Background: Photodynamic therapy (PDT) involves the activation of a photosensitiser by visible light to produce activated oxygen species within target cells, resulting in their destruction. Evidence-based guidelines support the efficacy of PDT using topical 5-aminolaevulinic acid (ALA-PDT) in actinic keratoses, Bowen's disease and basal cell carcinoma (BCC). Efficacy for nodular BCC appears inferior to that for superficial BCC unless prior debulking or repeat treatments are performed.The aim of this study was to assess the safety and efficacy of adding a novel iron chelating agent, CP94 to topical ALA, to increase the accumulation of the photosensitiser in the tumour.Observations: Enhanced PDT using 40% CP94 resulted in significantly greater clearance rates in nodular BCC than with ALA-PDT alone, in our protocol of single treatment PDT with no lesion preparation. Conclusion:The results of this study demonstrate the safe and effective use of an enhanced ALA-PDT protocol for nodular BCC using CP94, with no adverse reactions to this modification. This is the first time this formulation has been used in patients.This formulation is now the focus of further study.

Aim/hypothesis. Radiobinding assays (RBA) are unable to differentiate insulin autoantibodies (IAA) from insulin antibodies (IA). We sought to establish whether random peptide phage display might generate reagents with which to distinguish IAA idiotopes from IA idiotopes. Methods. Two insulin-binding sera were used to select phagotopes from a phage library. The first, designated IAS, came from an insulin-treated patient with the insulin autoimmune syndrome, and was known to contain both IA and a high titre of human insulin specific (B30 threonine dependent) IAA. The second, designated IDD, was taken from a newly-diagnosed IAA + Type 1 diabetic patient. Phage colonies selected by insulin-purified IgG extracts of IAS and IDD were selected at random for DNA sequencing, and tested for their reactivity with insulin antibodies and ability to distinguish disease-associated idiotopes. Results. Seven phagotopes bound IAS and the phagotope designated IAS-9, corresponding to sequence KRSRLDV, gave the highest binding standard deviation (SD) score. Seven phagotopes bound IDD and the phagotope designated IDD-10, corresponding to sequence LGRGGSK, bound most strongly. IAS-9 was able to displace insulin binding in IAS and all of ten insulin-treated Type 2 diabetic patients, but not the IAA present in any of the eight patients with newlydiagnosed Type 1 diabetes. IDD-10, on the other hand, could displace insulin binding detected in the sera of eight patients with untreated Type 1 diabetes (IAA), but not in IAS or sera of the insulin-treated Type 2 diabetics. Conclusion. Phagotopes provide reagents which between them can distinguish positively as well as negatively diabetes-associated IAA from non-diabetes associated IAA and from IA. [Diabetologia (2003) 46:802-809]

This investigation considered a novel method of enhancing penetration of the topical photosensitizing agent methyl aminolevulinate (MAL) into nodular basal cell carcinomas (BCCs) using an oxygen pressure injection device. Oxygen pressure injection (OPI) is a method to drive compounds into skin using pressured oxygen. The study was an observer-blinded pilot of a single application of MAL to nBCCs, with or without the use of OPI. The BCCs were then excised at different time intervals (0-180 min) and the depth of penetration of the MAL examined using microscopic fluorescence photometry to detect the production of the naturally fluorescent active photosensitiser protoporphyrin IX (PpIX). A highly selective and homogeneous distribution of MAL-induced porphyrin fluorescence was seen in all nBCC tumors studied, and showed a high lesion-to-normal-tissue ratio with very little fluorescence in the surrounding normal tissue. Although it was difficult to compare quantitatively, as individual tumors in each of the different study groups varied, a definite trend of increase in relative tumor concentration of MAL-induced PpIX was observed over time, and this was enhanced when OPI was employed.

Insulin autoantibodies (IAA) are present in type 1 diabetes (T1D) and other autoimmune diseases. The differences in the IAA epitopes in various clinical diseases have not been evaluated. We used phage display to select phagotopes specific to IAA from a newly diagnosed T1D child (designated FPP) and from an adult-onset T1D subject with autoimmune polyendocrine syndrome type 2 (APS-II). The phagotopes randomly selected were tested as antiidiotope reagents to displace human radiolabeled insulin in the microfiltration radiobinding assay using IAA(+) sera from T1D subjects and insulin antibody (IA(+)) sera from insulin-treated type 2 diabetes subjects. The DNA of the phagotopes selected from the FPP and APS sera revealed consensus amino acid sequences of GRG and LGKRS, respectively. Phagotope FPP-10 displaced insulin binding in 90% of IAA(+) subjects but not in the IA(+) or the APS subject. Phagotope APS-4 was able to displace insulin binding from the APS subject but not in the IAA(+) or IA(+) subjects. We have demonstrated antiidiotope reagents able to distinguish childhood-onset T1D-associated IAA(+) from adult-onset T1D (APS-II-associated IAA(+)) that are different from their specificity for human insulin and from its antiidiotope amino acid sequence.

We have established the principle of using phage display in the investigation of insulin antibodies during remission in Type 1 diabetes. The immunological characteristics of IA 3 months after the introduction of insulin treatment were different from those at diagnosis of Type 1 diabetes (IAA). Using phage display technology, it was not possible to distinguish insulin antibodies according to remission status.