ABSTRACTS 483 and that there are two forms of the disease. The terms "persistent" and "late onset" are now generally accepted as describing these two types. The causes of post-adolescent acne remain to be fully elucidated and hormones, colonisation by resistant bacteria and the use of cosmetics have been put forward and debated in the literature. Additionally, some clues to the cause of post-adolescent acne may be gleaned from an individual's response to therapy. Perhaps one of the most intriguing explanations for the increase in this disease is the proposed relationship between increasing stress levels, androgen hormones and increasing levels of acne found in women in fast paced jobs. Amphiphilic Association Structures In A Model Skin Lotion With Hydroxy-Acids *Abeer A1-Bawab, #Stig E. Friberg *Chemistry Department, Faculty of Science, University of Jordan, Amman, Jordan, #Chemistry Department, Faculty of Science, Clarkson University, Potsdam 13699, NY, U.S.A The phase diagrams were determined of lactic and isohexanoic hydroxy- acids as well as salicylic acid with water, a nonionic surt•ctant and a paraffinic oil to outline the influence of the hydroxy-acids on the structure in a model for a skin lotion. The results showed the influence of the acid to be similar to that of the oil, but that the difference in chain length between the two alpha acids had only insignificant influence. The results are discussed from two aspects the structures involved in the lotion as applied and the action of the lotion residue on the skin after the evaporation of the water. Generation Of Volatile Fatty Acids By Axillary Bacteria A.G. James, D. Ityliands and H. Johnston* Unilever R&D Colworth, Colworth House, Shambrook, Bedford MK44 1LQ, U.K. *Current affiliation: University of Abertay, Dundee, UK) Presented in part at the 22 nd IFSCC Congress, Edinburgh 2002 It is generally accepted that short chain (C2-C•) volatile fatty acids (VFAs) are among the causal molecules of axillary malodour. It is also widely acknowledged that malodour generation is attributable to the biotransformation of odourless natural secretions, into volatile odorous products, by axillary bacteria. However, little information is available on the biochemical origins of VFAs on axillary skin. In these studies, assay systems were developed to investigate the generation of VFAs from substrates readily available to the bacteria resident on axillary skin. Propionibacteria and staphylococci were shown to ferment glycerol and lactic acid to the short chain (C2-C3) VFAS, acetic and propionic acid. Furthermore, staphylococci are capable of converting branched aliphatic amino acids, such as leucine, to highly odorous short chain (C4-C•) methyl- branched VFAs, such as isovaleric acid, which are traditionally associated with the acidic note of axillary malodour. However, in vitro kinetic data indicates that these pathways contribute less to axillary VFA levels, than fatty acid biotransformations by a recently defined sub- group of the Corynebacterium genus, corynebacteria (A). The results of these studies provide new understanding on the biochemical origins of VFA-bascd axillary malodour which, in turn, should lead to the development of novel deodorant systems.

j. Cosmet. Scio, 55,485-507 (September/October 2004) Papers Presented at the Annual Scientific Seminar of the Society of Cosmetic Chemists (Saturday's Program) May 7-8, 2004 Mohegan Sun Uncasville, Connecticut 485