Performance of enzymatic fuel cell in cell culture.

Here we present the very first study of an enzymatic fuel cell (EFC) in a cell culture. An EFC with Corynascus thermophilus cellobiose dehydrogenase (CDH) based bioanode and Myrothecium verrucaria bilirubin oxidase (BOx) based biocathode was constructed at the bottom of a medusa cell culture plate. The constructed EFC had a power density of up to 25 µW cm(-2) at 0.5 V potential in simple buffer solution and in cell culturing medium. L929 murine fibroblast cells were seeded on top of the EFC and possible effects of the EFC on the cells and vice versa were studied. It was shown that on average the power of the EFC drops by about 70% under a nearly confluent layer of cells. The EFC appeared to have a toxic effect on the L929 cell line. It was concluded that the bioanode, consisting of CDH, produced hydrogen peroxide at toxic concentrations. However, the toxic effect was circumvented by co-immobilizing catalase on the bioanode.

Intestinal permeability and bacterial growth of the small bowel in patients with primary sclerosing cholangitis.

OBJECTIVE: Animal studies show that small intestinal bacterial overgrowth and infusion of bacterial antigens into portal blood cause hepatic histological changes similar to those seen in primary sclerosing cholangitis in man. It has been suggested that aa similar mechanism involving bacterial overgrowth with increased small-bowel permeability may play a pathogenic role in patients with primary sclerosing cholangitis (13 M, 9 F, median age 37 years, range 21-74 years), 19 of whom (83%) had quiescent inflammatory bowel disease, were included in the study along with 18 healthy volunteers (9 F, ( M, median age 36 years, range 23-80 years). Small-bowel bacterial overgrowth was defined as the presence of colonic flora>10(5) colony-forming units (cfu)/ml from duodenal aspirations. Small-bowel intestinal permeability was assessed as the differential urinary excretion of lactulose/L-rhamnose. RESULTS: Bacterial overgrowth was evident in one patient with primary sclerosing cholangitis (4.5%) (Enterobacter) and in none of the controls. Intestinal permeability in patients with primary sclerosing cholangitis (0.034 (0.026-0.041) (median, interquartile range (IQR)) did not differ significantly from that of the controls (0.033 (0.025-0.041). CONCLUSIONS: Small intestinal bacterial overgrowth and increased intestinal permeability does not seem to play an important pathogenic role in patients with primary sclerosing cholangitis.