the penetration of MAL into the tumors. Each patient had Metvix® applied to a single nBCC followed by application of a higher pressure OPI device. Following different time intervals (0, 30, 60, 120 or 180 min) the tumors were excised. The maximum depth and area of MAL penetration achieved in each lesion was measured using PpIX fluorescence microscopy. As expected, an increase in the depth of MAL-induced PpIX accumulation and area of tumor sensitized was observed over time; when the Metvix® cream was applied for 0, 30, 60, 120 and 180 min the median depth of PpIX fluorescence was 0%, 21%, 26.5%, 75.5% and 90%, respectively and the median area of tumor sensitized was 0%, 4%, 6%, 19% and 60%, respectively. As the investigation presented here did not include a control arm, the relative depths of fluorescence observed in this study were statistically compared (using the non-parametric Mann Whitney U test) with the results of our previous study where patients had Metvix® cream applied either with or without the standard pressure OPI device. When the higher pressure OPI device was employed compared to without OPI this increase was observed to be greater following 30, 120, and 180 min although overall not significantly (p = 0.835). In addition, no significant difference between the higher pressure OPI device employed here and the previously investigated standard pressure OPI device was observed (p = 0.403). However, when the results for both OPI devices were combined and compared to the standard treatment (no OPI employed) group, although the difference did not reach significance (p = 0.531) a consistent and substantial increase in the depth of PpIX fluorescence was observed, therefore employment of an OPI device during topical MAL-PDT protocols warrants further investigation as a technique for enhancing MAL penetration.

Background This pilot study was carried out to determine whether Helicobacter pylori can be detected in normal colon or in association with colorectal neoplasia. Methods Paraffin processed colonic tissue blocks of normal colonic mucosa (n = 60), and patients diagnosed as adenoma (n = 60), and adenocarcinoma (n = 60) were retrieved from our archive; the adenoma group included tubular (n = 20), tubulovillous (n = 20) and villous adenomas (n = 20). 4 μm sections were stained by immunohistochemical methods using anti- Helicobacter pylori antibodies (polyclonal NCL-HPp and monoclonal NCL-C-jejuni). Results Significant numbers of Helicobacter pylori were identified in tubular adenomas (OR = 11.13; 95%CI = 1.62–76.70), tubulovillous adenomas (OR = 10.45; 95%CI = 1.52–71.52) and adenocarcinomas (OR = 8.13; 95%CI = 1.40–46.99) compared to controls: there was no association in numbers of Helicobacter pylori and villous adenomas (OR = 2.95; 95%CI = 0.29–9.96). Conclusion We conclude that although, in this pilot study, there appears to be an association in the prevalence of Helicobacter pylori with some, but not all, colorectal neoplasms, we can not infer causality from these results. These findings need to be further substantiated with a prospective study and the use of molecular biological techniques to determine a causal association.