In vitro anti- and pro-oxidative effects of natural polyphenols.

The anti- and pro-oxidative effects of phenolic compounds and antioxidants were studied in two different in vitro model systems utilizing ethyl linoleate and 2'-deoxyguanosine (2'-dG) as oxidative substrates, and a Fenton reaction (H2O2, Fe2+) to initiate oxidation. Oxidation of the biomolecules in both model systems exhibited dose dependency. In the 2'-dG assay, oxidation was closely related to H2O2 generation, which occurred during autoxidation of the phenolics.

Selective inhibition of NS-398 on prostanoid production in inflamed tissue in rat carrageenan-air-pouch inflammation.

NS-398 (N-(2-cyclohexyloxy-4-nitrophenyl) methane sulphonamide), a newly synthesized potent non-steroidal anti-inflammatory drug (NSAID) has a much lesser degree of toxicity, as compared with presently available NSAIDs. We have investigated the inhibition of prostanoid production in inflammatory exudate, gastric mucosa and renal papillary tissue, following oral administration to carrageenan-air-pouch rats. The ID50 values of NS-398 in the inflammatory exudate, gastric mucosa and renal papillary tissue were 0.

Simian virus 40 large tumor antigen-immortalized normal human liver epithelial cells express hepatocyte characteristics and metabolize chemical carcinogens.

Normal human liver tissue and cultured human hepatocytes are valuable models to study xenobiotic metabolism and toxicity, but they only have a limited in vitro life-span and are not readily available. This report describes the establishment of replicative cultures of human adult liver epithelial cells in serum-free medium. The longevity of three of these cultures, derived from different donors, was extended by introduction of the simian virus 40 large T antigen gene.

Serum T-kininogen levels increase two to four months before death.

We have reported an accumulation of T-kininogen mRNA in the liver of aging Sprague-Dawley rats. T-kininogen is a cysteine proteinase inhibitor. Since a disruption of the intracellular protein degradation machinery is known to occur during senescence, we wished to further define the role of this protein in the aging process.

Fluorescence polarization immunoassay employing immobilized antibody.

The use of an antibody immobilized on latex or silver colloid in fluorescence polarization immunoassay (FPI) is assessed. In FPI it is possible to detect antigens of high molecular weight because the molecular weight of the antibody is effectively increased. In the assay for rabbit immunoglobulin G a limit of detection lower by two orders of magnitude and an assay range wider by one order of magnitude can be obtained in comparison with conventional FPI.

Genetic transformation of Lactobacillus casei by electroporation.

Lactobacillus casei IAM1045 was transformed with a plasmid pAM beta 1-1, a tra deleted derivative of pAM beta 1, by electroporation. Effective transformation was achieved in electroporation buffers of a wide range of pH values, and in all phases of cell growth tested, with highest frequency in the early log phase. Polyethylene glycol increased the transformation frequency, whereas divalent cations such as Mg2+, Ca2+ and Mn2+ at 0.