Demographic characteristics according to endoscopic BE and pathological BE in the training cohort^*.

<p>^*Data shown are mean (SD) for continuous variables and number (percentage) for categorical variables</p>†<p>P for trend test.</p

The coefficients, weights and odds ratios of selected predictors for BE.

<p>^*n/a: not applicable.</p

Summary of the predictors for BE in the external validation cohort^*.

<p>^*Data shown are mean (SD) for continuous variables and number (percentage) for categorical variables.</p

ROC curve for a) endoscopically visible CLE of any length independent of histology (AUC: 0.61), b) segment containing IM≥2 cm (AUC: 0.64) in the external validation cohort (N = 477).

<p>ROCs curve were developed using the risk scores which are calculated by the weights of different predictors. The weights were developed based on the coefficients of predictors in the backward logistic regression model in the training cohort.</p

ROC curve for a) endoscopically visible CLE of any length independent of histology (AUC: 0.72), b) segment containing IM≥2 cm (AUC: 0.81) in the training cohort (N = 1603).

<p>ROCs curve were developed using the risk scores which are calculated using the weights of different predictors. The weights were developed based on the coefficients of predictors in the backward logistic regression model in the training cohort.</p

Development of Photodynamic Antimicrobial Chemotherapy (PACT) for <i>Clostridium difficile</i>

<div><p>Background</p><p><i>Clostridium difficile</i> is the leading cause of antibiotic-associated diarrhoea and pseudo membranous colitis in the developed world. The aim of this study was to explore whether Photodynamic Antimicrobial Chemotherapy (PACT) could be used as a novel approach to treating <i>C</i>. <i>difficile</i> infections.</p><p>Methods</p><p>PACT utilises the ability of light-activated photosensitisers (PS) to produce reactive oxygen species (ROS) such as free radical species and singlet oxygen, which are lethal to cells. We screened thirteen PS against <i>C</i>. <i>difficile</i> planktonic cells, biofilm and germinating spores <i>in vitro</i>, and cytotoxicity of effective compounds was tested on the colorectal adenocarcinoma cell-line HT-29.</p><p>Results</p><p>Three PS were able to kill 99.9% of bacteria in both aerobic and anaerobic conditions, both in the planktonic state and in a biofilm, after exposure to red laser light (0.2 J/cm²) without harming model colon cells. The applicability of PACT to eradicate <i>C</i>. <i>difficile</i> germinative spores indirectly was also shown, by first inducing germination with the bile salt taurocholate, followed by PACT.</p><p>Conclusion</p><p>This innovative and simple approach offers the prospect of a new antimicrobial therapy using light to treat <i>C</i>. <i>difficile</i> infection of the colon.</p></div

Mechanism of PACT (A) and post PACT live/dead viability assay on <i>C</i>. <i>difficile</i> with light only (B), and PB031 (C) staining alive (green) and dead (red) bacteria.

<p>Scale bars represent 10 μM.</p

(A) PACT on <i>C</i>. <i>difficile</i> spores; viable count of germinated <i>C</i>. <i>difficile</i> post PACT (100 μM PS, 665nm,) after different incubation times with 0.1% taurocholate. (B) Number of bacteria within a <i>C</i>. <i>difficile</i> biofilm after PACT (100 μM or 1mM PS, 665nm, 0.24 or 1.4 J/cm²).

<p>Bars represent the mean of three biological repeats and the error bars indicate SEM, * p < .05, ** p < .001.</p

Absorbance spectra of PS in either DMSO (solid line) or BHI (dashed line), overlaid is the relevant laser excitation wavelength in red at 665nm 652nm or 784nm.

<p>For spectra comparison, all PS solutions were diluted to 50 μM concentration except Chlorin-e6, PPa and PB067 (25μM), S2 and S4 (6.7 μM), and PB066 (8.35 μM).</p

The effect of cell washing on PACT-mediated killing of <i>C</i>. <i>difficile</i> (strain R20291) by different PS; < 1 log₁₀ killing (-); > 4 log₁₀ killing (+++)

<p>The effect of cell washing on PACT-mediated killing of <i>C</i>. <i>difficile</i> (strain R20291) by different PS; < 1 log₁₀ killing (-); > 4 log₁₀ killing (+++)</p