Glutathione as a mediator of the in vitro cytotoxicity of a green tea polyphenol extract.

ABSTRACT The 24-hr cytotoxicities of a green tea polyphenol (GTP) extract to cell lines derived from the human oral cavity were assessed using the neutral red (NR) assay. The sequence of sensitivity was carcinoma HSC-2 cells > immortalized gingival GT1 fibroblasts > normal gingival HGF-2 fibroblasts. The GTP extract generated hydrogen peroxide (H(2)O(2)) in cell culture medium and in phosphate buffer, albeit to a lesser extent.

[Classification of the avian summer population of the Western Siberian plain].

The proposed classification system reflects the difference between the three population systems: unbuilt land, built-up land, and aquatic-semiaquatic communities. Two superorder groups--north and median--further divided into types were recognized in each of the systems. Most types are divided into subtypes, classes, and subclasses (and sometimes genera of the population).