Effect of different feed ingredients and additives on IPEC-J2 cells challenged with an enterotoxigenic Escherichia coli strain.

The intestinal porcine epithelial cell line IPEC-J2 was used as an in vitro model to assess effects of additives on the adhesion and cell toxic effects of a F4-positive (ETEC) and a F4-negative Escherichia coli (DSM 2840) strain. Bacterial adhesion was examined using flow cytometry in IPEC-J2 cells infected with bacteria stained with 5,6-carboxymethyl fluorescein diacetate succinimidyl ester. Measurement of transepithelial electrical resistance (TEER) was performed to characterize the impact on IPEC-J2 monolayer integrity. The feed additives were prepared as aqueous extract and tested in different dilutions and incubation times. The F4-positive ETEC strain had a high adhesion to IPEC-J2 cells and reduced TEER shortly after the in vitro infection. The nonpathogenic E. coli strain DSM 2840 showed only low adhesion capacity and no TEER impairment. Infection with ETEC with added test extracts showed a reduction of bacterial adhesion to IPEC-J2 cells by an autolyzed yeast product (p < 0.05). Bovine colostrum, an additive containing thyme extract and an organic acid mix did not interfere with the ETEC adherence. The TEER decrease of the IPEC-J2 monolayer after ETEC infection was not affected by the added substances. In conclusion, interference with epithelial adhesion might be a protective mechanism of the tested yeast extract, indicating that the cell culture model might be suitable as screening tool to complement in vivo challenge trials with piglets.

[Minerals in normal and cirrhotic liver. The pathology of mineral dependent athrocytic liver cirrhosis]. / Vergleichende Untersuchungen zum Mineralgehalt der normalen und zirrhotischen Leber. Ein Beitrag zur Pathologie mineralabhängiger athrozytotischer Leberzirrhosen.

Concentrations of iron, copper and zinc were measured in postmortem specimens of liver, muscle and brain tissue by atomic absorption spectrophotometry. Concentrations varied markedly in normal liver specimens from person to person, but not in other organ specimens. Copper concentrations in specimens from cirrhotic livers were normal in most cases, however at the upper limit of normal in about 20% of the cases evaluated. Concentrations of zinc and iron were lower than normal in cirrhotic livers. Mineral concentrations were higher by a factor of 10-20 in liver specimens of patients with hemochromatosis or M. Wilson than in normals. Iron overloading as a consequence of therapy (secondary hemochromatosis) and liver changes due to longtime artificially elevated plasma copper levels may imitate the adult form of the "classic" mineral storage diseases mentioned. Thus "athrocytotic" liver cirrhosis, being caused or accompanied by metal excess has to be considered as a polyetiological syndrome.