Inhibition of thyroid hormone uptake by calcium antagonists of the dihydropyridine class.

A series of substituted 4-phenyl-1,4-dihydropyridines 2a-m was tested for their inhibitory effects on L-triiodothyronine (L-T3) uptake by human HepG2 hepatoma cells. The most potent compounds were the nitro-substituted derivatives 2,6-dimethyl-4-(4'-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid 3-ethyl ester 5-methyl ester (2m) and the well-known calcium antagonists nitrendipine (2k) and nifedipine (2j) with an uptake inhibition between 80.5 and 85.

Procedure for the purification of streptavidin by hydrophobic interaction chromatography.

A procedure is described for the purification of hydrophobic microbial proteins such as streptavidin from Streptomyces avidinii, using Benzyl-DC bead cellulose as the column material. The separation is rapid with a high loading capacity and sufficient resolution for preparative uses. Advantages are discussed especially for industrial purposes.

[The dependence of the physiological properties of Trichophyton mentagrophytes on the pH value of the culture medium].

The growth, the amino acid degradation in the medium and the incorporation of amino acid nitrogen as a function of the pH-value were studied. At a higher pH-value, the growth and metabolism accelerate. During the growth, the pH-value of the medium temporarily increases.