Abstract: A process is disclosed for determining the phototoxicity and/or photosensitivity of substances or substance mixtures, involving putting the chemical substance or substance mixture into contact with a non-human vertebrate embryo or tissues or tissue components of a vertebrate embryo, except for human skin cell cultures, whereby, following the contact, there is also a treatment with electromagnetic radiation ranging from 1 mm to 200 nm, followed by evaluation of the pathology of the embryo, tissue or cell; also disclosed is the use of a non-human vertebrate embryo or tissues or tissue components of such an embryo, except for human cell cultures, for purposes of determining the phototoxicity and/or photosensitivity of chemical substances/substance mixtures.

Abstract: A method for atopy prophylaxis involves administering an agent comprising .gamma.-linolenic acid, dihomo-.gamma.-linolinic acid, the physiologically compatible salts, esters, amides, phospholipids, glycolipids thereof, and/or prostaglandin E.sub.1 (PGE.sub.1), PGE.sub.1 derivatives, PGE.sub.1 analogs to preimmunocompetent humans to prevent the occurrence of atopy. These agents are typically contained in a baby food or are supplied to the baby concurrently. These foods may contain one or more thymus hormones. The use of PGE.sub.1, its derivatives and analogs and the physiologically compatible esters, amides, phospholipids and glycolipids thereof in a pharmacologically effective dosage form for the topical or inhalative treatment of acute manifest atopy in the dermal and mucosal areas. These substances are preferably used in combination with .gamma.-linolinic acid, and dihomo-.gamma.-linolinic acid, and/or the physiologically compatible salts, esters, amides, phospholipids and glycolipids thereof.